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Showing papers in "Journal of analytical and bioanalytical techniques in 2016"


Journal ArticleDOI
TL;DR: This work presents a proof-of-concept device for everyday analysis of biological or chemical samples that can detect range of analytes quickly with the help of transducers that converts the biological response into measurable analytical signals.
Abstract: Volume 7 • Issue 2 • 1000e125 J Anal Bioanal Tech ISSN: 2155-9872 JABT, an open access journal Imagine an era where patients will be able to tell the doctor that they themselves have detected the target molecule (e.g., antigen, proteins, chemical molecule, etc.) related to a disease using a personalized diagnostic tools (e.g., glucose for diabetes, Salmonella typhi for typhoid, bilirubin for anemia). This may help the clinicians to quickly design the adequate therapeutic strategies for patients. A biosensor based diagnostic technology promises to do just that-quick onsite diagnosis. Biosensors in general are stand alone miniature portable devices that can detect range of analytes quickly with the help of transducers that converts the biological response into measurable analytical signals. It represents a rapidly expanding field currently and is expected to reach $22.68 billion market by 2020. Moving this proof-of-concept device for everyday analysis of biological or chemical samples has involved tremendous development in biosensors research [1]. Therefore, many such diagnostic devices are available in the global market for various medical purpose such as; malaria testing kit [(CareStartTM Malaria HRP2/PLDH; Access Bio, United States) (Maleriscan® Malaria Pf/ PAN; Bhat Bio-Tech (P) Ltd., India)], hCG based pregnancy testing kits [(Pregnosis®; Hoffmann-La Roche Ltd., Montreal), (VelocitTM; Dr.Reddy’s India)], and portable glucometers [(CareStartTM G6PD, Access Bio, United States)] etc. Although these miniaturized devices are extensively fabricated and possess good market potential, research to improvise the existing designs in terms of relativity, sensitivity, detection time, and point-of-care diagnosis are still underway [2].

46 citations


Journal ArticleDOI
TL;DR: Biosensors have been broadly studied based on various detection principles such as; conductometric, amperometric, potentiometric, and voltameteric and selection of the biomaterial for designing a biosensing element is an important issue.
Abstract: Volume 7 • Issue 2 • 1000e124 J Anal Bioanal Tech ISSN: 2155-9872 JABT, an open access journal Biosensors are finding diverse applications and gradually becoming an integral part in a variety of analytical applications such as; clinical diagnosis, environmental monitoring, etc. since the introduction of glucose biosensors by Clark and Lyons in 1960 [1]. This was followed by the inception of the first enzyme-based glucose sensor developed by Updike and Hicks in 1967. Since then, extensive researches have been done towards biosensor designing due to its specificity, fast detection time, and high selectivity to detect analytes (DNA/RNA, proteins, cells), within the miniaturized settings [2]. A biosensor typically consists of a transducer in combination with a biologically active molecule that converts the biochemical response into a quantifiable signal. In general, a biosensor is comprised of three basic components viz. (i) a detector, (ii) a transducer, and (ii) a signal processor. The transducer can be electrochemical, optical, acoustic, or calorimetric type depending upon the diagnosis and the physiochemical character of the analyte [3]. Biosensors have been broadly studied based on various detection principles such as; conductometric, amperometric, potentiometric, and voltameteric [4]. The selection of the biomaterial for designing a biosensing element is an important issue. Among these, enzymes [5], DNA/RNA [6], aptamers [7,8], antibodies [9], receptors [10], organelles [11] and animal cells/tissues [12] have been extensively utilized to develop various types of sensing systems. Studies have been reported on glucose biosensors [13], sensors for cancer detection [14,15], sensors for detection of various drugs such as kanamycin [16], daunomycin [17], and acetaminophen [18] using different types of biomaterials.

21 citations


Journal ArticleDOI
TL;DR: In this article, a chitosan-Fe3+ complex with high chemical stability material was synthesized and the performance towards Fluoride adsorption was evaluated by batch experiments.
Abstract: In this study highly efficient sorbent, chitosan-Fe3+ complex with high chemical stability material was synthesized and the performance towards Fluoride adsorption was evaluated by batch experiments. The adsorption process reached equilibrium at 1 hour. The maximum adsorption capacity reached 2.34 mg/g of F- at an initial concentration of 50 mg/L of F- and adsorbent dosage of 10 g/L. Moreover, no significant change in the fluoride removal efficiency was observed in the pH range of 3.0-10.0. The adverse influence of sulphate on fluoride removal was the most significant, followed by bicarbonate and nitrate, whereas chloride had slightly adverse effect. Adsorption process followed the pseudo-second-order kinetic model, and the experimental equilibrium data were fitted well with the Langmuir-Freundlich and D-R isotherm models. Thermodynamic parameters revealed that fluoride adsorption was a spontaneous and exothermic process. The chitosan-Fe3+ complex could be effectively regenerated by NaCl solution.

