Carrier Solution Research Articles

Preliminary investigation into suitable techniques to measure the chemical yield of radionuclides in thermal neutron irradiated samples at AWE (Atomic Weapons Establishment)

Radiochemical separation methods are required for the accurate measurement of radionuclides in complex matrices. To be able to quantify the results after the separation of radionuclides, known amounts of either radioactive tracers or inactive carrier solutions are added at the start of the separation. The added isotopes/elements are then measured at the end of the analysis to calculate the chemical yield for the element or isotope. The chemical yield data is applied to the counting data of the analytes of interest to produce quantified results. Recently, changes have been made to the techniques used to measure chemical yields at the Atomic Weapons Establishment for samples containing fission products. Preliminary development work using wavelength dispersive X-ray fluorescence and inductively coupled plasma–atomic emission spectrometry is discussed, including a comparison of results and evaluation of measurement uncertainty. The use of the techniques to measure fission products in a thermal neutron irradiated uranium sample is described.

Influence of Adding Surfactants to an Analyte Solution on Separation Performance in Open-tubular Capillary Chromatography Based on the Tube Radial Distribution of Ternary Mixed Carrier Solvents

Abstract An open-tubular capillary chromatography system has been developed using a ternary mixed solvent mixture, i.e., water–hydrophilic/hydrophobic organic solvent mixture as a carrier solution. In this study, the influence of adding surfactants to an analyte solution on separation performance was examined in a chromatographic system using a fused-silica capillary tube (75 µm inner diameter and 100 cm effective length) and a ternary mixture of water–acetonitrile–ethyl acetate (3:8:4 volume ratio) carrier solution. Sodium dodecyl sulfate (anionic), ethylhexadecyldimethylammonium bromide (cationic), and Triton X-100 (nonionic) were used as surfactants. Model analytes, 1-naphthol and 2,6-naphthalenedisulfonic acid, were separated in this order by adding the anionic and nonionic surfactants. These surfactants in the analyte solution greatly improved the separation performance (theoretical plate numbers for 2,6-naphthalenedisulfonic acid; >10000) compared with the same separation performed in the absence of surfactants. On the other hand, the analytes were not separated at all using a cationic surfactant.

Distribution, Elimination, and Toxicity of Silver Nanoparticles and Silver Ions in Rats after 28-Day Oral Exposure

We report the results of a 28-day oral exposure study in rats, exposed to <20 nm noncoated, or <15 nm PVP-coated silver nanoparticles ([Ag] = 90 mg/kg body weight (bw)), or AgNO(3) ([Ag] = 9 mg/kg bw), or carrier solution only. Dissection was performed at day 29, and after a wash-out period of 1 or 8 weeks. Silver was present in all examined organs with the highest levels in the liver and spleen for all silver treatments. Silver concentrations in the organs were highly correlated to the amount of Ag(+) in the silver nanoparticle suspension, indicating that mainly Ag(+), and to a much lesser extent silver nanoparticles, passed the intestines in the silver nanoparticle exposed rats. In all groups silver was cleared from most organs after 8 weeks postdosing, but remarkably not from the brain and testis. Using single particle inductively coupled plasma mass spectrometry, silver nanoparticles were detected in silver nanoparticle exposed rats, but, remarkably also in AgNO(3) exposed rats, hereby demonstrating the formation of nanoparticles from Ag(+)in vivo that are probably composed of silver salts. Biochemical markers and antibody levels in blood, lymphocyte proliferation and cytokine release, and NK-cell activity did not reveal hepatotoxicity or immunotoxicity of the silver exposure. In conclusion, oral exposure to silver nanoparticles appears to be very similar to exposure to silver salts. However, the consequences of in vivo formation of silver nanoparticles, and of the long retention of silver in brain and testis should be considered in a risk assessment of silver nanoparticles.

The loss of OSA‐modified starch emulsifier property during the high‐pressure homogeniser and encapsulation of multi‐flavour bergamot oil by spray drying

SummaryThe encapsulation of bergamot oil by spray drying was investigated by using octenyl succinylated waxy maize starch as wall material and bergamot oil as core. The bergamot oil is majorly composed of d‐limonene, linalool and linalyl acetate. High‐speed and high‐pressure homogenisers were used as major tools of emulsification process. The results indicated that some chemical functional groups were lost during the high‐pressure homogenisation. Moreover, larger emulsion droplet size (5–10 μm) was observed when emulsion passed through high‐pressure homogeniser. Meanwhile, the saturation of carrier solution before preparing the emulsion was also important to produce the encapsulated flavour powder by spray drying. The optimal value of air inlet temperature at 160 °C to give the highest flavour retention and the lowest surface oil content was observed. Furthermore, the retention of linalool after spray drying was higher than 100%. The transformation of each flavour might occur.

