@article {918,
	title = {Arsenic speciation in human urine: are we all the same?},
	journal = {Toxicology and Applied Pharmacology},
	volume = {198},
	number = {3},
	year = {2004},
	note = {ISI Document Delivery No.: 844GRTimes Cited: 26Cited Reference Count: 34},
	month = {Aug},
	pages = {297-306},
	type = {Review},
	abstract = {we studied the arsenic speciation in human urine samples by using high-performance liquid chromatography-inductively coupled plasma-mass spectrometry (HPLC-ICP-MS). We investigated the arsenic speciation in the urine collected from nine volunteers during a 3-day period after a meal of blue mussels, Mytilus edulis. We also studied the effect of cooking on the arsenic speciation. Arsenobetaine and dimethylarsinic acid (DMAA) were the major arsenic metabolites found in the urine samples. Significant amounts of unknown metabolites were also detected. The excretion patterns of arsenic from individuals were generally similar except for two subjects. One of whom excreted high amounts of arsenobetaine even though no arsenic-rich food was eaten for 3 days before the experiment. The results reveal that we need a better understanding of the metabolism of arsenic compounds by human. (C) 2004 Elsevier Inc. All rights reserved.},
	keywords = {arsenic, arsenobetaine, arsenosugar, ENVIRONMENT, HPLC, ICP-MS, IDENTIFICATION, INGESTION, LIQUID-CHROMATOGRAPHY, MASS-SPECTROMETRY, METABOLITES, METHYLATED ARSENICALS, mussel, PRODUCTS, TRIVALENT, urine},
	isbn = {0041-008X},
	url = {<Go to ISI>://000223146600007},
	author = {Lai, V. W. M. and Sun, Y. M. and Ting, E. and Cullen, W. R. and Reimer, K. J.}
}
@article {5168,
	title = {The arsenic eaters of Styria: a different picture of people who were chronically exposed to arsenic},
	journal = {Applied Organometallic Chemistry},
	volume = {15},
	number = {6},
	year = {2001},
	note = {ISI Document Delivery No.: 435TUTimes Cited: 7Cited Reference Count: 38},
	month = {Jun},
	pages = {457-462},
	type = {Review},
	abstract = {We have reviewed the case of residents of Styria, Austria, who are reported to have consumed large quantities of arsenic oxide (300-400 mg per dose) and remained in good health. Copyright (C) 2001 John Wiley \& Sons, Ltd.},
	keywords = {ACUTE PROMYELOCYTIC LEUKEMIA, arsenic, Austria, DRINKING-WATER, health effects, INGESTION, Styria},
	isbn = {0268-2605},
	url = {<Go to ISI>://000168897900003},
	author = {Przygoda, G. and Feldmann, J. and Cullen, W. R.}
}
@article {4862,
	title = {Determination of monomethylarsonous acid, a key arsenic methylation intermediate, in human urine},
	journal = {Environmental Health Perspectives},
	volume = {108},
	number = {11},
	year = {2000},
	note = {ISI Document Delivery No.: 373XPTimes Cited: 101Cited Reference Count: 48},
	month = {Nov},
	pages = {1015-1018},
	type = {Article},
	abstract = {In this study we report on the finding of monomethylarsonous acid [MMA(III)I in human urine. This newly identified arsenic species is a key intermediate in the metabolic pathway of arsenic biomethylation, which involves stepwise reduction of pentavalent to trivalent arsenic species followed by oxidative addition of a methyl group. Arsenic speciation was carried out using ion-pair chromatographic separation of arsenic compounds with hydride generation atomic fluorescence spectrometry detection. Speciation of the inorganic arsenite [As(III)], inorganic arsenate [As(V)], monomethylarsonic acid [MMA(V)], dimethylarsinic acid [DMA(V)], and MMA(III) in a urine sample was complete in 5 min. Urine samples collected from humans before and after a single oral administration of 300 mg sodium 2,3-dimercapto-1-propane sulfonate (DMPS) were analyzed for arsenic species. MMA(III) was found in 51 out of 123 urine samples collected from 41 people in inner Mongolia 0-6 hr after the administration of DMPS. MMA(III)in urine samples did not arise from the reduction of MMA(V) by DMPS. DMPS probably assisted the release of MMA(III) that was formed in the body. Along with the presence of MMA(III), there was an increase in the relative concentration of MMA(V) and a decrease in DMA(V) in the urine samples collected after the DMPS ingestion.},
