Somewhere in the course of the last two decades a word which conveniently describes our society today, and of this century, has almost dropped out of popular usage. Technology - which Webster defines as “industrial science; the science of systematic knowledge of industrial arts”. Our entire sociological structure is geared to technological advancement - not merely to maintenance of the status quo.It was estimated earlier that the approximately 250 men and women in these sessions represent some 1400 years of pure education, largely in mathematics, electronics and other areas directly related to computers - which, in themselves, represent a separate, unique industrial art. Add to these years the aggregate years of experience in the field and the mean of 6 years per man may well double - in a new, young unique industrial art. You represent here, Ladies and Gentlemen, the nucleus of one of the most significant single elements contributing to technological advancement in the world today - the element of knowledgeable computer applications.

New approaches

Recent advances in stir-bar sorptive extraction: Coatings, technical improvements, and applications

Stir bar sorptive extraction and its application.

There is a need for fast and reliable quality and authenticity control tools of pharmaceutical ingredients. Among others, hormone containing drugs and foods are subject to scrutiny. In this study, terahertz (THz) spectroscopy and THz imaging are applied for the first time to analyze melatonin and its pharmaceutical product Circadin. Melatonin is a hormone found naturally in the human body, which is responsible for the regulation of sleep-wake cycles. In the THz frequency region between 1.5 THz and 4.5 THz, characteristic melatonin spectral features at 3.21 THz, and a weaker one at 4.20 THz, are observed allowing for a quantitative analysis within the final products. Spectroscopic THz imaging of different concentrations of Circadin and melatonin as an active pharmaceutical ingredient in prepared pellets is also performed, which permits spatial recognition of these different substances. These results indicate that THz spectroscopy and imaging can be an indispensable tool, complementing Raman and Fourier transform infrared spectroscopies, in order to provide quality control of dietary supplements and other pharmaceutical products.

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Spectroscopic Analysis of Melatonin in the Terahertz Frequency Range.

In situ mid-infrared (MIR) spectroscopy in liquids is an emerging field for the analysis of functional surfaces and chemical reactions. Different basic geometries exist for in situ MIR spectroscopy in milliliter (mL) and microfluidic flow cells, such as attenuated total reflection (ATR), simple reflection, transmission and fiber waveguides. After a general introduction of linear optical in situ MIR techniques, the methodology of ATR, ellipsometric and microfluidic applications in single-reflection geometries is presented. Selected examples focusing on thin layers relevant to optical, electronical, polymer, biomedical, sensing and silicon technology are discussed. The development of an optofluidic platform translates IR spectroscopy to the world of micro- and nanofluidics. With the implementation of SEIRA (surface enhanced infrared absorption) interfaces, the sensitivity of optofluidic analyses of biomolecules can be improved significantly. A large variety of enhancement surfaces ranging from tailored nanostructures to metal-island film substrates are promising for this purpose. Meanwhile, time-resolved studies, such as sub-monolayer formation of organic molecules in nL volumes, become available in microscopic or laser-based set-ups. With the adaption of modern brilliant IR sources, such as tunable and broadband IR lasers as well as frequency comb sources, possible applications of far-field IR spectroscopy in in situ sensing with high lateral (sub-mm) and time (sub-s) resolution are considerably extended.

https://iopscience.iop.org/article/10.1088/1361-648X/ab8523/pdf

Sensing and structure analysis by in situ IR spectroscopy: from mL flow cells to microfluidic applications.

A novel nanosilica/polydimethylsiloxane (SiO2/PDMS) coated stirring bar was adopted in the sorption extraction (SBSE) of phenols in water, and the high performance liquid chromatography-fourier transform infrared spectroscopy (HPLC-FTIR) was subsequently used to determination of phenol concentration. The SiO2/PDMS coating was prepared by sol-gel method and characterized with respect to morphology and specific surface area. The results of field-emission scanning electron microscope (FE-SEM) and N2 adsorption-desorption as well as phenol adsorption experiments denoted that SiO2/PDMS has larger surface area and better adsorption capacity than commercial PDMS. The extraction efficiency of phenol with SiO2/PDMS coated stirring bar was optimized in terms of ion strength, flow rate of phenol-involved influent, type of desorption solvent and desorption time. More than 75% of phenol desorption efficiency could be kept even after 50 cycles of extraction, indicating the high stability of the SiO2/PDMS coated stirring bar. Approximately 0.16 mg/L 2, 5-dimethylphenol (2, 5-DMP), which was 34-fold more toxic than phenol, was detected in water through HPLC-FTIR. However, 2, 5-DMP could be oxidized to 5-methy-2-hydroxy benzaldehyde after disinfection in drinking water treatment process. Therefore, the proposed method of SiO2/PDMS-SBSE-HPLC-FTIR is successfully applied in the analysis of phenols isomers in aqueous environment.