STUDY OF OUTER PHASES IN CAPILLARY CHROMATOGRAPHY BASED ON TUBE RADIAL DISTRIBUTION OF CARRIER SOLVENTS UNDER LAMINAR FLOW CONDITIONS

A capillary chromatography system that consists of an open capillary tube composed of fused–silica, polyethylene, and poly(tetrafluoroethylene), and a water–hydrophilic/hydrophobic organic mixture carrier solution has been developed. We call this system the tube radial distribution chromatography (TRDC) system. In this study, variance, theoretical plate number, and height equivalent to a theoretical plate for a solute peak in the chromatogram were expressed using theoretical equations derived from the differential equation for the secondary moment of a solute. The relationship between the thickness and diffusion coefficient in the outer phase in the capillary tube in the TRDC system was calculated from theoretical equations using numerical values for the analytical conditions and experimental data. The outer phase that featured the TRDC system had a larger diffusion coefficient and a larger thickness than those of the stationary phase in standard liquid chromatography. We confirmed the separation performance obtained on the basis of the tube radial distribution of the carrier solvents under laminar flow conditions in the TRDC system by considering the inner and outer phase generation in the capillary tube.

The Study on Dipentene Hydrogenation Catalyst

In this paper, we prepared Dipentene Hydrogenation Catalyst by impregnating, with activated alumina as catalyst carrier and nickel nitrate solution as soaking liquid. The objective of this study was to investigate the influences of the amount of nickel loading, calcination temperature and hydrogen reduction temperature on catalyst activity. The results show that the optimum parameters are: 21% of nickel loading, the calcination temperature of 550-650 °C, the hydrogen reduction temperature of 325-350 °C. The purity of p-menthane prepared under the conditions was more than 97 %, reaching special class standards.

Elution Behavior of Lambda-DNA with Ternary Mixed Carrier Solvents in an Open-Tubular Capillary under Laminar Flow Conditions

An open-tubular capillary chromatography was developed based on the tube radial distribution of the ternary mixed carrier solvents that generated the inner and outer phases under laminar flow conditions. This is called "tube radial distribution chromatography" (TRDC). In this report, the elution behavior of lambda-DNA (48502 bp) as a biopolymer was examined by the TRDC system. The ternary mixture of water-acetonitrile-ethyl acetate, 15:3:2 or 3:8:4 volume ratio, as a carrier solution was fed into the capillary tube made of polytetrafluoroethylene (PTFE) or fused-silica. The mixture of hydrophobic 1-naphthol and hydrophilic lambda-DNA was subjected to the TRDC system using the water-rich carrier solution. Lambda-DNA and 1-naphthol were distributed between the inner and outer phases due to their hydrophilic and hydrophobic nature, and then eluted in this order, undergoing chromatographic separation. The mixture of hydrophilic 2,6-naphthalenedisulfonic acid and hydrophobic lambda-DNA that was treated with surfactants was also examined with the organic solvent-rich carrier solution. The modified hydrophobic DNA and 2,6-naphthalenedisulfonic acid were distributed and eluted in this order due to their nature.

A very sensitive flow-injection spectrophotometric determination method for iron (II) and total iron using 2′, 3, 4′, 5, 7-pentahydroxyflavone

In this study, an ultra-sensitive and highly selective, rapid flow-injection spectrophotometric method for the determination of iron (II) and total iron has been proposed. The method was based on the reaction between iron (II) and 2', 3, 4', 5, 7-pentahydroxyflavone in slightly acidic solution with a strong absorption at 415nm. The carrier solution used was 1 × 10(-5)M 2', 3, 4', 5, 7-pentahydroxyflavone in 0.1M HAc/Ac(-) buffer solution at pH4.5. Parameters that affect simultaneously the determination of iron (II) and interfering ions were tested. The relative standard deviation for the determination of 50μgL(-1) iron (II) was 0.85% (n = 10), and the limit of detection (blank signal plus three times the standard deviation of the blank) was 3μgL(-1), both based on injection volumes of 20μL. The method has been successfully applied to the determination of iron (II) and total iron in water samples and ore samples. The method was verified by analysing a certified reference material Zn/Al/Cu 43XZ3F.