17 citations


Journal ArticleDOI
TL;DR: Fungal load in sesame seeds increased with latitude, aflatoxin levels in millet and sorghum varied with temperature and relative humidity, and Aspergillus niger, Fusarium and Pennicilium showed resistance to tannin.
Abstract: Incidence of fungi and aflatoxin in sorghum, millet, sesame and their products in Northern Nigeria was investigated in 146 food samples including; sorghum and traditional beer (50), millet and millet dough (50), and sesame seed (50). Members of the Aspergillus, Fusarium, Pennicilium, Macrophomena, Cercospora, Phoma, Rhizopus, Alternaria and Curvularia species in order of predominance were identified. Aflatoxin analysis showed 28.6% sorghum (0.96-21.74 μg/Kg), 80% burukutu (1.27-8.82 μg/Kg), 20% pito (0.69-2.00 μg/Kg), 29% millet grain (1.05-14.96 μg/Kg), 26.3% millet dough (0.81-3.78 μg/Kg) and 21.7% sesame (0.79-60.05 μg/Kg) samples were unsafe for consumption. Fungi and aflatoxin levels were higher in sesame than millet and sorghum. Fungal load in sesame seeds increased with latitude, aflatoxin levels in millet and sorghum varied with temperature and relative humidity. Beer processing reduced the levels of aflatoxin from sorghum grain to beer, establishing a 47% and 25% carryover respectively. Higher tannin levels in the samples correlated with lower fungal loads however, Aspergillus niger, Fusarium and Pennicilium showed resistance to tannin. Legislative, regulatory and stakeholder involvement is key in the continuous effort to reduce the mycotoxin menace.

15 citations


Journal ArticleDOI
TL;DR: This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits the unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Abstract: 9 paginas, 1 tabla, 7 figuras.-- This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

13 citations



Journal ArticleDOI
TL;DR: In this article, 1-methyl-imidazolium di(2-ethylhexyl) phosphate [MIm+][D2EHP-] was synthesized and tested as extractants in the batch removal of mercury (II) from aqueous solution.
Abstract: D2EHP-] and 1-methyl-imidazolium di(2-ethylhexyl) phosphate [MIm+][D2EHP-] were synthesized and tested as extractants in the batch removal of mercury (II) from aqueous solution. The influence of contact time, aqueous to organic phase’s volume ratio, initial concentration of Hg (II), IL concentration, pH levels, ionic strength, and temperature was evaluated. The extraction equilibrium was established in 30 min for [MIm+][D2EHP-] and in 15 min for [BIm+][D2EHP-]. The maximum mercury extraction was obtained at pH 5.81. For the extraction of mercury, [([MIm+] [D2EHP-])5 (HgCl2)]org, [([MIm+][D2EHP-])5 (HgClOH)]org, [([BIm+][D2EHP-])3/2 (HgCl2)]org and [([BIm+][D2EHP-])3/2 (HgClOH)]org species were formed. Regarding the ionic strength for [MIm+][D2EHP-], the results show a significant improvement of the mercury extraction yield (100%) upon the addition of sodium acetate to the aqueous phase in a Na+/Hg2+ mass ratio ranging from 0.1 to 2.0. The relationship between the percentages of the extracted species and the extraction yield was established by calculations using CHEAQS V. L20.1 software. The results revealed a decrease in the extraction yield of Hg (II) with decreasing proportions of HgCl2aq from 65.15 to 40.31% and of HgClOHaq from 31.31 to 0.1%, when NaCl was added. The very important optimal sorption capacities for ([BIm+][D2EHP-]) and ([MIm+][D2EHP]) were 58.39 mg/g and 93.23 mg/g respectively. With a longer alkyl chain on the imidazolinic ring, the decreasing of extraction yield was observed.

10 citations


Journal ArticleDOI
TL;DR: In this paper, the authors have done some important analysis of bio-oil which is obtained from the pyrolysis of agricultural wastes - discarded soybean frying oil, coffee and eucalyptus sawdust in the presence of 5% Hydrogen and Argon.
Abstract: Pyrolysis is a thermal process for converting various biomasses, wastes and residues to produce high-energydensity fuels (bio-oil). In this paper, we have done some important analysis of bio-oil which is obtained from the pyrolysis of agricultural wastes - discarded soybean frying oil, coffee and eucalyptus sawdust in the presence of 5% Hydrogen and Argon. The bio oil was obtained in one step pyrolysis in which temperature of the system kept 15°C and then increased up to 800°C but in two step condensation processes. 1st condensation step is done on temperature 100°C and 2nd is done on 5°C. So we got two types of fractions, HTPO (Oil condensed at high temperature 100°C after pyrolysis) and LTPO (Oil condensed at low temperature 5°C after pyrolysis). After pyrolysis the thermal cracking is done for both types of oil on the same two temperatures, then we again got two type of fractions HTCO (high temperature 100°C condensed oil after cracking) and LTCO (Low temperature 5°C condensed oil after cracking), these fractions are distillated and analyzed in GC-MS. The resulted compounds are given in the paper and are explained with the help of graphs and tables. The ultimate aim of hydrogenation and Argon is to improve stability and fuel quality by decreasing the contents of organic acids and aldehydes as well as other reactive compounds, as oxygenated and nitrogenated species because they not only lead to high corrosiveness and acidity, but also set up many obstacles to applications.