	keywords = {3-dimercapto-1-propane sulfonate, ARSENIC SPECIATION, BIOMARKERS, CARCINOGENESIS, CHEMICAL FORMS, DIMETHYLARSINIC ACID, ENZYMATIC METHYLATION, EXCRETION, EXPOSURE, GLUTATHIONE-REDUCTASE, INGESTION, METABOLISM, METABOLITES, METHYLATION, MONOMETHYLARSONOUS ACID, sodium 2, SPECIATION, trivalent methylarsenic species, urine metabolites},
	isbn = {0091-6765},
	url = {<Go to ISI>://000165315600019},
	author = {Le, X. C. and Ma, M. S. and Lu, X. F. and Cullen, W. R. and Aposhian, H. V. and Zheng, B. S.}
}
@article {4861,
	title = {Speciation of key arsenic metabolic intermediates in human urine},
	journal = {Analytical Chemistry},
	volume = {72},
	number = {21},
	year = {2000},
	note = {ISI Document Delivery No.: 369XXTimes Cited: 187Cited Reference Count: 45},
	month = {Nov},
	pages = {5172-5177},
	type = {Article},
	abstract = {Biomethylation is the major human metabolic pathway for inorganic arsenic, and the speciation of arsenic metabolites is essential to a better understanding of arsenic metabolism and health effects. Here we describe a technique for the speciation of arsenic in human urine and demonstrate its application to the discovery of key arsenic metabolic intermediates, monomethylarsonous acid (MMA(III)) and dimethylarsinous acid (DMA(III)), in human urine. The study provides a direct evidence in support of the proposed arsenic methylation pathway in the human. The finding of MMA(III) and DMA(III) in human urine, along with recent studies showing the high toxicity of these arsenicals, suggests that the usual belief of arsenic detoxification by methylation needs to be reconsidered, The arsenic speciation technique is based on ion pair chromatographic separation of arsenic species on a 3-mum particle size column at 50 degreesC followed by hydride generation atomic fluorescence detection. Speciation of MMA(III), DMA(III), arsenite (As-III), arsenate (As-V), monomethylarsonic acid(MMA(V)), and dimethylarsinic acid (DMA(V)) in urine samples is complete in 6 min with detection limits of 0.5-2 mug/L. There is no need for any sample pretreatment. The capability of rapid analysis of trace levels of arsenic species, which resulted in the findings of the key metabolic intermediates, makes the technique useful for routine arsenic speciation analysis required for toxicological and epidemiological studies.},
	keywords = {ATOMIC FLUORESCENCE DETECTION, BLACKFOOT DISEASE, DRINKING-WATER, EXCRETION, EXPOSURE, INGESTION, METHYLATION, PERFORMANCE LIQUID-CHROMATOGRAPHY, SEPARATION, TEMPERATURE},
	isbn = {0003-2700},
	url = {<Go to ISI>://000165094000012},
	author = {Le, X. C. and Lu, X. F. and Ma, M. S. and Cullen, W. R. and Aposhian, H. V. and Zheng, B. S.}
}
@article {4673,
	title = {Metabolism of arsenic in primary cultures of human and rat hepatocytes},
	journal = {Chemical Research in Toxicology},
	volume = {12},
	number = {7},
	year = {1999},
	note = {ISI Document Delivery No.: 219JCTimes Cited: 81Cited Reference Count: 26},
	month = {Jul},
	pages = {560-565},
	type = {Article},
	abstract = {The liver is considered a major site for methylation of inorganic arsenic (iAs). However, there is Little data on the capacity of human liver to methylate iAs. This work examined the metabolism of arsenite (iAs(III)), arsenate (iAs(v)), methylarsine oxide ((MAsO)-O-III), methylarsonic acid (MAsv), dimethylarsinous acid (DMAsIII), and dimethylarsinic acid (DMAsV) in primary cultures of normal human hepatocytes. Primary rat hepatocytes were used as methylating controls, iAs(III) and (MAsO)-O-III were metabolized more extensively than iAs(v) and MAsv by either cell type. Neither human nor rat hepatocytes metabolized DMAsIII or DMAsV. Methylation of iAs(III) by human