Showing papers in "Analytical Sciences in 1999"

Rapid Determination of Anionic Surfactants by Improved Spectrophotometric Method Using Methylene Blue

Abstract: A rapid and simple method for the determination of anionic surfactants in tap water has been developed. The official analytical method in Japan for the determination of anionic surfactants in tap water requires tedious procedures and requires large amounts of chloroform as the extract solvent; it was greatly improved by the present spectrophotometric method using Methylene Blue. Our present method requires only one half of sample (50 ml), one tenth of the extraction solvent (chloroform=5 ml), and one sixth of the analytical time compared with the official analytical method.

Determination of Arsenic(III) and Total Arsenic(III,V) in Water Samples by Resin Suspension Graphite Furnace Atomic Absorption Spectrometry

Abstract: A preconcentration method of arsenic(III) using ammonium pyrrolidinedithiocarbamate (APDC) and a finely divided anion-exchange resin is described for the determination by graphite-furnace atomic absorption spectrometry (GFAAS). The method is based on the extraction of the As(III)-APDC complex on the resin phase at pH 1.2, separation of the resin particles by filtration, dispersion of them in 1.0 ml of 0.1 mol l-1 nitric acid containing 50 µg of nickel(II), and introduction of the suspension to a graphite furnace. The detection limit of arsenic in a 150-ml sample aliquot was 1.0 ng (6.7 ppt), based on three times the standard deviation of the blank. Total inorganic arsenic(III,V) was extracted similarly after the reduction of As(V) to As(III) with sodium thiosulfate. The interfering ions, such as Cu(II), Pb(II) and Sn(II), could be removed by extraction as the respective APDC complexes at pH 5, where neither As(III) nor As(V) were extracted. Arsenic(III) and total As(III,V) in the filtrate were then extracted at pH 1.2 in the absence or presence of sodium thiosulfate, respectively. The proposed method was applied to the determination of As(III) and total inorganic As(III,V) in hot spring water, seawater, river and tap water samples.

Integration of Flow Injection Analysis and Zeptomole-Level Detection of the Fe(II)-o-Phenanthroline Complex

Abstract: Microchannels having a 150×100 µm cross section were fabricated in a quartz glass chip as a component in an integrated flow injection analysis (FIA) system. They were put to use for flow, mixing, reaction, and detection. The reaction system was a chelating reaction of divalent iron ion with o-phenanthroline (o-phen), and a photothermal microscope was applied for the ultra-sensitive detection of the non-fluorescent reaction product. Nano liter levels of solutions were introduced and transported by capillary action and mixed by molecular diffusion. Zeptomole levels of the reaction product were detected quantitatively. This was the first demonstration of an on-chip chemical determination device which integrates the primitive FIA system without using electroosmotic liquid control or fluorometric determination.

Highly Sensitive Electrochemiluminescence Immunoassay Using the Ruthenium Chelate-Labeled Antibody Bound on the Magnetic Micro Beads.

Abstract: The newer electrochemiluminescence (ECL) immunoassay system was established by using both an antibody coated on paramagnetic micro-beads (Capt-MB) as a carrier of the immunoassay and an antibody labeled with ruthenium(II) tris-bipyridine-NHS (Ru-Ab). The ECL excitations were designed to be generated upon the surface of the working electrode which collected the reacted Capt-MB by magnetic force. As a model of the immunoassay, the reaction between alpha-fetoprotein (AFP) and anti-AFP antibodies was used in accordance with the so-called sandwich method, where the sandwich conformation of AFP-(Ru-Ab) was made on the surface of the Capt-MB. The ECL immunoassay system revealed the following results: a) the ECL signal intensity was obtained in proportion to the AFP concentration of each specimen; b) the dynamic range of this ECL immunoassay system was extended to 10000 times of magnitude in the 2-step assay; and c) the detection sensitivity reached to the level of 5 pg/ml in the AFP concentration after 15 min in the 1-step immunoassay.