9 citations


Journal ArticleDOI
TL;DR: In this article, the authors experimented with the P. putida ATCC 49128, a bioaugmented organism to treat mercury contaminated samples from two petroleum industry based wastewater, and the results affirmed the ability of this strain to optimally utilize the optimal conditional factors to grow and reduce mercury within a short time of less than 30 hours.
Abstract: Mercury is one of the most poisonous elements found on earth bonded to sulfhydryl groups of enzymes and proteins, thereby inactivating vital cell functions. Indeed this has drawn the attention of many environmental researchers who have been attempting through various mean to expunging mercury from these contaminated medium. Biological approach provided a satisfactory outcome in the clean-up of mercury contaminated soil and water due to its high potential for greater performance, environment friendliness and cost effectiveness. Mercuryresistant bacterial strain (P. putida ATCC 49128), was experimented on its potential to grow and reduce mercury to a permissible level under optimum conditions of nutrient, pH and other related physical factors in an incubator shake flask. It was observed that P. putida displayed a usual growth pattern when tried at low level mercury concentration of 1.0 μM, 6.0 μM and 19.0 μM, by exponentially growing during the first 4 hours of inoculation, but drastically decreased by the end of 24 hours’ time. This was indicated by the mercury removal rate of 99.0%, 99.83% and 98.58% in the three mercury concentrations used. Also, under the same optimum condition of growth, mercury concentration of 1000 μM was reduced by 92.0% after the first initial 1 hour to 98.0% at the end of 28 hour study. Comparably, similar trend was also observed when P. putida was used as bioaugmented organism to treat mercury contaminated samples from two petroleum industry based wastewater. A reduction rate of 84% was observed at the initial first 4 hours to about 90.5% after 96 hour experiment for plant P1 wastewater. While results from wastewater plant P2 indicated reduction rate of 97.2%, followed by 94.09% and lastly 56.8% respectively. The result affirmed the ability of this strain to optimally utilize the optimal conditional factors to grow and reduce mercury concentration overwhelmingly within a shortest time of less than 30 hours.

9 citations


Journal ArticleDOI
TL;DR: In this paper, a method of single drop microextraction (SDME) combined with high performance liquid chromatography (HPLC) with diode array detection (DAD) was studied for trace level enrichment as well as simultaneous determination of atrazine (ATZ) and its major degradation products such as desethylatrazine(DEA) and desisopropylatrazines (DIA) in environmental waters.
Abstract: In this work, a method of single drop microextraction (SDME) combined with high performance liquid chromatography (HPLC) with diode array detection (DAD) was studied for trace level enrichment as well as simultaneous determination of atrazine (ATZ) and its major degradation products such as desethylatrazine (DEA) and desisopropylatrazine (DIA) in environmental waters. The main factors influencing the extraction procedure including types and volume of extraction solvent, sample stirring rate, sample solution pH, extraction temperature, extraction time, and salting out effect were optimized. The method detection limits were as low as 0.01 for ATZ and 0.05 for both DIA and DEA, with coefficients of determination better than 0.998 within a linear range of 0.5-150 μg L-1. Under the optimal conditions, the proposed method was applied for the analysis of real water samples and good spiked recoveries in the range of 65.6%-96.3% with relative standard deviation of less than 5% were obtained. The results confirmed that the proposed procedure provides reliable precision, linearity and sensitivity and is very effective for analyzing the target compounds in environmental waters. Therefore, the developed SDME method coupled with HPLC-DAD was found to be simple, inexpensive, and environmentally benign sample pretreatment technique.

8 citations


Journal ArticleDOI
TL;DR: In this article, the effect of sample processing (non-extracted, ethanol extract and water extract) on H. sabdariffa composition was examined for the process of identification using Fourier Transform Infrared (FTIR).
Abstract: Hibiscus sabdariffa tea is a widely used medicinal beverage and a treatment for high blood pressure and high blood cholesterol in many parts of the world. Many studies on H. sabdariffa have been conducted including extraction and identification of main biocompounds. However, information on the effects of processing the plant is scarce. This is important as sample processing procedure influence the composition of the end product. Hence, the main objective of this present study was to examine the effect of sample processing (non-extracted, ethanol extract and water extract) on H. sabdariffa composition. Fourier Transform Infrared (FTIR) was used for the process of identification. The powdered sample of H. sabdariffa (FT34) was obtained from a local company in Peninsula Malaysia. A fresh sample obtained from the same company was processed in the Phytochemistry Laboratory, Institute for Medical Research and labelled as FT35. Sample and potassium bromide (KBr) were mixed (1:250) to form a 1-2 mm transparent disk under 9.80 psi in vacuum. The FTIR Spectra were recorded with 32 scans and 0.2 cms-1 OPD speed. Spectra of FT34 and FT35 raw samples indicated obvious differences in the range of 1500-1135 cm-1. The FT34 ethanol extract using trifluoroacetic acid (TFA) showed that the peak at 1629 cm-1 was the highest in the range of 1800-1500 cm-1, whereas for FT35, the highest peak was 1739 cm-1. The peak at 1071 cm-1 of FT35 was the only one compatible to standard dephinidin-3-O-sambubioside and cyanidin-3-Osambubioside which are used for qualification of sample content. In fact, both standards showed up as different chromatographs in thin layer chromatography. Water extract of FT35 showed a peak at 1676 cm-1 which was not detected in water extract spectrum of FT34, while the pattern of spectrum varied within the range of 1300-400 cm-1. Second derivative spectra enhanced the comparable base peaks of both sample and the target standards. There were five matched ethanol extract base peaks, indicating the macrofingerprint of H. sabdariffa. Two dimensional correlation spectrum of FT34 raw powder showed different correlation spot especially in the cluster of 1425 cm-1 to 1743 cm-1 compared with FT35. The three-stage infrared spectroscopy comprehensively analysed the holographic spectra and hierarchically characterized the integrated constituents involved.

