Mercury contamination of heavy metal collection containers

We investigated discordant urinary mercury testing results from 2 patients with potential mercury exposures. Two patients had mercury levels of 634 an d >1,000 mu g/L respectively Although repeat 24 h urine mercury levels were elevated, spot urines were negative. Investigation revealed that technical HCl with high mercury content had been added to the 24 h urine collection containers. Subsequently, 20 hospitals were contacted to determine their he avy metals testing procedure and to analyze the acid used for mercury, Most hospitals contacted used acid in the preparation of their urine heavy meta l collection containers. Of 13 HCl samples tested, 5 had low levels of merc ury and I had heavy mercury content. Acid added to heavy metal collection c ontainers should be of high purity grade to avoid mercury contamination of samples.