Flow-Injection Spectrophotometric Determination of Nitrite and Nitrate in Biological Samples

Abstract: Nitrite and nitrate in biological samples can act as an indicator of nitric oxide generated in vivo and have attracted a lot of attention as a messenger of diverse physiological processes. For the determination of such nitrogen oxides, a simple and sensitive flow-injection method coupled with a successful pretreatment method was developed. Nitrite and nitrate in sample solution were injected into a carrier solution containing EDTA and ammonium buffer, and flowed into the copperized cadmium (Cd/Cu) reduction column installed on-line. Here the nitrate was reduced to nitrite, and then nitrite was determined spectrophotometrically on the basis of a diazotization/coupling reaction. The detection limits for nitrite and nitrate were 5×10-8 M, and the sampling rate was about 40 samples per hour for nitrate determination. The biological samples, such as serum, plasma and cell culture medium, were deproteinized using a batchwise NaOH-ZnSO4 method before FIA measurement. The NaOH-ZnSO4 deproteinization method was very effective in term of the recovery of nitrate and the maintenance of the reduction efficiency of the Cd/Cu column. The relative standard deviations were 2.1 - 3.1%, and the recoveries were 95 - 100% for the determination of nitrite and nitrate in serum samples through the whole procedure. In the case of cell culture medium, the proposed deproteinization was especially effective for removing the interfering amino acids containing sulfur atom by using the reaction between Zn2+ in deproteinization agent and sulfur atom in analytical substances.

Separation and Detection of Bile Acid 24-Glucuronides in Human Urine by Liquid Chromatography Combined with Electrospray Ionization Mass Spectrometry

Abstract: A method for the separation and determination of bile acid 24-glucuronides using liquid chromatography (LC)/electro-spray ionization (ESI)-mass spectrometry (MS) has been developed. In the ESI mode, 24-glucuronides were characterized by an intense deprotonated molecule [M-H]- with a fragment ion [M-H-176]- formed by elimination of the glucuronic acid moiety. The ratio of these negative ions was significantly influenced by the orifice-1 and the ring lens voltages. Bile acid 24-glucuronides in human urine were extracted with an OASIS HLB cartridge and then subjected to the LC/ESI-MS analysis employing an 18O-labeled internal standard. The simultaneous separation was attained on a Develosil ODS-HG-5 column using 20 mM ammonium acetate (pH 6.0)-acetonitrile (3:1→3:2, v/v, 35 min) in a linear gradient elution mode, where the 24-glucuronides were monitored with a characteristic negative ion [M-H]-; the limit of detection was 10 fmol. This newly developed method was applied to the quantitation of bile acid 24-glucuronides in human urine with satisfactory selectivity and reliability.

Flow-Injection Assay of Superoxide Dismutase Based on the Reduction of Highly Water-Soluble Tetrazolium

Abstract: A flow-injection analysis (FIA) for superoxide dismutase (SOD) activity was developed based on the use of tetrazolium salt, WST-1 (4-[3-(4-iodophenyl)-2-(4-nitrophenyl)-2H-5-tetrazolio]-1,3-benzene disulfonate sodium salt) and an enzyme reactor packed with Sepharose 4B on which xanthine oxidase (XO) and catalase were co-immobilized. WST-1 is highly water-soluble, and no adhesion of the reduced form to the FIA line was observed during continuous operation for 3 months. As optimized conditions, a sample (9 vol) was mixed with a reagent solution (1 vol) containing 3 mM hypoxanthine and 2 mM WST-1, and the mixed solution (20 μl) was injected into a carrier stream of 50 mM carbonate buffer (pH 10.2) at a flow rate of 0.4 ml/min. Under the conditions, the concentration of the SOD preparation giving 50% inhibition (IC50) was 2.7 μg/ml and the sampling frequency was 30 samples/h. When the SOD activity in erythrocytes of rats was determined by the present FIA method, the values were linearly related to those obtained by the conventional nitroblue tetrazolium (NBT) assay (r=0.975; n=18). The enzyme reactor was stable for at least 200 repetitive injections.

In Situ Observation of Electrochemical Formation and Degradation Processes of Polyaniline by Fourier-Transform Infrared Spectroscopy

Abstract: The electrochemical polymerization of aniline on a platinum electrode in aqueous HClO4 and H2SO4 solutions has been studied by means of in situ Fourier-transform infrared (FTIR) reflection spectroscopy. The spectra, taken at early stage of the polymerization in both solutions, exhibited the absorption characteristic of polyaniline (PAn) in an emeraldine state, even at a highly positive potential (≥+0.7 V vs. Ag/AgCl (saturated KCl)). Polymer growth in H2SO4 was accompanied by an increase in the molar ratio of [HSO4-]/[SO42-], indicating that the protons generated during the oxidation of aniline react with SO42- to afford HSO4-, and that polymer growth is facilitated. In contrast, such proton-scavenging behavior was not observed in a HClO4 solution, and the growth of PAn was suppressed owing to the accumulation of protons. Under the condition that aniline was extremely consumed, the produced PAn was subjected to oxidative degradation, which was competitive with the growth process of PAn. The major degradation species was identified to be p-benzoquinone.