Journal ArticleDOI
TL;DR: Endocannabinoids and related N-acylethanolamines (NAEs) are lipid mediators involved in a number of physiological and pathological mechanisms in peripheral tissues.
Abstract: Endocannabinoids and related N-acylethanolamines (NAEs) are lipid mediators involved in a number of physiological and pathological mechanisms in peripheral tissues. Microdialysis (MD) technique all ...

Journal ArticleDOI
TL;DR: In this article, reliable analytical methods for the detection and quantification of terpenes in these flows are presented, which have a common final step consisting of a TD-GC-MS/FID analysis using Tenax TA for the trapping of terphenes.
Abstract: Terpenes have been shown to be the dominant VOCs present in biogas mostly in plants where food wastes are digested. In particular, p-cymene and D-limonene have been reported to represent up to 90% of all VOCs in the biogas. A number of problems have been linked to terpenes in biogas plants, including odor problems, indoor air quality issues at workplaces and operational problems. In order to study the faith of terpenes, there is a need to develop robust analytical methods to quantify terpenes in all the flows at biogas plants including substrates, gas, and water samples. In this study, reliable analytical methods for the detection and quantification of terpenes in these flows are presented. The methods have a common final step consisting of a TD-GC-MS/FID analysis using Tenax TA for the trapping of terpenes. The methods were then applied to some samples taken at a biogas plant where food waste is digested. The results show that D-limonene was the dominant terpene in the substrate whereas p-cymene was dominant in biogas and process water.

Journal ArticleDOI
TL;DR: In this paper, the principles of two-dimensional gas and liquid chromatography (2DGC and 2DLC) and the theory accounting for the increase in separation resulting from a greater peak capacity than for the one-dimensional (1D) mode are discussed.
Abstract: This review covers the principles of two dimensional gas and liquid chromatography (2DGC and 2DLC) and briefly introduces the theory accounting for the increase in separation resulting from a greater peak capacity than for the one dimensional (1D) mode. The advance in the techniques from multi-dimensional to comprehensive chromatography is discussed. The more recent development of multi-dimensional chromatography ion mobility mass spectrometry receives a mention to highlight the added dimension of molecular size and shape (molecular collision cross section) as an enabling tool for increasing component separation and peak capacity. Although both the techniques of 2DGC and LC are described the focus is on the environmental and food applications of 2DGC, principally when coupled to mass spectrometry, with TOFMS and HRMS as prime examples.

Journal ArticleDOI
TL;DR: In this paper, the in-situ local corrosion behavior of scratched epoxy coated carbon steel is investigated in sat. Ca(OH)2 with varying concentration of Cl- ions by localized electrochemical impedance spectroscopy (LEIS).
Abstract: The in-situ local corrosion behavior of scratched epoxy coated carbon steel is investigated in sat. Ca(OH)2 with varying concentration of Cl- ions by localized electrochemical impedance spectroscopy (LEIS). The localized corrosion process and mechanism of coated steel (scratch area) is measured by LEIS plots and 3D topographic images. The LEIS responses measured at the defect are attributed to the pore impedance with defect in the highfrequency range and an interfacial corrosion reaction in the low-frequency range of corroding steel at the base of defect within 1-10 h immersion. The continuous decrease in |Z| at the scratch is due to the higher extent of dissolution of Fe with increase of Cl- ion concentration. However, the resistance values of coated steel in sat. Ca(OH)2 with each concentration of Cl- ions are not changed significantly with increase in immersion time from 1-10 h. On the other hand, LEIS Nyquist plots clearly showed that the measured impedance at high frequency is related to corrosion products formed at the defect which acts as anodic zones and the low frequency part are related to corroding of carbon steel with immersion of 1-5 days. 2D topographic images clearly showed that corrosion occurs at scratch and followed by coating degradation at scratch front as well as away from scratch due to cathodic reactions (reduction of O2) leads to coating delamination. No significant change in corrosion resistance is observed for 0 and 0.0085 M/L of Cl- ions containing solution for 5 days of immersion as well as 1-10 h immersion. This is due the formation of better passive film on the steel surface (defect) in which the competition between the aggressive Cl- ions and the inhibitive OH- ions determines the rate of corrosion. A significant decrease in corrosion resistance is observed with higher concentration of Cl- ions (0.17 and 0.51 M) due to the preferential adsorption of Cl- ions at the defect site.

Journal ArticleDOI
TL;DR: Five commonly employed surface coatings are compared, and it is found that MPEG is an effective surface coating for applications where long term stability is critical, and for separation experiments, where the channel is used shortly after coating, a silanized zwitterionic sultone has superior anti-fouling characteristics.
Abstract: Microfluidics-based separation of biomolecules has numerous applications, including fundamental characterization of biomolecules, sequencing of genomes for biological functions, biometric fingerprinting, and identification of pathogens and genetic diseases. One of the main drawbacks, however, for making microfluidic based separations more commercially viable is the non-specific adsorption of biomolecules at the channel walls during separations. Herein, we compare five commonly employed surface coatings, and evaluate their performance in terms of successful silanization of channel surface walls, long term stability, and antifouling performance, using BSA or IgG as model proteins. We compare adsorption of fluorescently-tagged proteins on glass slides with those confined within channels, showing similar behavior with static measurements, but differences when incorporating electrokinetic flow. Based on these data, we find that MPEG is an effective surface coating for applications where long term stability is critical. However, for separation experiments, where the channel is used shortly after coating, a silanized zwitterionic sultone has superior anti-fouling characteristics.

