Foà V, Colombi A, Maroni M, Buratti M, Calzaferri G
Sci Total Environ. 1984 Mar 15;34(3):241-59. doi: 10.1016/0048-9697(84)90066-4.
Total As content may be determined in blood and urine by means of an AAS method that involves reduction of As to its volatile hydride and ashing at 600 degrees C with MgO and Mg (NO3)2. Separation of inorganic As (InAs), monomethylarsonic acid (MMA) and dimethylarsinic acid (DMAA) by ion-exchange chromatography, followed by direct AAS analysis, allows the determination of each As species in the urine. In a reference population of 148 subjects with only normal environmental exposure to As, total As concentration in the urine averages 17.2 +/- 11.1 micrograms/l. Urinary As consists of 10% each of InAs, MMAA and DMAA, the remaining 70% consisting of other forms of organic As. Blood As concentration averages 5.1 +/- 6.9 micrograms/l and correlates significantly with the urinary concentration of InAs and the sum of its metabolites (InAs + MMAA + DMAA). Inorganic arsenic undergoes methylation in the organism. After ingestion of high quantities of As2O3, the time course of excretion of its metabolites indicates that As methylation occurs by a saturable mechanism. In workers exposed to As2O3, InAs, MMAA and DMAA are the only chemical forms of As excreted in the urine that are relevant to a study of occupational exposure. Blood As concentration is proportional to exposure and correlates only with urinary DMAA excretion; DMAA seems to be the most appropriate single indicator of exposure. At high levels of exposure (total As excretion above 200 micrograms/l), As accumulates in the organism and DMAA excretion reflects its accumulation. At low levels of exposure (total As excretion below 50 micrograms/l) a short-term accumulation does not occur and the best biological indicator of exposure is InAs excretion. Seafood ingestion brings about a marked increase in urinary excretion of total As that lasts for 24-48 h and is not accompanied by any increase in InAs, MMAA or DMAA excretion. Organic As from seafood does not mix with the pool of inorganic As in the organism and may be separately detected in urine. In the biological monitoring of human exposure to As, particularly in the case of high urinary values, the speciation of the chemical forms of As in urine is necessary in order to establish with certainty the source, industrial or alimentary, of exposure.
总砷含量可通过原子吸收光谱法（AAS）在血液和尿液中进行测定，该方法包括将砷还原为其挥发性氢化物，并在600℃下与氧化镁和硝酸镁一起灰化。通过离子交换色谱法分离无机砷（InAs）、一甲基胂酸（MMA）和二甲基胂酸（DMAA），然后直接进行原子吸收光谱分析，可测定尿液中每种砷形态。在148名仅正常环境接触砷的受试者参考人群中，尿液中总砷浓度平均为17.2±11.1微克/升。尿砷中InAs、MMAA和DMAA各占10%，其余70%为其他有机砷形式。血液砷浓度平均为5.1±6.9微克/升，与尿液中InAs浓度及其代谢产物总和（InAs + MMAA + DMAA）显著相关。无机砷在生物体内会发生甲基化。摄入大量三氧化二砷后，其代谢产物的排泄时间进程表明砷甲基化通过饱和机制发生。在接触三氧化二砷的工人中，InAs、MMAA和DMAA是尿液中排出的与职业接触研究相关的唯一砷化学形态。血液砷浓度与接触程度成正比，且仅与尿液中DMAA排泄相关；DMAA似乎是最合适的单一接触指标。在高接触水平（总砷排泄量高于200微克/升）时，砷在生物体内蓄积，DMAA排泄反映其蓄积情况。在低接触水平（总砷排泄量低于50微克/升）时，不会发生短期蓄积，最佳的接触生物指标是InAs排泄。摄入海鲜会使尿中总砷排泄量显著增加，持续24 - 48小时，且InAs、MMAA或DMAA排泄量无任何增加。海鲜中的有机砷不会与生物体内的无机砷混合，可在尿液中单独检测到。在人体接触砷的生物监测中，特别是在尿值较高的情况下，为了确定接触的来源（工业或饮食），有必要对尿液中砷的化学形态进行形态分析。
