Multielement electrothermal atomic absorption spectrometry: a study on direct and simultaneous determination of chromium and manganese in urine

Chromium in Postmortem Material

Recently, considerable attention has been paid to the negative effects caused by the presence and constant increase in concentration of heavy metals in the environment, as well as to the determination of their content in human biological samples. In this paper, the concentration of chromium in samples of blood and internal organs collected at autopsy from 21 female and 39 male non-occupationally exposed subjects is presented. Elemental analysis was carried out by an electrothermal atomic absorption spectrometer after microwave-assisted acid digestion. Reference ranges of chromium in the blood, brain, stomach, liver, kidneys, lungs, and heart (wet weight) in the population of Southern Poland were found to be 0.11-16.4 ng/mL, 4.7-136 ng/g, 6.1-76.4 ng/g, 11-506 ng/g, 2.9-298 ng/g, 13-798 ng/g, and 3.6-320 ng/g, respectively.

Simultaneous determination of arsenic, cadmium, copper, chromium, nickel, lead and thallium in total digested sediment samples and available fractions by electrothermal atomization atomic absorption spectroscopy (ET AAS)

This study describes the optimization and validation of a quick and simple method for the simultaneous determination of total content and available fractions of As, Cr, Cu, Ni, Pb and Tl in sediments by ET AAS, which has been proved to be useful for environmental research. The optimization was carried out using a 3(3) Box-Behnken factorial design which was applied to matrices of total digestion and to stages 1 and 2 of the modified BCR sequential extraction scheme for sediments in order to determine the appropriate atomization temperatures and masses for the chemical modifiers: Pd(NO(3))(2) and Mg(NO(3))(2). The simultaneous determination of the elements in all matrices considered was performed, without the use of chemical modifiers at atomization temperatures of 1700 °C for Cd and Tl, and 2100 °C for As, Cu, Cr, Ni and Pb, using a standard calibration curve for calibration purposes. The characteristic masses and limits of detection obtained were 36.5, 1.8, 6.5, 28, 34, 46.5 and 48 ρg and 0.11, 0.001, 0.022, 0.04, 0.2, 0.03 and 0.003 μg g(-1) for As, Cd, Cr, Cu, Ni, Pb and Tl, respectively. The analytical procedure was validated by analyzing three sediment certified reference materials (CRM NCS DC 73315 and LKSD-4 for total content and BCR 701 for available fractions). Good accuracy was obtained (tested statistically, P=0.05, and shown by the high recovery for each element in each matrix), except for total As in the matrix of total digestion, where losses of the analyte could be attributed to sample treatment with HNO(3). The precision of the procedure was between 0.6% and 6%.

Urinary copper excretion before and after oral intake of d-penicillamine in parents of patients with Wilson's disease

BACKGROUND

Urinary copper excretion higher than 100 μg/24 h is useful for diagnosing Wilson's disease. d-Penicillamine challenge test may produce higher levels than 1400 μg/24 h, allowing for better diagnostic accuracy. This study investigated whether heterozygotes reach this value and compared copper serum levels, ceruloplasmin, and urinary copper excretion before and after administering d-penicillamine to the parents of Wilson's disease patients.

METHODS

Fifty parents of adult patients were enrolled to obtain copper serum levels and ceruloplasmin along with 24-h urinary copper excretion before and after administering 1g d-penicillamine.

RESULTS

Serum ceruloplasmin and copper levels were significantly lower in fathers than in mothers (mean 21.8×27.8 mg%; 71.4×88.0 μg%; p ≤ 0.001). The mean of basal 24-h urinary copper excretion was higher in fathers (26.2×18.7 μg/24 h, p=0.01), but did not differ between the genders after d-penicillamine (521.7×525.3, range 31.6-1085.1 μg/24h, p=0.8).

CONCLUSIONS

The mean values of serum copper, ceruloplasmin, and basal urinary copper excretion were different between males and females. The current diagnostic threshold of 24-h urinary copper excretion after d-penicillamine was not reached by heterozygotes. The increased urinary copper excretion after d-penicillamine challenge was much higher than fivefold the upper limit of normal urinary copper excretion in the majority of heterozygotes and should not be taken into account when diagnosing Wilson's disease.