Journal ArticleDOI
TL;DR: For the first time, the N-glycosylation patterns of immunoglobulin G (IgGs) isolated from the serum of two varieties of knockout pigs were examined for the presence of potential glycan xenoantigens and compared to N-grecolylneuraminic acid patterns obtained for wild-type (WT) pig IgGs.
Abstract: For the first time, the N-glycosylation patterns of immunoglobulin G (IgGs) isolated from the serum of two varieties of knockout pigs (lacking N-glycolylneuraminic acid (Neu5Gc) and/or α 1,3 galactose) were examined for the presence of potential glycan xenoantigens and compared to N-glycosylation patterns obtained for wild-type (WT) pig IgGs. Glycopeptide analysis was chosen over glycan release, as protein-A eluates from pig serum may contain IgA and IgM as shown previously. The experiments focused on the analysis of tryptic glycopeptides EEQFNSTYR and AEQFNSTYR from IgGs, and excluded IgA and IgM, in which N-glycosylated peptides have different sequences and masses. WT pig IgG glycopeptides showed the presence of N-glycolylneuraminic acid (Neu5Gc) and absence of N-acetylneuraminic acid (Neu5Ac). Released glycans from the protein-A eluate, however, showed the presence of both types of sialic acids, allowing Neu5Ac to be attributed to IgA and/or IgM. The WT IgG samples also showed the presence of glycans that could by composition have been α-galactosylated, but treatments with α- and β-galactosidases produced inconclusive results as to the linkage nature of the terminal Gal residues. Single knockout (α-Gal transferase) pig IgG was shown to contain Neu5Gc residues, and there was a definite absence of α-Gal. Double knockout pigs (DKO for α-Gal transferase and cytidine monophosphate-A-acetylneuraminic acid hydroxylase (CMAH)) showed the definite absence of α-Gal and Neu5Gc. Instead of the latter, Neu5Ac residues were observed. Further investigation into the sialylation patterns of WT and DKO pig IgGs consisted of esterifying the glycopeptides to allow the detection and differentiation of α-2,3 and α-2,6 sialic acid-galactose linkages. Fucosylation levels were also compared between IgG species.

Journal ArticleDOI
Kudo Y, Kaminagayoshi A, Ikeda S, Yamada H, Katsuta S 
TL;DR: In this paper, the individual distribution constants (KD,A) for the extraction of NaA with 18-crown-6 ether (18C6) from water (w) into nitrobenzene (NB) were determined at 298 K. The plot of log Kex± versus Δφeq gave a positive correlation at (correlation coefficient)2 = 0.748.
Abstract: Extraction constants (Kex±) for the extraction of sodium salts (NaA) with 18-crown-6 ether (18C6) from water (w) into nitrobenzene (NB) were determined at 298 K, together with the determination of individual distribution constants (KD,A) of several pairing anions A−. The symbols Kex± and KD,A were defined as [NaL+]NB[A−]NB/([Na+][L]NB[A−]) at L = 18C6 and [A−]NB/[A−], respectively; the subscript “NB” shows the NB phase. Also, ion-pair formation constants for sodium 2,4-dinitrophenolate (NaDnp) and its ion pair complex with 18C6 in water were determined by potentiometry with a Na+-selective electrode. Standardized (S) KD,A values were briefly calculated from the following thermodynamic cycle: KD,A S = Kex±/KD,Na SKNaL,NB. Here, KD,Na S and KNaL,NB denote the standardized individual distribution-constant of Na+ into and a complex formation constant for NaL+ in the NB phase, respectively. Moreover, equilibrium potential differences (Δφeq) at the NB/w interface were estimated from the relation Δφeq = 0.05916log (KD,A S/KD,A) at 298 K. The Δφeq values of A− = F3CCO2 −, MnO4 −, ReO4 − and Dnp− were determined for comparison with the value of picrate ion. The plot of log Kex± versus Δφeq gave a positive correlation at (correlation coefficient)2 = 0.748.

Journal ArticleDOI
TL;DR: This paper presents a method of combining a cost-effective, home-deployable NIR system with a non-traditional trend-based data analysis to extract representative glucose levels from patients by taking multiple measurements over time with an unobtrusive, automatic, in-toilet urinalysis system.
Abstract: Many over-the-counter glucose measurement systems currently exist but are not widely used by nondiabetic consumers because of the inconvenience. There exists a need for new methods of conveniently detecting early stages of diabetic or prediabetic conditions rather than waiting for the disease to progress to the point that symptoms indicative of physiological damage are present and a user requests medical care. Near-infrared (NIR) spectroscopic urinalysis has shown some promise for use as an unobtrusive measurement system for glucose levels but has required expensive equipment. This paper presents a method of combining a cost-effective, home-deployable NIR system with a non-traditional trend-based data analysis to extract representative glucose levels from patients. By taking multiple measurements over time with an unobtrusive, automatic, in-toilet urinalysis system, limited accuracy samples from each patient can be averaged to obtain an improved accuracy trended value. Data trending is able to predict glucose levels with sufficient accuracy to be clinically relevant in the detection of chronically high glucose conditions. The bandwidth, or averaging window, of the filters can be varied to achieve a target accuracy level, even when the error of individual measurements is large and variable. Urine spectra can be captured from an athome or at-work toilet with a urine capture slot and NIR spectrometer. A new data reporting strategy is proposed for trended measurements, whereby filtered data is reported with a known and acceptable post-filter variance, rather than reporting individual sample measurements. This is in contrast to traditional methods of single-point clinical tests, which may require expensive equipment to achieve sufficient single-point accuracy, be obtrusive or inconvenient, available only on demand, or susceptible to outliers.

