Quantitative analysis of trace elements in human blood and plasma by energy dispersive X-ray fluorescence

Feasibility of Lead Exposure Assessment in Blood Spots using Energy-Dispersive X-ray Fluorescence

Collecting blood spots from newborns is a common procedure used to diagnose multiple health conditions. Fingerstick blood samples are routinely collected from children to diagnose elevated blood lead levels. In our study, we wanted to test the feasibility of using a high-power energy-dispersive X-ray fluorescence (EDXRF) device to accurately measure the concentration of lead in blood spots. We created spotted standards of a known concentration of lead on a filter paper at different volumes and concentrations. We determined the detection limit for lead through repeated measurements of our standards and calibration line slopes. We also tested the variability of the measured lead concentration across procedures and spotted blood volumes and found no significant additions to uncertainty in measurements. Finally, we compared blood lead concentrations measured by EDXRF and atomic absorption spectroscopy (AAS) and found EDXRF to be a significant predictor of blood lead (n = 22, R = 0.98, p value <0.001) with an average detection limit of 1.7 μg/dL of blood lead. This detection limit is similar to that of the AAS technique, which is commonly used in clinical testing laboratories for blood lead surveillance. These findings provide a proof of concept that blood spots measured by EDXRF may be used as a surveillance tool for lead exposure, even at elevated blood lead levels of 2-3 μg/dL.

Environmental exposure of humans to bromide in the Dead Sea area: Measurement of genotoxicy and apoptosis biomarkers

Bromide (Br^-) is a bromine atom with a negative charge which is released mainly in the production of pesticides and flame retardants. It is also found naturally in seawater. Br¯ has been associated with many detrimental effects such as respiratory problems, gastric hemorrhages, and dermal burns. The aim of the study was to monitor serum bromide in humans and to correlate its level with genotoxicity and apoptosis in human. The study utilized comet assay, to measure DNA damage in peripheral leukocytes (i.e. T%DNA), enzyme-linked immunosorbent assay were used to determine fortilin level as an apoptosis marker, and spectrophotometry to measure serum Br¯ in two populations at the Dead Sea area, which are located close to and far from a local bromine factory: Ghor As-safi and Deir Alla, respectively. The biomarkers were compared with the correlating serum Br¯. A total of 397 individuals were involved in the study. The serum Br^- and the genotoxicity biomarker were significantly higher (p <  0.001) in Ghor As-safi than in Deir Alla. In contrast, serum fortilin did not differ significantly between the two regions (p >  0.05). T%DNA was significantly correlated (r = 0.867, p <  0.01) to serum Br¯. In conclusion, residing near a bromide source site is increasing the bromide body burden, and enhancing genotoxicity with no detectible apoptosis. Furthermore, the selected biomarkers could serve as tools to assess the toxicity of bromide as a consequence of environmental exposure.

The toxicology of bromide ion

Inorganic bromide is widely distributed in nature. Its natural physiological role in animal life is unknown. More than a century ago bromide was introduced in medicine as an antiepileptic drug. Nowadays, man is primarily exposed to bromide via food as the result of use of bromide-containing fumigants in intensive horticulture and in the treatment of food stocks. In this review exposure of man to bromide is described, and the pharmacological and toxicological effects of bromide ion are discussed.

Trace elements in human body fluids and tissues

Published figures for trace element concentrations in body fluids and tissues of apparently healthy subjects are widely divergent. For a considerable time, the apparent disparities were readily ascribed to biological sources of variation such as age, sex, dietary habits, physiological conditions, environmental exposure, geographical circumstances, or similar influences. Growing evidence, however, suggests that this interpretation may be seriously questioned in numerous instances. First, values obtained in reference materials leave no doubt that some previous studies must have been subject to gross analytical inaccuracies. Second, it has now been thoroughly documented that inadequate sample collection and manipulation may drastically distort the intrinsic trace element content of biological matrices. This review scrutinizes data reported by a number of investigators. In an effort to settle the currently flourishing confusion, critically selected reference values are set forth for trace element levels in human blood plasma or serum, packed blood cells, urine, lung, liver, kidney, and skeletal muscle tissue.

An ion chromatographic method for the simultaneous determination of inorganic phosphate, bromide, nitrate and sulphate in human serum

A direct method for the determination of inorganic phosphate, bromide, nitrate and sulphate in 100 microliter serum is described. After a 10-fold dilution, the sample is directly injected into an ion chromatograph without further pretreatment. The method described is highly accurate, and reproducible over longer periods. The serum concentrations of the four above-mentioned anions have been determined in 20 male and 20 female normal persons and found to be in agreement with the results of earlier studies.

Metal analysis by energy dispersive x-ray fluorescence of bovine brain tubulin and microtubule-associated proteins prepared by phosphocellulose chromatography

It has been shown by trace metal analysis that tubulin isolated from bovine brain does not contain strongly bound transition metal ions. The traces of zinc and iron found in the fraction of microtubule-associated proteins might originate from previously reported phosphatase activity (Larsson, H., Wallin, M. and Edström, A. (1979) J. Neurochem. 32, 155--161).

A new micromethod for colorimetric determination of zinc in serum

A simple micromethod with a colorimetric reagent of high sensitivity was developed for the determination of zinc in serum. For the color reagent 2-(2-pyridylazo)-5-dimethylaminophenol (PADAP) was used. Coefficients of variation of the within-day precision were 6.65 and 2.24% for zinc standard at concentrations of 0.1 and 0.5 microgram/ml, respectively. The mean recovery by this method was 101.2% (S.D.: 3.56%). Zinc concentrations measured by the above method showed good agreement with those by atomic absorption spectrophotometry, with a correlation coefficient of 0.934. Serum zinc values of 50 healthy adults (38 females, 12 males) ranged from 63 to 116 microgram/100 ml (mean: 89.68 microgram/100 ml, Sd.: 13.28 microgram/100 ml).