Biomolecule Analyses in an Open-Tubular Capillary Chromatography Using Ternary Mixed Carrier Solvents with Chemiluminescence Detection

We examined the elution behavior of isoluminol isothiocyanate (ILITC)-labeled biomolecules (α-amino acids, peptides, and proteins) in an open-tubular capillary chromatography system using an untreated fused-silica capillary tube and a water-acetonitrile-ethyl acetate mixture carrier solution. Such an open-tubular capillary chromatography is called "tube radial distribution chromatography (TRDC)" for convenience. A mixture of ILITC and ILITC-labeled biomolecules was analyzed using TRDC with chemiluminescence detection that provided simple instrument without a light source and complex optical devises. The ILITC and the labeled twenty α-amino acids were separated, in this order or the reverse order, or not separated with an organic solvent-rich and water-rich carrier solution. Their elution behavior was considered to be of hydrophilic or hydrophobic nature of ILITC and the labeled α-amino acids. The ILITC and the labeled protein, alcohol dehydrogenase and bovine serum albumin, were separated in this order with an organic solvent-rich carrier solution, while they were eluted in the reverse order with a water-rich carrier solution, based on the TRDC separation performance. The TRDC system worked with the untreated open-tubular capillary tube not using any specific capillary tubes, such as coated, packed, or monolithic.

1689 THE EFFECT OF VACUUM THERAPY ON PEYRONIES' DISEASE RAT MODEL

You have accessJournal of UrologySexual Function/Dysfunction/Andrology: Peyronie's Disease/Surgical Therapy I1 Apr 20121689 THE EFFECT OF VACUUM THERAPY ON PEYRONIES' DISEASE RAT MODEL Haocheng Lin and Run Wang Haocheng LinHaocheng Lin Houston, TX More articles by this author and Run WangRun Wang Houston, TX More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2012.02.1584AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Vacuum therapy has recently been used by some investigators as a therapy for peyronie's disease (PD). However there is no scientific evidence supporting its use at present time. This study was designed to use our rat-specific vacuum erection device (VED) in rat PD model to evaluate the effect of vacuum device therapy on PD. METHODS PD animal model was established following intra-tunical injection of Transforming growth factor beta-1 (TGFβ1) and Thrombojet carrier solution on one side of cavernosal body. Adult Sprgue-Dawley rats were randomly assigned into three groups: Group1: Control-saline was injected into tunica albuginea (TA). Group 2: PD model-TGFβ1 and Thrombojet were injected into TA. Group 3: PD model with VED treatment-TGFβ1 and Thrombojet were injected into TA followed by VED therapy after the PD model was successfully established. VED was applied under isoflurane inhalation, 5 min twice daily with a 1 min interval, Monday–Friday. Penile curvature angle was measured weekly. After 4 weeks treatment, intracavernosal pressure (ICP) and mean arterial pressure (MAP) are measured under cavernous nerve stimulation, the penis was collected and processed for immunohistochemistry of TGFβ1, Inducible nitric oxide synthase (iNOS) and Terminal deoxynucleotidyl transferase dUTP nick end labeling assay (TUNEL). RESULTS 1. Histology stain and penile deformity confirmed PD rat model was successfully established. 2.VED therapy reduced the penile curvature angle in PD rat model. 3. VED therapy improved erectile function in PD rat model as demonstrated by ICP/MAP ratio. 4. VED therapy decreased TGFβ1 and iNOS expression level. 5. VED therapy decreased cell apoptotic in corpus cavernosum of PD rats. CONCLUSIONS Our study demonstrated that VED therapy was effective to reverse PD progression and preserve erectile function. The underlying mechanisms might be mechanic distraction, anti-apoptosis and anti-fibrosis. © 2012 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 187Issue 4SApril 2012Page: e682 Advertisement Copyright & Permissions© 2012 by American Urological Association Education and Research, Inc.MetricsAuthor Information Haocheng Lin Houston, TX More articles by this author Run Wang Houston, TX More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Highly sensitive sequential injection determination of p-aminophenol in paracetamol formulations with 18-molybdodiphosphate heteropoly anion based on elimination of Schlieren effect

A highly sensitive, precise and automated method using sequential injection analysis to assay quantitatively low levels of the p-aminophenol (PAP) in paracetamol formulations has been developed. A solution containing PAP and paracetamol is injected into an acetate buffer carrier stream and merged on-line with 18-molybdodiphosphate heteropoly complex reagent to form a specific blue derivative that is subsequently detected spectrophotometrically at 820nm. The procedure has been optimized mainly with respect to measurement sensitivity. It is based on the leveling off of the refraction indices of the liquids mixed in the flow system by the careful matching of the refractive index of the reagent solution with that of the carrier and sample solutions. Amount as low as 0.5μmolL−1 of PAP, which corresponds to the 0.001% of PAP in paracetamol tablets, can be reliably determined using the proposed method, which is clearly below the specification limits recommended for PAP determination in paracetamol drug and tablet formulations (50ppm or 0.005% (w/w)). The developed method was successfully applied to the analysis of paracetamol formulations spiked with PAP and determination of PAP content in Rapidol tablets past their expiration date both by proposed SIA and reference HPLC methods.

