Microdetermination of mercury in biological samples. Part II. An apparatus for rapid automatic determination of mercury in digested samples

Abstract

Urine samples that have been cold-digested by potassium permanganatesulphuric acid mixture overnight are analysed in apparatus consisting of an automatic sample changer, pumps for transferring the sample solution to a purgation tower and adding tin(I1) chloride solution, which reduces mercury(I1) to metallic mercury, and a spectrophotometer. The mercury vapour is liberated from the solution in the tower by a flow of nitrogen and then taken through the absorption cell in the spectrophotometer where the light absorption at a wavelength of 253.7 nm is continuously recorded. After completion of the purgation, the mercury-free solution is transported back to the original tube in the sample changer by reversing the pumps, and the next analysis is started. The mercury content in the sample is calculated from standard graphs drawn from results with known amounts of mercury. Sixty digested samples, each containing 1 ml of urine, are analysed in about 2 hours without any manual work or supervision. In each sample about 1 ng of mercury can be detected, but normally the working range for urine samples is 0 to 400 ng ml-l of mercury(I1). The analysis can be applied to biological or any other samples that can be digested in a similar manner.IN a previous paper,l one of us described a rapid method for the determination of mercury in digested urine, which was based upon the reduction of mercury(I1) to the metallic state by tin(II), followed by removal of mercury vapour by purging with air and cold-vapour atomic-absorption determination of mercury. The speed of analysis was fairly high, and the detection limit about 2 ng of mercury in a 1-ml urine sample.At present, there is a great demand for trace determination of mercury in large series of samples of water, food, urine, blood and organs. To reduce the cost of such analyses it is essential to find methods which can bring down the amount of work needed to a minimum. Therefore, we have worked out an automatic method for the determination of mercury in samples that have been wet digested. This method depends upon the same basic principle as * For particulars of Part I of this series, see reference list, p. 229.

Comprehensive medical examination of a group of patients with alleged adverse effects from dental amalgams

“…The concentration of mercury was analyzed by atomic absorption (44,45). Renal function was assessed by measuring the glomerular filtration rate (creatinine clearance in ml/ min per 1.73 m2), the ability to concentrate urine within the collecting ducts of the nephrons (subcutaneous injection of 4 pg of desmopressin; Ferring, Malmo, Sweden), and by determining glomerular albuminuria by rocket immune electrophoresis of diurnal urine (detection limit > 5 mg/l).…”

Individual mercury exposure of chloralkali workers and its relation to blood and urinary mercury levels.

“…The solution was cooled and diluted to 50 ml with water. Two milliters of this solution were pipetted out and analyzed for mercury in the automatic flameless atomic absorption apparatus described by Lindstedt and Skare (10). Control experiments showed that the sensitivity of the method was not influenced by the presence of manganese ions and that no mercury was lost during the boiling.…”

Clinical study of patients with burning mouth

“…The thyroid test values were considered to be normal when they were in the range of the reference limits 10.0-26.0 pmol/1 (free T4 levels) and 0.30-5.00 mIU/1 (serum TSH). A urinary mercury analysis (U-Hg) was done by collecting and pooling urine for 24 h. The U-Hg concentration was analyzed at one occasion by atomic absorption (26,27), and concentrations exceeding the limit of 100 nmol Hg/1 urine were classified as abnormal (28).…”