Journal ArticleDOI
TL;DR: In this article, structural, electronic, and magnetic characterization of two [CuII 2(thb)] (thb = N,N,N’,N'- tetrakis-{3-[(2- hydroxibenzyliden)-amine]propyl}-1,4-butanodiamine) crystalline phases (1a and 1b) are reported.
Abstract: Synthesis, structural, electronic, and magnetic characterization of two [CuII 2(thb)] (thb = N,N,N’,N’- tetrakis-{3-[(2- hydroxibenzyliden)-amine]propyl}-1,4-butanodiamine)]) crystalline phases (1a and 1b) are reported. Both, 1a and 1b, showed free radical scavenging activity, which was quantified by the DPPH free radical scavenging activity assay. 1b crystallized in a P21/c space group. In 1b each molecule contains two CuII-(hidroxibenzyliden) groups bonded in the extremes of the organic DAB-Am nucleus. The CuII-(hidroxibenzyliden) groups of each extreme, form 1D chains along of the b-axis. IR and UV-Vis spectra showed d-d transitions and νCu-O, νCu-N vibrations respectively, confirming the formation of the compound. 1H-NMR spectra of 1a and 1b showed similar spectra, being characteristics of paramagnetic compounds. Bulk magnetization of 1a and 1b from 2 K to 300 K showed paramagnetic behaviour. The best fit for the susceptibility data was obtained using Curie-Weiss and modified Curie-Weiss equations with θ and C values of θ1a/1b C-W = 0 ± 1K, C1a/1b C-W = 0.82/0.66 cm3 K mol-1, and θ1a/1b modified C-W = 0.6 ± 1K and C1a/1b modified C-W = 0.80/0.70 cm3 K mol-1. The X-band ESR spectra of 1a and 1b in solid samples showed a single and a rhombic signals, respectively, with g values around 2.1 at 77 K and 300 K, however, in CH2Cl2 solutions at 77 K the spectra were similar. The spectroscopic and magnetic results allowed us to conclude that 1a and 1b are two different crystalline phases which were proven to act as effective antioxidants showing both an IC50 = 16.5 μM, in contrast with Trolox, IC50 = 39.3 μM, normally used as a vitamin E analog and a strong antioxidant. Additionaly the DPPH free radical is scavened by reduction mechanism of CuII to CuI. The overall electronic, magnetic and structural information about 1a and 1b provide us some characteristics of this kind of transitional metal ionic coordination compounds.

Journal ArticleDOI
TL;DR: In this paper, a new highly selective optical sensor was prepared by deesterification of triacetyl cellulose transparent film and chemical immobilization of 1-acenaphthoquinone 1-thiosemicarbazone (L) on it.
Abstract: A new highly selective optical sensor was prepared by de-esterification of triacetyl cellulose transparent film and chemical immobilization of 1-acenaphthoquinone 1-thiosemicarbazone (L) on it. The absorbance variation of immobilized 1-acenaphthoquinone 1-thiosemicarbazone on hydrolyzed cellulose acetate film of upon addition of 1.5 × 10-5 mol L-1 aqueous solutions of Zn2+, Pb2+, K+, Cu2+, Ag+, Ni2 , Cd2+, Ca2+, CrO4 2-, Hg2+, Co2+, Mn2+, Cr3+, S2 O3 2-, Mg2+, Na+, Al3+, Tl+ and Fe3+ indicated a substantiality much larger variation for the Nickel ion in compare to other studied ions. Consequently, the new hydrazone derivative L possesses a high selectivity towards this metal ion. Influences of various experimental parameters on Ni2+ sensing, including the reaction time, the solution pH and the concentration of reagents were studied. A linear relationship was observed between the variance in membrane absorbance(∆A) at 337 nm and Ni2+ concentrations in a range from 5.01 × 10-10 to 2.04 × 10-5 mol L-1 with a detection limit (3σ) of 1.00 × 10-10 mol L-1. No significant interference from 100 times concentrations of a number of potentially interfering ions was detected for the nickel ion determination. The sensor showed a good durability and short response time with no evidence of reagent leaching. The optical sensor was successfully applied to the determination of nickel in real water samples.

Journal ArticleDOI
TL;DR: The analytical method including the pre-treatment and HPLC coupled to ICP-MS (HPLC-ICP-MS) techniques was developed and dynamic changes of intracellular metal concentration were demonstrated during cell differentiation from iPS cells to pancreatic β cells.
Abstract: Zinc, iron and copper are essential mineral nutrients for the human body to function. It is also known that there are biological processes which relate to metals in the body including cells. Therefore, understanding about intracellular metals is important for the regeneration medicine. Intracellular metals were thought to be able to be divided into two forms by function: i) protein binding metals and ii) labile metals. However, it is difficult to quantify the concentration in both intracellular metal forms. In this study, the analytical method including the pre-treatment and HPLC coupled to ICP-MS (HPLC-ICP-MS) techniques was developed. Our method is able to fractionate two forms of intracellular metals and quantify each concentration, simultaneously. Finally, the presented method was applied to analysis of several cell states. As a result, dynamic changes of intracellular metal concentration were demonstrated during cell differentiation from iPS cells to pancreatic β cells.