Flow injection determination of carboxylate, phosphate, and sulfhydryl compounds using metal exchange complexation

The determination of carboxylate, phosphorous, and sulfhydryl compounds has been studied using flow injection by measuring the decrease in absorbance of the Fe(III)–salicylate complex due to preferential ligand interaction with ferric ion. Targeted compounds include polycarboxylates such as sodium citrate, sodium oxalate, and EDTA, anionic phosphorous compounds such as sodium monofluoroorthophosphate, sodium trimetaphosphate, and sodium hexametaphosphate, and sulfhydryl compounds such as cysteine, glutathione, and captopril. Initial flow injection optimization has focused on citrate based on its ability to replace salicylate ion in the Fe(III)–salicylate complex causing a decrease in absorbance at 525nm proportional to the citrate concentration. Two flow injection analysis methods are developed. In the first method, offline reaction flow injection, sodium citrate dissolved in 100μmolL−1 Fe–salicylate is injected in a carrier solution of 100μmolL−1 Fe–salicylate. The decrease in peak area is linear over a range of 1.36–109μmolL−1 using a flow rate of 1mLmin−1 and an injection volume of 100μL. The effect of pH on the Fe–salicylate complex absorbance is studied from 1 to 3.5; pH 3 shows both a high and stable complex absorbance in the visible range which provided important potential selectivity over UV detection. The limit of detection is found to be less than 57nmolL−1 depending on the Fe(III)–salicylate concentration used. The second method is reverse flow injection using the sample as a flowing stream in which 3mmolL−1 Fe(III)–salicylate is injected and the decrease in the response with increased sample concentration was monitored. The commercially available pharmaceutical product (Citroma)® is used to assess the accuracy and precision of the two proposed methods as compared to a reference method.

Tentative Comparison of Tube Radial Distribution Chromatography and CZE

Tube radical distribution chromatography (TRDC) uses an untreated open tubular capillary tube and a ternary mixture of solvents (water and hydrophilic/hydrophobic organic solvents) as a carrier solution. A model analyte mixture comprising 1-naphthol, 1-naphthoic acid, 1-naphthalenesulfonic acid, 2,6-naphthalenedisulfonic acid, and 1,3,6-naphthalenetrisulfonic acid was examined by the TRDC and capillary zone electrophoresis (CZE) systems that comprised mainly a capillary tube and a detector. In the TRDC system the elution order of analytes could be changed by altering the component ratios of the solvents, whereas in the CZE system the elution order was changed by altering the electroosmotic flow direction. The experimental data obtained provide clues about the features and utility of TRDC as a new separation method.

In vivo MR imaging of pulmonary perfusion and gas exchange in rats via continuous extracorporeal infusion of hyperpolarized 129Xe.

BackgroundHyperpolarized (HP) 129Xe magnetic resonance imaging (MRI) permits high resolution, regional visualization of pulmonary ventilation. Additionally, its reasonably high solubility (>10%) and large chemical shift range (>200 ppm) in tissues allow HP 129Xe to serve as a regional probe of pulmonary perfusion and gas transport, when introduced directly into the vasculature. In earlier work, vascular delivery was accomplished in rats by first dissolving HP 129Xe in a biologically compatible carrier solution, injecting the solution into the vasculature, and then detecting HP 129Xe as it emerged into the alveolar airspaces. Although easily implemented, this approach was constrained by the tolerable injection volume and the duration of the HP 129Xe signal.Methods and Principal FindingsHere, we overcome the volume and temporal constraints imposed by injection, by using hydrophobic, microporous, gas-exchange membranes to directly and continuously infuse 129Xe into the arterial blood of live rats with an extracorporeal (EC) circuit. The resulting gas-phase 129Xe signal is sufficient to generate diffusive gas exchange- and pulmonary perfusion-dependent, 3D MR images with a nominal resolution of 2×2×2 mm3. We also show that the 129Xe signal dynamics during EC infusion are well described by an analytical model that incorporates both mass transport into the blood and longitudinal relaxation.ConclusionsExtracorporeal infusion of HP 129Xe enables rapid, 3D MR imaging of rat lungs and, when combined with ventilation imaging, will permit spatially resolved studies of the ventilation-perfusion ratio in small animals. Moreover, EC infusion should allow 129Xe to be delivered elsewhere in the body and make possible functional and molecular imaging approaches that are currently not feasible using inhaled HP 129Xe.