Enrichment of Metal-APDC Complexes on Admicelle-Coated Alumina for Water Analysis

Abstract: Aggregates of sodium dodecyl sulfate (SDS) formed on alumina particles were employed as enrichment vehicles of hydrophobic metal-chelates from water samples. To a 50 cm3 suspension of 1.5 g of purified alumina was added 100 mg of SDS; the mixture was then acidified to pH 2, where the anionic surfactant was strongly adsorbed on positively charged alumina surfaces to form admicelles. Nanogram quantities of heavy metals (Co, Ni, Cu, Cd and Pb) in water were com-plexed with APDC at pH 2 - 6 and quantitatively incorporated in the admicelles. A nearly complete desorption was achieved for those metals (except for Co) in 4 mol dm-3 nitric acid with the aid of ultrasonic irradiation. A multielement determination was performed by ICP-MS. The reliability of the proposed method was evaluated by analyzing a certified reference seawater sample.

Fluorometric Determination of Hydrogen Peroxide in Natural Water Samples by Flow Injection Analysis with a Reaction Column of Peroxidase Immobilized onto Chitosan Beads

Abstract: It was found that a FIA system with an immobilized enzyme reaction column could be utilized for the determinations of hydrogen peroxide in some water samples, such as rain water and tap water. A column was packed with chitosan beads immobilizing horseradish peroxidase. Under the recommended conditions, it took 5 min for each assay, and the detection limit, which was defined as a signal-to-noise ratio of 3, was 3.0 ng dm-3 of hydrogen peroxide. The relative standard deviation at 1.0 mg dm-3 of hydrogen peroxide was 1.5% (n=20). There was no interference from some coexisting sub-stances having a low oxidation-reduction ability or not; therefore, a standard addition method could be applied to rain water and tap water samples. From such results, it has become clear that the proposed FIA system can be applied to the determination of hydrogen peroxide in water samples, and that the system is suitable for routine analysis in environmental observations.

Chemiluminescence determination of thiourea using tris(2,2'-bipyridyl)ruthenium(II)-KMnO4 system

Abstract: The emission produced by thiourea in oxidation by permanganate in acidic solution in the presence of Ru(bipy)32+ is used to determine 1.8×10-8 to 1.8×10-6 mol/l thiourea. The limit of detection is 1.0×10-8 mol/l and the relative standard deviation is 1.1% for a 1×10-5 mol/l thiourea solution (n=10). The method was applied satisfactorily to the determination of thiourea.

In situ preconcentration method for trace dissolved sulfide in environmental water samples using solid-phase extraction followed by spectrophotometric determination

Abstract: A simple and rapid method for the in situ preconcentration of trace dissolved sulfide in environmental water samples has been developed based on solid-phase extraction using Sep-Pak C18 cartridges. Dissolved sulfide in water samples, which was taken into a graduated syringe to prevent the oxidation of sulfide by air, was reacted with N,N-dimethyl-p-phenylene-diamine sulfate and iron(III) chloride to be converted into Methylene Blue immediately after sample collection. The formed Methylene Blue was adsorbed on Sep-Pak C18, which was stable on Sep-Pak C18 for at least 30 d. The adsorbed Methylene Blue was eluted with a mixture of methanol and 0.01 M hydrochloric acid. The color intensity due to the Methylene Blue was measured at 659 nm. The proposed method is applicable to brackish and sea water samples as well as freshwater.

Sub-Zeptomole Detection in a Microfabricated Glass Channel by Thermal-Lens Microscopy

Abstract: A thermal-lens microscope which we developed was applied to an ultramicro quantity determination of a dye in an aqueous solution filling a microchannel (150 μm wide and 100 μm deep) fabricated in a quartz glass substrate. The detection volume, which corresponded to the confocal volume, was estimated to be 1.3 fl. The detection limit of the dye molecules was 160 ymol, and the calibration line showed good linearity in the sub-zmol-to-zmol region. This detection sensitivity is equivalent to that of laser-induced fluorometry. The thermal-lens signal measured in the microchannel was more stable than that measured in a liquid micro space between a slide glass and a cover glass, which was much wider than the microchannel. This may have been due to a suppression of convection in the microchannel. The thermal lens method can be applied to non-fluorescent chemical species, and is thus very suitable detection method for integrated chemistry systems.

