Biomedical subjects

Shifen Mou

Publications and source records attributed to Shifen Mou.

22 records · Page 2Linked to original sources

PubMed2002

Separation methods for taurine analysis in biological samples.

Taurine plays an important role in a variety of physiological functions, pharmacological actions and pathological conditions. Many methods for taurine analysis, therefore, have been reported to monitor its levels in biological samples. This review discusses the following techniques: sample preparation; separation and determination methods including high-performance liquid chromatography, gas chromatography, ion chromatography, capillary electrophoresis and hyphenation procedures. It covers articles published between 1990 and 2001.

Chromatography↗

PubMed2002

Determination of trace level bromate and perchlorate in drinking water by ion chromatography with an evaporative preconcentration technique.

A simple sample preconcentration technique employing microwave-based evaporation for the determination of trace level bromate and perchlorate in drinking water with ion chromatography is presented. With a hydrophilic anion-exchange column and a sodium hydroxide eluent in linear gradient, bromate and perchlorate can be determined in one injection within 35 min. Prior to ion chromatographic analysis, the drinking water sample was treated with an OnGuard-Ag cartridge to remove the superfluous chloride and concentrated 20-fold using a PTFE beaker in a domestic microwave oven for 15 min. The recoveries of the anions ranged from 94.6% for NO2- to 105.2% for F-. The detection limits for bromate, perchlorate, iodate and chlorate were 0.1, 0.2, 0.1 and 0.2 microg/l, respectively. The developed method is applicable for the quantitation of bromate and perchlorate in drinking water samples.

Bromates↗

PubMed2002

Effects of common metal ions on the determination of anions by suppressed ion chromatography.

The effects of common metal ions (Na+, K+, Ca2+, Mg2+, Al3+ and Fe3+) on the determination of nitrate, phosphate and sulfate by suppressed ion chromatography were investigated. The responses of nitrate within 1-10 mg/l were not affected in the presence of six metal ions at 10 mg/l. The peak areas of 1.0 mg/l sulfate increased significantly at 10 mg/l Fe3+ or Al3+ up to 51.34 and 48.37%, respectively. In the presence of 10 mg/l Fe3+, the peak area of 1 mg/l and 10 mg/l phosphates decreased by 91.44 and 33.71%, respectively. At 10 mg/l Al3+ the peak areas of phosphate also increased slightly. The adverse effect of Fe3+ on the determination of phosphate could be overcome effectively by reducing the pH of the samples. The method to overcome the adverse effect was studied.

Anions↗

PubMed2002

Organic analysis by ion chromatography. 1. Determination of aromatic amines and aromatic diisocyanates by cation-exchange chromatography with amperometric detection.

A method has been developed for the simultaneous determination of a range of aromatic amines using cation-exchange chromatography performed on a standard ion chromatography column using d.c. amperometric detection. The analytes separated were 2,4- and 2,6-toluenediamine (2,4- and 2,6-TDA), aniline, o-toluidine, benzidine, p-chloroaniline, 4,4'-diaminodiphenyl (4,4'-DDP), m-nitroaniline and 1-naphthylamine. A Dionex CS12 column was used with gradient elution from an initial eluent of 5% CH3CN+35 mM H2SO4 to 27% CH3CN+35 mM H2SO4 (at 35 min). Detection limits in the range 2.6-22.6 microg/l were observed for all analytes except m-nitroaniline, for which the detection limit was 201 microg/l. Linear calibrations and good precision were observed and the method was applied to the determination of benzidine, p-chloroaniline and 1-naphthylamine in wastewater samples. Further, the separation was also used (after some modification of the eluent conditions) for the determination of 2,4- and 2,6-toluene diisocyanate (2,4- and 2,6-TDI) and 4,4'-methylenediphenyl diisocyanate (4,4'-MDI) after their hydrolysis to 2,4-TDA, 2,6-TDA and 4,4'-DDP. Detection limits for 2,6- and 2,4-TDI and 4,4'-MDI were 3.8, 8.2, and 11.2 microg/l, respectively. The method was applied to the determination of diisocyanates in air.

Amines↗