Effects of Tube Materials on Capillary Chromatography Based on Tube Radial Distribution of Ternary Mixture Carrier Solvents under Laminar Flow Conditions

A capillary chromatography system was developed using an open capillary tube and a ternary solvents carrier solution of water-hydrophilic/hydrophobic organic solvent mixture. The chromatography is called a tube radial distribution chromatography (TRDC) system. The TRDC system works without applying high voltages or using specific columns, such as monolithic and packed columns. In this study, the effects of tube materials on separation performance were examined in the TRDC system, by using poly(tetrafluoroethylene) (PTFE; 100–400 μm inner diameter), polyethylene (PE; 200 μm inner diameter), and copolymer of (tetrafluoroethylene–perfluoroalcoxyethylene) (PTFE–PFAE; 100 μm inner diameter) capillary tubes. An analyte solution of 2,6-naphthalenedisulfonic acid and 1-naphthol as a model was subjected to the system with a water–acetonitrile–ethyl acetate carrier solution; 15:3:2 volume ratio (water-rich carrier) and 3:8:4 volume ratio (organic solvent-rich carrier). The flow rates were adjusted to be 0.5 μL min−1 for PTFE and PTFE–PFAE tubes as well as 2.0 μL min−1 for PE tube under laminar flow conditions. These analytes in the solution were separated in this order with the water-rich carrier solution with baseline separation in the three capillary tubes, while they were eluted in the reverse order or not separated with the organic solvent-rich carrier solution. The effects of tube temperature on separation were also examined with the water-rich carrier solution; the best resolutions were observed at 0 °C of the tube temperature. The obtained results were compared with those of fused-silica capillary tube and discussed.

Influence of spray pyrolysis deposition parameters on the optoelectronic properties of WO3 thin films

The electrochromic (EC) properties of tungsten oxide (WO3), such as coloration efficiency, cyclic durability and reversibility strongly depend on the structural and morphological properties, which are influenced by the deposition method and parameters.This paper presents the steps for optimizing the deposition parameters (substrate temperature, air flow pressure and precursor solution molarity) for improving the optical and electrical properties of WO3 thin films for EC applications. WO3 thin films were deposited by spray pyrolysis using tungsten hexachloride (WCl6) dissolved in ethanol as precursor solution. The EC properties of optimized films were tested in two different electrolytes (H2SO4 1M and acetic acid/sodium acetate buffer with pH=4) and changes in structure, composition and morphology of the films after coloration/bleaching cycles were discussed.The deposition temperature, carrier gas pressure and solution molarity were optimized at 250°C, 120kPa and 0.14M respectively. Under these condition a dense, uniform film, with homogenous distribution of particles, good adhesion to the substrate, low roughness (9.02nm), high transparency (>70% in the 500–1100nm range) and conductivity was obtained. Transmission modulation is higher for the sample cycled in H2SO4 1M (64% at 630nm) compared to that cycled in the buffer (21% at 630nm), whereas opposite results were obtained for coloration efficiencies 28cm2C−1 (at 630nm) and 35cm2C−1 (at 630nm), respectively. Changes in surface chemistry and morphology of the optimized sample were observed after cycling in H2SO4.

Biosensor for on-line fluorescent detection of trifluoroperazine based on genetically modified calmodulin

This paper describes the development of a novel on-line biosensor based on a fluorescently labeled human calmodulin (CaM), hCaM M124C-mBBr, immobilized on controlled-pore glass (CPG), for the analysis of trifluoroperazine (TFP); a phenothiazine drug in human urine samples. The device was automated by packing hCaM M124C-mBBr-CPG in a continuous-flow microcell connected to a monitoring system, composed of a bifurcated optical fiber coupled to a spectrofluorometer. Operating parameters of the on-line biosensor (flow rate, sample injection volume, and carrier solution and buffer pH) were studied and optimized. Under the optimal conditions, the biosensor provides a detection and a quantification limit of 0.24 and 0.52 μg mL(-1), respectively, and a dynamic range from 0.52 to 61.05 μg mL(-1) TFP (n = 5, correlation coefficient 0.998). The response time (t(100)) was shorter than 42 s (recovery time <4.5 min) and reproducibility and repeatability of the TFP measurements, within the linear response range, were lower than 1.4 and 2.7%, respectively. The device was successfully applied to the analysis of TFP in spiked human urine samples with recoveries ranging between 97 and 101% and with RSDs lower than 5.9%.