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TL;DR: In this paper, a cloud point extraction method was used for the preconcentration and extraction of cadmium (II) and zinc(II) ions in different environmental samples.
Abstract: In the present study, a cloud point extraction method was used for the preconcentration and extraction of cadmium (II) and zinc (II) ions in different environmental samples. The zinc and cadmium ions formed hydrophobic complexes with phenanthraquinone monophenyl thiosemicarbazone (PPT). These complexes were extracted using Triton X-114 nonionic surfactant. The surfactant-rich phase was diluted with acidified methanol. Then, the concentrations of the metal ions were determined by FAAS. The experimental factors controlling the process of separation are investigated e.g., pH, complexing agent concentration, surfactant's concentration, temperature, and incubation time. The present CPE-FAAS procedure has been used to preconcentrate and determine Cd(II) and Zn(II) metal ions in natural water samples, drug samples and certified reference materials. The LODs for cadmium(II) and zinc(II) ions were 0.38 and 1.85 μg/L, respectively with a preconcentration factor of 100. The recovery % of the extracted Cd(II) and Zn(II), is greater than 90% and the relative standard deviation(RSD,%) is less than 5%.

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TL;DR: The GLIE fluctuation-based measures demonstrated the ability to significantly distinguish cellular response to all six mediators, and identify subgroups of cells according to their response to mild hypothermia.
Abstract: Characteristics of spatiotemporal fluctuation of gray values at a single-pixel level within bright field, label free image of a cell are explored in a variety of physiological and mitochondrial dysfunction states. From these fluctuations, the gray level information entropy (GLIE) is calculated and its derivative measures such as standard deviation, autocorrelation and periodic aspect are analyzed. This is realized by a user-friendly combination of common bright field microscopy and a unique imaging dish, wherein cells are individually held untethered, each within a picoliter volume optical chamber in an array, which allows repeatable spatiotemporal observation before, during and after bio-manipulation in situ, at a single-cell resolution, while in a population. GLIE fluctuation measures were exploited to demonstrate the gradual dying process of serum-deprived cells. Furthermore, these measures were realized in the evaluation of cell response to Phorbol Myristic Acetate (PMA), triiodothyronine (T3) thyroid hormone and mild hypothermia, and three different mitochondrial inhibitors as well: rotenone, carbonyl cyanide m-chlorophenyl hydrazine (CCCP) and oligomycin. The GLIE fluctuation-based measures demonstrated the ability to (a) significantly distinguish cellular response to all six mediators, and (b) identify subgroups of cells according to their response to mild hypothermia. On the whole, employment of high contrast microscopy approaches, i.e., Phase Contrast (PC) and Differential Interference Contrast (DIC), for tracing cellular events via the spatiotemporal fluctuation measures, did not show noticeable advantages over simple Bright Field (BF) microscopy.

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TL;DR: In this article, the growth rate of self-nucleated calcium carbonate crystals on polysulfone (PSU) films was investigated with high resolution, time-lapse Raman imaging.
Abstract: The growth of single, self- nucleated calcium carbonate crystals on a polysulfone (PSU) film was investigated with high resolution, time lapse Raman imaging. The Raman images were acquired on the interface of the polymer with the crystal. The growth of crystals could thus be followed in time. PSU is a polymer that is used as a membrane material in water cleaning technology. The intensity of the Raman band at the position of 1086 cm-1, which is due to the symmetric stretching of the C-O bonds in the carbonate group of calcite was used to translate the number of CO3 2- ions in a crystal to the growth in time. The growth rate of single crystals of calcium carbonate on a surface was obtained from successive Raman images. We are presenting for the first time time-lapse Raman images of single crystal growth as a direct method to determine a crystal growth rate on an industrially relevant membrane material, like polysulfone.

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Abstract: The present work has been undertaken with the aim to formulate hair growth gel formulation containing extracts of Hibiscus rosa sinensis flower 1%, Eclipta alba whole plant 1% and Solanum nigrum plant berries 0.5% which are preferably used in case of Alopecia, i.e., baldness pattern as an effective herbal therapy showing 5 α-reductase inhibitory activity. The formulated gel was evaluated for parameters such as pH which was found to be 6.68, viscosity 4731 cps, spreadability 11.05 (g-cm/sec) whereas consistent homogeneity was found with no skin irritation. Simultaneous quantification of bioactive markers was done by HPTLC. Quercetin, β-sitosterol and linoleic acid were selected as bioactive markers for quantification of Hibiscus rosa sinensis flower, Eclipta alba whole plant and Solanum nigrum plant berries extract respectively in the formulation. The aforementioned markers have 5 α-reductase inhibitory activity. β-sitosterol, quercetin and linoleic acid was found to be 0.1377, 0.120 and 0.379% w/w respectively in the formulated gel.