/pdf/determination-of-phenols-isomers-in-water-by-novel-3a2o4burp7.pdf

Determination of Phenols Isomers in Water by Novel Nanosilica/Polydimethylsiloxane-Coated Stirring Bar Combined with High Performance Liquid Chromatography-Fourier Transform Infrared Spectroscopy

The components for connecting high-performance liquid chromatography (HPLC) with Fourier-transform infrared spectroscopy (FTIR) were investigated to determine estrogen in the water environment, including heating for atomization, solvent removal, sample deposition, drive control, spectrum collection, chip swap, cleaning and drying. Results showed that when the atomization temperature was increased to 388 K, the interference of mobile phase components (methanol, H2O, acetonitrile, and NaH2PO4) were completely removed in the IR measurement of estrogen, with 0.999 of similarity between IR spectra obtained after separation and corresponding to the standard IR spectra. In experiments with varying HPLC injection volumes, high similarity for IR spectra was obtained at 20 ul injection volume at 0.01 mg/L BPA while a useful IR spectrum for 10 ng/L BPA was obtained at 80 ul injection volume. In addition, estrogen concentrations in the natural water samples were calculated semi-quantitatively from the peak intensities of IR spectrum in the mid-infrared region.

/pdf/separation-and-determination-of-estrogen-in-the-water-58zxupd2w5.pdf

Separation and determination of estrogen in the water environment by high performance liquid chromatography-fourier transform infrared spectroscopy

α-D-1,6-glucan from Castanea mollissima Blume alleviates dextran sulfate sodium-induced colitis in vivo.

Traditional Chinese fermented shrimp paste is popular with consumers for its unique seafood flavor and fermented aroma. However, different heating methods exerted various flavors, which directly affect consumer choice and the industrialization of shrimp paste. In this study, the effect of four heating methods (steaming, frying, microwaving, and infrared) on volatile components of shrimp paste were compared by headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC–MS), gas chromatography–ion mobility spectrometry (GC-IMS) and chemometrics. Results showed that 96 volatile components were identified; The volatile components such as pentanal, ethyl acetate, dimethyl disulfide, and propanal were the characteristic volatile components that could be distinguished between different heating methods. The concentration of phenols and alcohols decreased, and the concentration of ketones and aldehydes increased after heating. The effect of microwave heating on volatile components is closer to that of steaming and frying, while infrared heating had the most significant impact on volatile components of shrimp paste. In addition, steaming, frying, microwaving, and infrared heating improve the aroma quality of shrimp paste by promoting fat oxidation, protein degradation, the Strecker pathway, and the escape of sulfur-containing compounds. Therefore, our results can provide theoretical support for improving shrimp paste quality and consumer choice. 

New insights from flavoromics on different heating methods of traditional fermented shrimp paste: The volatile components and metabolic pathways

Traditional Chinese fermented shrimp paste is a national geographical indication product with a distinctly regional flavor. The great commercial value and highly appreciated aroma urgently require establishing reliable methods to define the origin of shrimp paste and dissect the aroma essence. Therefore, in this study, flavoromics, chemometrics, and data augmented machine learning were performed to analyze shrimp paste from different regions of Bohai Bay, China. The results showed that shrimp paste contained several volatile compounds, including sulfur-containing compounds, nitrogen-containing compounds, aldehydes, and alcohols. In addition, chemometric and flavor association networks indicated that higher salt content produces some volatile compounds, such as 2-heptanone and phenylethanol. Furthermore, the prominent fruitiness and fermented aromas were associated with some key aroma substances, such as (E)-2-octenal and phenylethanol. Finally, a classification model for the origin identification of shrimp paste was developed. The results showed that seven trained machine learning models, including random forest (RF), support vector machine (SVM), and artificial neural network (ANN), were able to accurately (100%) identify the origin of shrimp paste. In summary, this study provides a theoretical support and application basis for identifying the origin and protection of the characteristic geographical flavor of shrimp paste. • First analysis of shrimp paste from different regions of China using machine learning. • OPLS-DA reveals the relationship of fermentation information and volatile components. • The visual flavor network was constructed based on key aroma substances. • RF and ANN are reliable ways to identify the origin of shrimp paste. 

The analysis of volatile compounds through flavoromics and machine learning to identify the origin of traditional Chinese fermented shrimp paste from different regions

Lin Liu

Papers

Determination of Phenols Isomers in Water by Novel Nanosilica/Polydimethylsiloxane-Coated Stirring Bar Combined with High Performance Liquid Chromatography-Fourier Transform Infrared Spectroscopy

Separation and determination of estrogen in the water environment by high performance liquid chromatography-fourier transform infrared spectroscopy

α-D-1,6-glucan from Castanea mollissima Blume alleviates dextran sulfate sodium-induced colitis in vivo.

New insights from flavoromics on different heating methods of traditional fermented shrimp paste: The volatile components and metabolic pathways

The analysis of volatile compounds through flavoromics and machine learning to identify the origin of traditional Chinese fermented shrimp paste from different regions