Flow injection analysis of sulphide based on its photoelectrocatalytic oxidation at poly-methylene blue modified glassy carbon electrode

A new approach for photoelectrocatalytic determination of sulphide in a flow injection analysis (FIA) system was studied using a poly-methylene blue modified glassy carbon electrode (poly-MB/GCE). Results from electrochemical measurements have revealed that poly-MB/GCE is capable of signalling electrocatalytic and photoelectrocatalytic activity towards sulphide oxidation. When the surface of poly-MB/GCE was irradiated with a light source (250W Halogen lamp), the electrocatalytic current increased substantially. A homemade flow electrochemical cell with a suitable transparent window for the irradiation of the electrode surface was used to perform the photoelectrocatalytic determination of sulphide in FIA system. The currents obtained from the photoamperometric measurements in the FIA system at optimum conditions (carrier solution: pH 9.0 Britton Robinson buffer solution containing 0.1M KCl; flow rate: 1.3mLmin−1; transmission tubing length: 10cm; injection volume: 100μL; and constant applied potential: +150mV vs. Ag/AgCl/KClsat) were linearly correlated with the sulphide concentration. The calibration curves were obtained for sulphide concentrations in a range of 0.5–500μM. The detection limits were found to be 0.27 and 0.15μM for amperometric and photoamperometric methods, respectively. The proposed method was successfully applied to different wastewaters such as municipal sewage or tannery wastewater. Finally, results from the sulphide measurements by poly-MB/GCE were in good agreement with those attained using spectrophotometric method.

Separation of dansyl-dl-amino acids by open tubular capillary chromatography based on tube radial distribution phenomenon of the ternary mixed carrier solvents

Separation of enantiomers, dansyl-DL-amino acids, was carried out by open-tubular capillary chromatography based on the tube radial distribution of the carrier solvents. An untreated poly(tetrafluoroethylene) capillary tube (100 μm inner diameter and 90 cm effective length) as a separation column and a water–acetonitrile–ethyl acetate mixture containing cyclodextrin as a carrier solution were used in the chromatography. An analyte solution of dansyl-DL-amino acids, such as dansyl-DL-methionine, was injected into the capillary tube by a gravity method. The analyte solution was subsequently delivered through the capillary tube with the carrier solution by a microsyringe pump. The ternary mixed carrier solution (water-rich carrier solution) was radially distributed in the capillary tube based on the tube radial distribution phenomenon, causing the formation of inner (water-rich) and outer (organic solvent-rich) phases. The outer or capillary wall phase acted as a pseudo-stationary phase in the chromatography. The analytes were separated through the capillary tube with on-capillary detection by an absorption or a fluorescence detector. The D-enantiomer and the L-enantiomer were eluted in this order with a baseline separation. The separation mechanism of the enantiomers in the open-tubular capillary using cyclodextrin was discussed.

Microfluidic Behavior of Ternary Mixed Carrier Solvents Based on the Tube Radial Distribution in Triple-Branched Microchannels in a Microchip

Microfluidic behavior of ternary mixed carrier solvents of water-acetonitrile-ethyl acetate (2:3:1 volume ratio) was examined by use of a microchip incorporating microchannels in which one wide channel was separated into three narrow channels, i.e., triple-branched microchannels. When the ternary carrier solution containing the fluorescent dyes, hydrophobic perylene (blue) and relatively hydrophilic Eosin Y (green), was fed into the wide channel under laminar flow conditions, the carrier solvent molecules or fluorescence dyes were radially distributed in the channel, forming inner (organic solvent-rich major; blue) and outer (water-rich minor; green) phases in the wide channel. And then, in the narrow channels, perylene molecules mostly appeared to flow through the center narrow channel and Eosin Y, which is distributed in the outer phases in the wide channel, flowed through the both side narrow channels. A metal ion, Cu(II) as a model, dissolved in the ternary mixed carrier solution was also examined. The Cu(II) showed fluidic behavior, transferring from the homogeneous carrier solution to the water-rich solution in the side narrow channels through the triple-branched microchannels.