Acetic Acid ; analysis ; Chromatography, Ion Exchange ; Workplace

Chromatography, Ion Exchange ; Hemoglobins, Abnormal ; analysis ; Humans ; Male

Chromatography, Ion Exchange ; Hemoglobins, Abnormal ; analysis ; Humans ; Male

Air ; analysis ; Anions ; analysis ; Chromatography, Ion Exchange ; Ions ; analysis ; Workplace

PURPOSE: To elucidate the anti-oxidant effect of extract fractions from Xanthium strumarium L. on lens protein by crosslinking assay. METHODS: [(1 4)C] N-formyl-lysine was synthesized and purified by ion exchange chromatography. The crosslinking activities of extract fractions(Xan Crude, Xan CHCl3, Xan EtAc and Xan H2O) to lens protein were determined by incorporation with [(14)C] N-formyl-lysine. RESULTS: It was observed that Xan Crude, Xan CHCl3, and Xan EtAc extracted from Xanthium strumarium L. showed approximately 10% of antioxidant effect whereas Xan H2O showed no effect by crosslinking assay. CONCLUSIONS: This study showed that the crosslinking assay described in this study can be developed as a potential tool to screen the anti-oxidant effect rapidly and accurately compared to MTT assay. The result was compared to MTT assay using Human Lens epithelial cell line.
Antioxidants ; Cataract ; Chromatography, Ion Exchange ; Epithelial Cells ; Humans ; Xanthium*

OBJECTIVETo develop a method for determination of mandelic acid (MA) and phenylglyoxylic acid (PGA) in urine by reagent-free ion chromatography.

METHODSIon chromatography was performed on an AS19 column with a gradient elution solution containing 10-35 mmoL/L KOH at a flow rate of 1.00 ml/min, and MA and PGA were detected at ultraviolet wavelengths of 225 nm and 254 nm, respectively. The samples were diluted 10 times with purified water, then purified on a silver column to remove high concentrations of chloride ion, and injected after being filtered through a 0.2-µm m filter membrane.

RESULTSThe recoveries of standard addition of MA and PGA were 96.5% and 99.3%, respectively, with both relative standard deviations less than 5.0%. Good linear relationships were noted in the range of 1.0-100.0 mg/L for both MA and PGA (r >0.9995). The detection limits of MA and PGA were 0.02 mg/L and 0.05 mg/L, respectively; the minimum detectable concentrations of MA and PGA were 0.2 mg/L and 0.5 mg/L (when the sampling amount was 5.0 ml and diluted to 50.0 ml with water, and the injection volume was 300 µL).

CONCLUSIONSThis method is fast, convenient, and highly sensitive and selective. It can be used for the analysis of MA and PGA in the urine of styrene-exposed workers.

Chromatography, Ion Exchange ; Glyoxylates ; urine ; Humans ; Mandelic Acids ; urine ; Styrene

A bromoperoxidase from Gracilaria lemaneiformis was purified to homogeneity using a multi-step process of ammonium sulfate precipitation (AS), dialysis, and DEAE-cellulose 52 anion exchange chromatography. The bromoperoxidase activity was unstable or undetectable in crude extract solution. However, it became stable with electrophoretic purity after this multiple purification process. The anion exchange chromatography purification was a critical step in the purification process, which effectively eliminated the phycobiliprotein and smucilaginous polysaccharides. The purified bromoperoxidase was a monomeric enzyme with the relative molecular masses of 66 kD as determined by denaturing and native gradient gel electrophoresis. The optimal pH for bromoination was 6.0 and bromoperoxidase activity was stable as stored at a broad pH range of 3.0-9.0. Of a range of compounds tested, only vanadium enhanced bromoperoxidase activity. Kinetic studies for the bromination of monochlorodimedone (MCD) showed that the Km values of Br- and H2O2 are 53.5 micromol/L, 38 micromol/L respectively.
Chromatography, Ion Exchange ; methods ; Enzyme Stability ; Gracilaria ; enzymology ; Hydrogen-Ion Concentration ; Kinetics ; Peroxidases ; isolation & purification ; metabolism

Air Pollutants, Occupational ; analysis ; Ammonium Sulfate ; analysis ; Chromatography, Ion Exchange ; methods ; Workplace

OBJECTIVETo evaluate the method for collecting NO2 in workplace air using a solid adsorbent and determining the concentration of NO2 by ion-exchange chromatography.

METHODSNO2 in workplace air was collected using sampling tubes filled with 13X molecular sieve soaked with triethanolamine, and the samples were desorbed with a certain concentration of triethanolamine solution to obtain NO2(-). NO2(-) was separated with an anion exchange chromatography column and quantified by a conductivity detector. The concentration of NO2 was determined based on the conversion coefficient of NO2 and NO2(-).

RESULTSDifferent concentrations of NO2 (standard gas) was collected using the sampling tubes at different time points, and the sampling efficiency and desorption efficiency could reach more than 90%. The penetrating capacity of sampling tubes was more than 1.1 mg. The comparative test shows that there was no significant difference between the new method and national standard method (solution absorption) (P > 0.05). The samples could be stored at room temperature for more than 16 days. The calibration curve plotted in the new method was linear in the range of 0.1∼20.0 µg/ml, with a correlation coefficient of 0.9998; the detection limit was 0.01 µg/ml; the minimum detectable concentration was 0.05 mg/m(3) (V0 = 3.0 L).

CONCLUSIONThis determination method meets the requirements of Guide for establishing occupational heath standards-Part 4 Determination methods of air chemicals in workplace (GBZ/T 210.4-2008) and shows obvious advantages for determination of NO2 in workplace air.

Air ; analysis ; Air Pollutants, Occupational ; analysis ; Chromatography, Ion Exchange ; methods ; Nitrogen Dioxide ; analysis ; Workplace

OBJECTIVETo investigate the seasonal characteristics and the sources of elements and ions with different sizes in the aerosols in Beijing.

METHODSSamples of particulate matters (PM2.5), PM10, and total suspended particle (TSP) aerosols were collected simultaneously in Beijing from July 2001 to April 2003. The aerosol was chemically characterized by measuring 23 elements and 18 water-soluble ions by inductively coupled plasma-atomic emission spectroscopy (ICP-AES) and ion chromatography (IC), respectively.

RESULTSThe samples were divided into four categories: spring non-dust, spring dust, summer dust, and winter dust. TSP, PM10, and PM2.5 were most abundant in the spring dust, and the least in summer dust. The average mass ratios of PM > 10, PM2.5-10, and PM2.5 to TSP confirmed that in the spring dust both the large coarse (PM > 10) and fine particles (PM2.5) contributed significantly in summer PM2.5, PM2.5-10, and PM > 10 contributed similar fractions to TSP, and in winter much PM2.5. The seasonal variation characteristics of the elements and ions were used to divide them into four groups: crustal, pollutant, mixed, and secondary. The highest levels of crustal elements, such as Al, Fe, and Ca, were found in the dust season, the highest levels of pollutant elements and ions, such as As, F-, and Cl-, were observed in winter, and the highest levels of secondary ions (SO4(2-), NO3-, and NH4+) were seen both in summer and in winter. The mixed group (Eu, Ni, and Cu) showed the characteristics of both crustal and pollutant elements. The mineral aerosol from outside Beijing contributed more than that from the local part in all the reasons but summer, estimated using a newly developed element tracer technique.

Aerosols ; China ; Chromatography, Ion Exchange ; Environmental Monitoring ; Particle Size ; Particulate Matter ; analysis ; chemistry ; Seasons ; Spectrophotometry, Atomic