Quantitative Determination of Pregnenolone 3-Sulfate in Rat Brains Using Liquid Chromatography/ Electrospray Ionization-Mass Spectrometry

Abstract: A method for the quantitative determination of pregnenolone 3-sulfate (PS) in rat brains has been developed using liquid chromatography/electrospray ionization-mass spectrometry (LC/ESI-MS). The PS fraction was obtained from the rat brain homogenate by solid-phase extraction and ion-exchange chromatography. After the derivatization with 4-(N,N-dimethylaminosulfonyl)-7-hydrazino-2,1,3-benzoxadiazole, PS was determined using LC/ESI-tandem MS along with the standard addition method. This method was applied to the quantitative determination of this steroid in the brains of Wistar strain rats, most of which showed a much lower amount than that previously reported.

Determination of 210 Pb and 210 Po in Environmental Samples by Alpha Ray Spectrometry Using an Extraction Chromatographic Resin

Abstract: A determination method using an extraction chromatographic resin (EiChroM Sr.Spec™) has been developed for 210 Pb and 210 Po in environmental samples by alpha ray spectrometry. 210 Pb and 210 Po were coprecipitated simultaneously on CuS at pH 4.0 - 5.5. These nuclides were then adsorbed on a Sr.Spec™ resin column (0.79×4.0 cm) in 4 M HCl. The 210 Pb and 210 Po on the resin were eluted with 8 M HCl and 6 M HNO3, respectively. 210 Po was determined by alpha-ray spectrometry after plating on a stainless-steel disk. 210 Pb was determined as 210 Po produced from 210 Pb decay. The method was applied to soil (IAEA-326) and sediments (NIST-4354, IAEA-135, IAEA-368) standard reference materials, and the results agreed with their recommended values. The chemical yield of Po ranged from 56 to 99% and the yield of Pb was 95%. The detection limits of 210 Pb and 210 Po were 0.6 mBq/sample at a counting time of 70000 s.

Chemiluminescence Determination of Tetracyclines Using a Tris(2,2′-bipyridine)ruthenium(II) and Potassium Permanganate System

Abstract: A chemiluminescence method for the determination of tetracyclines was developed. The method is based on an enhancement of tetracyclines upon the chemiluminescence light emission of tris(2,2′-bipyridine)ruthenium(II). In a sulfuric acid medium, chemiluminescence light emission is generated upon continuous oxidation of tris(2,2′-bipyridine)ruthenium(II) by potassium permanganate, catalyzed by Mn(II). The light-emission intensity is enhanced when the tetracyclines are also present in the reaction system. Under the optimum conditions, the calibration curves are linear over the range 1.0×10-7 - 1.0×10-5 g/ml for tetracycline, 4.0×10-8 - 1.0×10-5 g/ml for chlortetracycline and 1.0×10-7 - 1.0×10-5 g/ml for oxytetracycline. The limits of detection (S/N=3) are 2.0×10-8 g/ml for tetracycline, 1.0×10-8 g/ml for chlortetracycline and 2.0×10-8 g/ml for oxytetracycline. The proposed method was used to determine tetracyclines in pharmaceutical formulations with good results.

Experimental Optimization of Selective Hydrazine Detection in Flow Injection Analysis Using a Carbon Paste Electrode Modified with Copper Porphyrin Occluded into Zeolite Cavity

Abstract: A carbon paste electrode modified with copper porphyrin occluded into zeolite cavity was developed for sensing hydrazine in flow system. The sensor presented a high sensitivity and selectivity for hydrazine concentration in the flow system. The flow system was optimized by factorial design considering a two level, three factor factorial design (the factors were applied potential, sampling volume and flow rate). The sensitivity and analytical frequency were considered as the most important parameters for the system. The best condition for the system was sampling volume of 50 μl, applied potential of 270 mV vs. SCE and a flow rate of 1 ml min-1. In this optimized condition, the electrode can improve its stability, sensitivity and selectivity. The operational range was between 5 up to 60 μmol l-1, adjusted by the equation Y=1.9(±0.1)+0.20(±0.01)[hydrazine]-0.0014(±0.0001)[hydrazine]2, with a correlation coefficient of 0.9995 for n=8. The analytical frequency was about 70 determinations per hour and the system was stable for at least two months in continuous use.

