Atomic Absorption Spectrophotometric Microdetermination of Total Mercury in Undigested Biological Samples

Abstract

The influence of reaction time upon stannous (II) chloride as a reductant in the cold-vapor atomic absorption spectrophotometric method was investigated. In this comparative study, virtually all operating conditions, including volumes and chemicals used, were made identical except for the redesigning of the reaction vessels. The use of a reaction mixing time of 2 minutes (TR method), rather than immediate bubbling with aspiration (IL method) of total mercury from undigested biological samples, has several advantages. There is an average 4.5-fold increase in sensitivity of peak height readings with virtually no loss of mercury vapor from the reaction vessel by diffusion. Using the TR method also eliminated interaction of mercury with the matrices investigated, viz., undigested blood, undigested saliva, undigested urine, and digested hair samples. The average recovery for the TR method was superior to the IL method, 99.3 +/- 3.2% vs. 84.7 +/- 3.3%, p less than 0.05. In addition, mercury concentrations determined with the TR method were identical using either peak area or peak height readings. It was also found that concentrations determined using either the formulae given by Magos and Clarkson (4) and Farant et al. (5) or an aqueous calibration curve were equivalent. Only 0.2-1.0 mL of biological samples was needed for each analysis in the study.

Concentrations of heavy metals in maternal and umbilical cord blood

“…Quality control for mercury was carried out in collaboration with Centre de Toxicologie du Qubec, Canada. Detailed methods for both inorganic and organic mercury have been described previously (Ngim et al 1989).…”

Epidemiologic Study on the Association between Body Burden Mercury Level and Idiopathic Parkinson's Disease

“…Samples of blood, urine and scalp hair, collected from the subjects were analyzed without knowledge of their diagnoses for total mercury using the PerkinElmer model 107 atomic absorption spectrophotome ter and stannous (II) chloride as the reductant by cold-vapor technique [31]. The laboratory partici pated in an interlaboratory comparison program for mercury analysis with the Quebec Centre of Toxicol ogy at the University of Laval, Que., Canada, since 1984.…”