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Mercury is a heavy metal with high toxicity, the level of which depends on the form of the metal. One of the newer techniques for determining trace amounts of total mercury in various materials, including biological samples, is thermal decomposition, amalgamation and atomic absorption spectrometry (TDA AAS). The TDA AAS method was optimized and validated using a mercury analyzer (DMA-80). The limits of detection for mercury were 0.10 and 0.20 μg/L (nickel and quartz boats, respectively). The working range of the calibration curve was at least from 0.6 to 200 ng Hg/mL; the intra-day precision in samples (RSD)-in the range of: 1.66-6.86% (blood), 0.82-1.47% (urine) and 2.01-3.44% (hair); the inter-day precision (over 8 days): 2.51%, and 2.5% (blood spiked with 2.5 and 10 ng Hg, respectively), 5.10% and 3.16% (urine spiked with 2.0 and 6.0 ng Hg, respectively). The accuracy (as relative error, mean value) determined on the basis of the study of reference materials of blood (Seronorm Trace Elements Whole Blood L-1, L-2, L-3), urine (Seronorm Trace Elements Urine, Urine L-2), and hair (Human Hair NIES CRM No. 13) was: 2.00% (blood), 0.50% (urine) and 0.86% (hair); recovery of 2.5 ng Hg (blood): 93-97%. The method was used for the determination of mercury in 76 samples of various biological matrices, including samples of whole blood, urine, hair, bile and vitreous humor. Mercury concentrations in postmortem blood (n = 24) were in the range: 0.61-12.4 μg/L (median 3.02 μg/L); urine (n = 12): 0.16-2.19 μg/L (median 0.81 μg/L); hair (n = 14): 0.08-0.53 μg/g (median 0.22 μg/g); bile (n = 12): 1.15-7.11 μg/L (median 2.41 μg/L and vitreous humor (n = 13): 0.22-1.01 μg/L (median 0.47 μg/L). The method is suitable for the purposes of forensic toxicology analysis., (© The Author(s) 2019. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Changes in urinary porphyrin excretion patterns (porphyrin profiles) during prolonged mercury exposure are attributable to mercury accumulation in the kidney and to consequent effects of Hg2+ on renal porphyrin metabolism. In the present study, we evaluated the quantitative relationship of urinary porphyrin concentrations to mobilizable renal mercury content, using the metal chelator 2,3-dimercapto-1-propanesulfonic acid (DMPS) to modulate kidney mercury levels. Rats exposed to methylmercury hydroxide (MMH) at 10 ppm in drinking water for 6 weeks were treated with up to 3 consecutive doses of DMPS (100mg/kg, ip) at 72-h intervals. Consistent with previous findings, the concentrations of pentacarboxyl- (5-) and copro- (4-) porphyrins and of an atypical porphyrin specific to mercury exposure, precoproporphyrin, were significantly elevated in urine of MMH-exposed rats, compared with that of rats exposed to distilled water (dH2O) for the same period. Consecutive DMPS treatments of MMH-exposed rats significantly decreased kidney concentrations of total, as well as Hg2+ and CH3Hg+ species, and promoted increased urinary mercury excretion. Concomitantly, DMPS treatment decreased both kidney and urinary porphyrin concentrations, consistent with depletion of renal mercury levels. Regression analyses demonstrated a high correlation (r approximately 0.9) between prechelation urinary porphyrins and postchelation urinary mercury levels and also between prechelation urinary porphyrins and prechelation kidney mercury concentrations. These findings demonstrate that urinary porphyrin concentrations relate quantitatively to DMPS-mobilizable mercury in the kidney and, therefore, serve as a biochemical measure of renal mercury content.

I describe a sensitive, specific, automated method for determination of mercury in urine by the "flameless atomic absorption" technique. One can analyze 20 samples per hour, with less than 0.5-ml samples of urine. The detection limit is 0.01 mumol/liter (2mug/liter) and the mean coefficient of variation 12%. The procedure is being used to monitor mercury excretion by workers exposed to mercury.

In this procedure a single-beam spectrophotometer is used without background correction. By the method of Magos [Analyst (London) 96, 847 (1971)] mercury in undigested urine is complexed to L-cysteine in acid solution. At high pH and in the presence of stannous ions, mercury ions are reduced to elemental mercury. The mercury vapor is partitioned above the reagent solution in a specially designed chemical reduction apparatus similar in principle to that used by Kubasik et al. [Clin. Chem. 18, 1326 (1972)]. The vapor is then flushed by air through an "absorption" cell, where the absorption of the mercury line at 253.7 nm is measured. The value obtained for inorganic mercury subtracted from that for total mercury gives a value for organic mercury. CV's for the inorganic mercury procedure at 40 and 5 mug/liter concentrations were 3.1% and 7.5%, respectively. The detection limit is 0.82 mug/liter. The CV for the total-mercury procedure (20 mug/liter) was 2.6%. Mean analytical recoveries of organic and inorganic mercury were 96.5% and 101%, respectively. We investigated storage conditions for urine and compared results by the present technique with those by activation analysis. Our method is a convenient way to screen individuals who have been exposed to a mercury hazard.

Mercuric chloride was accidentally ingested by a nineteen-month old boy. He exhibited severe symptoms of inorganic mercury poisoning including acute renal failure. The blood mercury level at the time of admission to hospital was 1920 ng/mL. Following emergency hemodialysis, BAL (2, 3-dimercaptopropanol) therapy and penicillamine treatment, blood levels fell to 500 ng Hg/mL and urine production restarted six days after exposure. Urine mercury reached a high of 2349 ng/mL but rapidly decreased to less than 100 ng/mL within eight days after resumption of voiding. The patient was discharged from hospital a month after admission and follow-up examinations have indicated no permanent renal damage. Blood, hair, and urine samples collected 19 months after the exposure showed normal mercury levels (blood, 6 ng Hg/mL; urine, 7 ng Hg/mL; and hair 500-900 ng Hg/g).