Sub-Attomole Molecule Detection in a Single Biological Cell in-vitro by Thermal Lens Microscopy

Abstract: We have developed a novel thermal lens microscopy coupled with an optical microscope, and presently applied it to the ultratrace molecule detection in a single biological cell (mouse hybridoma) in-vitro. The determination results obtained for individual cells were calibrated by the average values determined by absorption spectrophotometry. The determination limit of the thermal lens microscope, defined as twice the standard deviation of the calibration curve, was 37.8 amol/cell, which was more than one order smaller than that of a fluorescence microscope under our experimental conditions. This superiority should come from escaping light scattering by a cell membrane and by cytoplasm, which is inevitable in fluorescence spectrometry. The absolute determination limit of the thermal lens microscopy was calculated down to sub-attomole level. In addition, the method is more widely applicable, even to non-fluorescent samples without chemical preparation, and therefore, the thermal lens microscope has proved to be very useful in directly quantifying ultratrace chemical species in a single biological cell in-vitro.

Preparation and Characterization of Zirconia-Silica and Zirconia-Magnesia Supports for Normal-Phase Liquid Chromatography

Abstract: Two kinds of zirconia-containing mixed oxide gels (zirconia-silica and zirconia-magnesia) were synthesized as rigid microparticulates by means of the sol-gel process. The physical and chemical characteristics, such as the particle-size distribution, the specific surface area, the crystal structures and the acid-base properties of the oxides, were examined. The molar ratio of Si/Zr and Mg/Zr on the surface of the two mixed oxides was estimated, respectively, by means of electron spectroscopy. The chromatographic performance of zirconia-silica and zirconia-magnesia was compared to that of silica and zirconia with pyridine and phenol as solutes. The separations of nitroanilines and toluidines were achieved on the two mixed oxides under normal-phase liquid chromatographic conditions, respectively.

Determination of Trace Metals in Geological Samples by Atomic Absorption Spectrophotometry after Preconcentration by Aspergillus niger Immobilized on Sepiolite

Abstract: A method for the determination of Cu, Zn, Fe, Ni and Cd in geological samples by flame atomic absorption spectrophotometry (FAAS) after preconcentrating by Aspergillus niger immobilized on sepiolite has been developed. The column adsorption method was used for the preconcentration studies. Effects of pH, amount of adsorbent, elution solution, flow rate and interfering ions on the recovery of the analytes have been investigated. Recoveries of Cu, Zn, Fe, Ni and Cd on Aspergillus niger immobilized sepiolite were 98.01±0.06%, 98.8±0.5%, 98.0±0.4%, 96.4±0.8% and 94.8±0.6% at 95% confidence level, respectively. The breakthrough capacity of the adsorbent was found as 0.093, 0.078, 0.067, 0.085 and 0.102 mmol/g for Cu, Zn, Fe, Ni and Cd, respectively. The proposed method was applied to the determination of trace metals in geological samples, such as AGV-1, JG-1a and Wismuterz II. Trace metals have been determined with about 5% relative error.

The Identification of Chemical Species of Silica in Sodium Hydroxide, Potassium Hydroxide and Sodium Chloride Solutions by FAB-MS