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TL;DR: In this paper, a column with high-polar stationary liquid phases based on pyridinium ionic liquids was used for GC × GC separation of bio-oil and product of coal pyrolysis.
Abstract: The work describes the application of columns with high-polar stationary liquid phases based on pyridinium ionic liquids for GC × GC separation of bio-oil and product of coal pyrolysis. By using inverse combination columns- the first ionic liquid column, the second is HP-5 the good separation results have been obtained. In the analysis of coal pyrolysis products, the suggested approach provides a much better resolution between components in comparison with a less polar first-dimension column (ZB-WAX). The good selectivity for peaks of phenols is observed, and the group of phenols is well detached and separated from the group of diaromatics. For bio-oil also good separation picture was obtained, the groups of phenols and guaiacol derivatives are distinguished with good resolution of substances within each group.

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TL;DR: In this article, a thin-layer chromatographic (HPTLC) method for quantification of topiramate in human breast milk was developed using liquid-liquid extraction with n-hexane and methanol as extraction solvents, fluorescence activation with ninhidrine (1% ethanolic solution) and chlorpromazine as internal standard.
Abstract: A thin-layer chromatographic (HPTLC) method for quantification of topiramate in human breast milk was developed using liquid –liquid extraction with n-hexane and methanol as extraction solvents, fluorescence activation with ninhidrine (1% ethanolic solution) and chlorpromazine as internal standard. Thin-layer chromatographic separation was performed on precoated silica gel F 254 HPTLC plates using a mixture of toluene: ethanol (25:10, v/v), as mobile phase. Densitometric detection was done at 326 nm. The method was validated for linearity, precision, selectivity, LOD and LOQ, and accuracy. Linear calibration curves in the range of 0.30 to 50.00 µg/mL showed correlation coefficient of 0.991. The intra-assay and inter-assay precision, expressed as the relative standard deviation (RSD), were in the range of 3.04% - 3.14% (n=3) and 1.81%-4.10% (n=9), respectively. The limit of detection was 0.24 µg/mL, and the limit of quantification was 0.30 µg/mL Accuracy, calculated as percentage recovery, was between 101.65% and 109.51%, with a RSD not higher than 0.41%. Topiramate is well resolved from others antiepileptic drugs and from the internal standard (Rs=5.20). In conclusion, the method is precise, accurate, reproducible and selective for the analysis of topiramate in human breast milk.

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TL;DR: In this article, polar molecule niacin is considered as a model drug to evaluate the synergistic approach and the results indicate that extraction procedure plays a crucial role to control matrix effect but to get the best result LC have to be coupled with mass spectrometer with proper ion source.
Abstract: In this research work we have tried to emphasis that the synergistic approach is required wherein during method development sample processing and instrument i.e., mass spectrometershall be evaluated in synchronized manner to get the best possible combination of processing technique and instrument model to get a method with no or minimal matrix effect. To perform this research work polar molecule niacin is considered as a model drug to evaluate the synergistic approach. Plasma was treated with three different conventional sample preparation procedures (PPT, LLE and SPE) and samples processed with the three methodology were then analyzed on three different instrument models of AB Sciex i.e., API-3000, API-3200, API-4000. Except for type of sample processing technique and instrument model, rest of the parameters like aliquot volume, internal standard working solution volume and chromatographic conditions were kept constant to avoid contribution of these factors due to these variables. Samples were analyzed using Inertsil® CN-3 as an analytical column and mobile phase consist of acetonitrile - solution-1(0.002% formic acid in water, v/v) in the ratio of 70:30, v/v. Result evidently showed that matrix effect was minimized through SPE technique over LLE technique and behavior of the co-elute matrix also changed significantly with ion-source design of the mass spectrometer. Consequently, the development result clearly showed that matrix effect was nullified by samples prepared by SPE technique and analyzed on API-3000. Results obtained from API- 3000 and API-4000 models were also comparable in terms of matrix effect. API-3000 in combination with solid phase extraction procedure was selected to further validate the method as API-4000 showed charge competition of internal standard. Overall, the results indicate that extraction procedure plays a crucial role to control matrix effect but to get the best result LC have to be coupled with mass spectrometer with proper ion source.

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TL;DR: A new analytical method by simple liquid chromatographyultraviolet spectrometry method was developed and validated for the simultaneous quantification of three analgesic drugs (morphine, ropivacaine and ziconotide) and can be considered as a stability indicating method.
Abstract: Pain is often considered as the most feared symptom amongst individuals living with cancer. It can arrive at any stage during the course of the illness. In 15% to 20% of patients, conventional analgesic therapy either fails to relieve pain or induces adverse effects. Use of analgesic admixture has been recommended by the most recent consensus conferences. Several studies found evidence of synergistic effects of intrathecal analgesic admixtures, most notably these containing ziconotide, morphine and ropivacaine, administering by a fully implantable pumps. The refills were prepared under a laminar airflow hood under strictly aseptic conditions, by the hospital pharmacist. This group of drugs that commonly used can be at the origin of errors inducing adverse effects in patients. In order to evaluate the accuracy of compounding of intrathecal admixtures, a new analytical method by simple liquid chromatography ultraviolet spectrometry method was developed and validated for the simultaneous quantification of three analgesic drugs (morphine, ropivacaine and ziconotide). The method was validated according to the recommendation of the US Food and Drug Administration (FDA). The method was linear, between 0.1 to 4 μg/ml for ziconotide, 0.1 to 10 mg/ ml for ropivacaine and 0.1 to 32 mg/ml for morphine. Forced degradation of ziconotide by acidic conditions allowed formation and detection of degradation products by the analytical method. This method can be considered as a stability indicating method. It is also part of a continuing quality process designed to improve accuracy of preparation.