hepatocytes yielded methylarsenic (MAs) and dimethylarsenic (DMAs) species; (MAsO)-O-III was converted to DMAs. The total methylation yield (MAs and DMAs) increased over the range of 0.1 to 4 mu M iAs(III). However, DMAs production was inhibited by iAs(III) in a concentration-dependent manner, and the DMAs/MAs ratio decreased. iAs(III) (10 and 20 mu M) inhibited both methylation reactions. Inhibition of DMAs synthesis resulted in accumulation of iAs and MAs in human hepatocytes, suggesting that dimethylation is required for iAs clearance from cells. Methylation capacities of human hepatocytes obtained from four donors ranged from 3.1 to 35.7 pmol of iAs(III) per 10(6) cells per hour and were substantially lower than the methylation capacity of rat hepatocytes (387 pmol of iAs(III) per 10(6) cells per hour). The maximal methylation rates for either rat or human hepatocytes were attained between 0.4 and 4 mu M iAs(III). In summary, (i) human hepatocytes methylate iAs, (ii) the capacities for iAs methylation vary among individuals and are saturable, and (iii) moderate concentrations of iAs inhibit DMAs synthesis, resulting in an accumulation of iAs and MAs in cells.},
	keywords = {ASSAY, ENZYMATIC METHYLATION, IN-VITRO, INGESTION, LIVER, PURIFICATION, TOXICITY, URINARY-EXCRETION},
	isbn = {0893-228X},
	url = {<Go to ISI>://000081603300003},
	author = {Styblo, M. and Del Razo, L. M. and LeCluyse, E. L. and Hamilton, G. A. and Wang, C. Q. and Cullen, W. R. and Thomas, D. J.}
}
@article {2852,
	title = {DETERMINATION OF URINARY ARSENIC AND IMPACT OF DIETARY ARSENIC INTAKE},
	journal = {Talanta},
	volume = {40},
	number = {2},
	year = {1993},
	note = {ISI Document Delivery No.: KU309Times Cited: 47Cited Reference Count: 40},
	month = {Feb},
	pages = {185-193},
	type = {Article},
	abstract = {An analytical method based on microwave decomposition and flow injection analysis (FIA) coupled to hydride generation atomic absorption spectrometry (HGAAS) is described. This is used to differentiate arsenite [As(III)], arsenate [As(V)], monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA) from organoarsenic compounds usually present in seafood. Without microwave digestion, direct analysis of urine by HGAAS gives the total concentration of As(III), As(V), MMA and DMA because organoarsenic compounds such as arsenobetaine, usually found in most seafood, are not reducible upon treatment with borohydride and therefore cannot be determined by using the hydride generation technique. The microwave oven digestion procedure with potassium persulfate and sodium hydroxide as decomposition reagents completely decomposes all arsenicals to arsenate and this can be measured by HGAAS. Microwave decomposition parameters were studied to achieve efficient decomposition and quantitative recovery of arsenobetaine spiked into urine samples. The method is applied to the determination of urinary arsenic and is useful for the assessment of occupational exposure to arsenic without intereference from excess organoarsenicals due to the consumption of seafood. Analysis of urine samples collected from an individual who ingested some seafood revealed that organoarsenicals were rapidly excreted in urine. After the ingestion of a 500-g crab, a 10-fold increase of total urinary arsenic was observed, due to the excretion of organoarsenicals. The maximum arsenic concentration was found in the urine samples collected approximately between 4 to 17 hr after eating seafood. However, the ingestion of organoarsenic-containing seafoods such as crab, shrimp and salmon showed no effect on the urinary excretion of inorganic arsenic, MMA and DMA.},
	keywords = {arsenobetaine, ATOMIC-ABSORPTION SPECTROMETRY, EMISSION-SPECTROMETRY, EXCRETION, HYDRIDE GENERATION, INGESTION, LIQUID-CHROMATOGRAPHY, METABOLISM, REDUCTION, SPECIATION},
	isbn = {0039-9140},
	url = {<Go to ISI>://A1993KU30900013},
	author = {Le, X. C. and Cullen, W. R. and Reimer, K. J.}
}