Abstract: The chemical species produced by dissolving silica in sodium hydroxide (NaOH) and potassium hydroxide (KOH) solutions were measured by FAB-MS (fast atom bombardment mass spectrometry). As a system for a comparison, silica gel was dissolved in a sodium chloride (NaCl) solution. The pH of the NaCl solution was controlled and a NaCl solution containing silica was measured by FAB-MS. NaOH and KOH solutions contain the monomer (Si(OH)3O-; m/z=95), monomer-Na+ and K+ complexes (Si(OH)2O2Na-; m/z=117, Si(OH)2O2K-; m/z=133), dimer (Si2(OH)5O2-; m/z=173), dimer-Na+ and K+ complexes (Si2(OH)4O3Na-; m/z=195, Si2(OH)4O2K-; m/z=211), cyclic tetramer (Si4(OH)7O5-; m/z=311), linear tetramer (Si4(OH)9O4-; m/z=329) and cyclic tetramer-Na+ and K+ complexes (Si4(OH)6O6Na-; m/z=333, Si4(OH)6O6K-; m/z=349). The results for the monomer, dimer and cyclic tetramer silica observed in our study are consistent with the results of a 29-Si NMR measurement. The relative-intensity ratios of these species vary with the pH. It is notable that the production rate of the dimer is superior to those of other chemical species, such as the monomer, monomer-Na+, cyclic tetramer and linear tetramer in NaOH solution. In a KOH solution, the dimer concentration increases initially and becomes constant when the cyclic tetramer concentration starts to increase with increasing pH. In a NaCl solution, monomer-Na+ complexes (Si(OH)2O2Na-; m/z=117, Si(OH)O3Na2-; m/z=139), dimer (Si2(OH)5O2-; m/z=173), dimer-Na+ complexes (Si2(OH)4O3Na-; m/z=195, Si2(OH)3O4Na2-; m/z=217, Si2(OH)2O5Na3-; m/z=239), trimer (Si3(OH)7O3-; m/z=251), trimer-Na+ complexes (Si3(OH)6O4Na-; m/z=273, (Si3(OH)5O5Na2-; m/z=295), cyclic tetramer (Si4(OH)7O5-; m/z=311), and cyclic tetramer-Na+ complexes (Si4(OH)6O6Na-; m/z=333, Si4(OH)5O7Na2-; m/z=355) of silica are observed. NaCl solution contains monomer-Na+ (m/z=117), dimer (m/z=173), dimer-Na+ (m/z=195), cyclic tetramer (m/z=311) and cyclic tetramer-Na+ (m/z=333) complexes, which are in chemical equilibrium, and their relative intensity ratios are almost constant regardless of the pH of the solution.

Sensitive and Simple Determination of Diclofenac Sodium by Use of a Continuous Flow-Injection Procedure with Solid-Phase Spectroscopic Detection

Abstract: A flow-through sensor for the determination of diclofenac sodium was developed, based on retention of the analyte on a Sephadex QAE A-25 anion-exchange resin packed in a flow-cell of 1 mm of optical path length, and monitoring of its intrinsic absorbance by UV-spectrophotometry at 281 nm. Diclofenac could be determined in the concentration ranges 2.0 - 40.0, 1.0 - 22.0 and 0.5 - 14.0 µg ml-1 with RSD (%) ranging from 1.05 to 1.53 for sample volumes of 300, 600 and 1200 µl, respectively. The proposed sensor was satisfactorily applied to the rapid determination of diclofenac in commercial pharmaceutical preparations and in semi-synthetic pharmaceuticals containing diclofenac and paracetamol.

Spectrophotometric Method for the Determination of Ritodrine Hydrochloride and Amoxicillin

Abstract: A rapid and sensitive spectrophotometric method is described for the determination of ritodrine hydrochloride (RTH) and amoxicillin (AMX) in both pure and dosage forms. The proposed method uses 3-methyl benzothiazolin-2-one hydrazone as a chromogenic reagent. A mixture of aqueous solutions of the drug and reagent is treated with ammonium cerium(IV) sulfate in an acidic medium to yield pink-colored species. These species exhibit maximum absorption at 520 nm for RTH and at 490 nm for AMX with a molar absorptivity of 2.35×104 and 1.27×104 l mol-1 cm-1 for RTH and AMX, respective-ly. The optimum reaction conditions and other analytical parameters are evaluated. The influence of the substrates commonly employed as excipients with these drugs have been studied. The proposed method was applied to the determination of these drugs in pharmaceutical formulations. The results have demonstrated that the method is equally accurate and reproducible as the official methods.

Fluorescent Chemo-Sensor for Organic Guests Based on Regioselectively Modified 6A,6B-, 6A,6C-, and 6A,6D-Bisdansylglycine-Modified β-Cyclodextrins

Abstract: Flexible hosts, 6A,6B-, 6A,6C-, and 6A,6D-bis-dansylglycine-modified β-cyclodextrins (β-1, β-2, and β-3, respectively) have been synthesized as a fluorescent chemo-sensor for organic guests including terpenoids and bile acids. Molecular sensing abilities obtained as fluorescence spectral changes of these hosts on accommodation of guests were almost twice those of γ-analogues. The sequence of binding ability of β-analogues is β-2> β-1> β-3. The molecular recognition behaviors of dansyl moieties of the title compounds are studied by induced circular dichroism (ICD), fluorescence, and absorption spectra without and with the guest. These spectral variations suggest that the appended moieties move out far from the cavity of β-cyclodextrin when host-guest complexation occurs.