Martina Turfeld

Determination of physiological palladium, platinum, iridium and gold levels in human blood using double focusing magnetic-sector field inductively coupled plasma mass spectrometry

A procedure is described for the determination of Pd, Ir, Pt and Au in human blood at environmental concentrations based on double focusing magnetic sector field ICP-MS. It is shown that the practical detection limits in such complex matrices are not essentially limited by instrumental capabilities, but are mainly a result of blank values and spectral interferences. Feasible ways are shown to reduce these blanks and interferences. Ultraviolet photolysis was found to be advantageous over mineral acid digestion techniques, because minimal reagent addition is required. Additional sub-boiling distillation of the commercially available ultrapure nitric acid, working in a clean-air laboratory and a skillful cleaning of all materials resulted in a further reduction of blanks. With the exception of Au, detection limits in blood samples were found to be well below 1 ng l -1 . Taking into account a dilution factor of 22.4 the detection limits related to the final solution were between 0.01 and 0.02 ng l -1 . The Pd, Ir, Pt and Au were detectable in the blood samples of all seven unexposed volunteers.

New horizons in human biomonitoring of environmentally and occupationally relevant metals—sector-field ICP-MS versus electrothermal AAS

Sector-field ICP-MS (SF-ICP-MS) was used for the quasi-simultaneous determination of selected trace and ultra-trace elements of occupational and environmental interest, such as Al, Co, Cr, Cu, Fe, Mn, Ni, Pt, V and Zn, in human urine and serum. In the case of urine, Pb, Cd and Tl were additionally determined. Sample pretreatment was restricted to UV photolysis and to a subsequent moderate dilution with 0.5% HNO3 solution without using any chemical separation and enrichment. Contamination was carefully controlled at each step of the analytical procedure. Calibration was carried out by the standard addition procedure. Owing to spectral interferences, the determination of Al, Co, Cr, Cu, Fe, Ni, V and Zn was performed in the medium resolution (MR) mode (m/Δm ≅ 3000), while the determination of non-interfered elements, such as Cd, Mn, Pb, Pt and Tl, was carried out at low resolution (LR) to gain a maximum of sensitivity. The accuracy of the procedure was checked by the analysis of commercially available quality control serum and urine samples, by comparison with electrothermal (ET-)AAS as a second independent method and by successful participation in an inter-laboratory comparison programme. The results obtained with both methods were in excellent agreement. Regarding the quality control materials, good agreement was also achieved between the found and assigned values. The described SF-ICP-MS multi-element method is thus suitable for the quasi-simultaneous determination of trace and ultra-trace elements in urine and serum covering a wide range of concentrations. It is especially valuable for rapid multi-element screening purposes in cases of unknown exposures (non-target screening) and for determinations at very low concentrations, which are not accessible to AAS techniques.

Determination of physiological platinum levels in human urine using magnetic sector field inductively coupled plasma mass spectrometry in combination with ultraviolet photolysis

An extremely sensitive and reliable procedure for the determination of physiological (normal) Pt levels in human urine is described based on UV photolysis of the sample followed by the determination of Pt with magnetic sector field ICP-MS. Owing to the low blank values, which are a consequence of the minimal reagent addition required, UV photolysis was used to decompose the organic matrix components. Magnetic sector field ICP-MS operated in the low resolution mode afforded detection limits that were 100 times lower than those obtained in the high resolution mode or with conventional quadrupole ICP-MS and was found to be advantageous for the ultratrace determination of non-interfered isotopes. The detection limit in urine samples was 0.24 ng l–1 using standard nickel cones. The use of a high performance nickel skimmer cone did not result in an improvement in the detection limit, because the analyte and background signals were enhanced to a similar extent. The urinary Pt levels in 16 non-exposed persons ranged between 0.48 and 7.65 ng l–1(arithmetic mean: 1.72 ng l–1).

Exposure to lead and cadmium of children living in different areas of North-West Germany: results of biological monitoring studies 1982–1986

SummaryBetween 1982 and 1986 several surveys were carried out to determine the levels of lead and cadmium in blood, urine, and shed deciduous teeth (incisors only) of children living in rural, suburban, urban, and industrial areas of North-West Germany. Blood lead (PbB) and blood cadmium (CdB) were measured in about 4000 children. In rural, suburban and urban areas the median PbB levels vary between 5.5 and 7 μg/dl, with 98th percentiles varying between 10 and 13 μg/dl. The median CdB levels are between 0.1 and 0.2 μg/dl, with 95th percentiles between 0.3 and 0.4 μg/l. Children from urban areas have significantly higher PbB levels than children from rural and suburban areas. Regarding CdB no differences could be detected. Children living in areas around lead and zinc smelters, particularly those living very close to the smelters, have substantially increased PbB and CdB levels. Children from lead worker families also have substantially increased PbB and CdB levels. The lead levels in shed milk teeth (PbT) were determined in about 3000 children. In rural, suburban and urban areas the median PbT levels are between 2 and 3 μg/g, with 95th percentiles between 4 and 7 μg/g. Children from urban areas have significantly higher PbT levels than children from rural and suburban areas. The highest PbT levels (on a group basis) are in children from nonferrous smelter areas. The median levels of lead in urine (PbU) are between 6 and 10 μg/g creatinine, with 95th percentiles between 20 and 30 μg/g creatinine. Children from polluted areas have higher PbU levels than children from less polluted areas. The median levels of cadmium in urine (CdU) are in the order of 0.1 μg/g creatinine, with 95th percentiles being in the range of 0.5 and 1.0 μg/g creatinine. Girls have higher CdU levels than boys. There are no differences between groups of children from different areas. Children from lead worker families have higher PbU and CdU levels than otherwise comparable children. The results of the present studies indicate a further decrease of PbB in children from North-West Germany since the CEC blood lead campaigns carried out in 1979 and 1981. The decrease of lead exposure also seems to be reflected by a decrease of tooth lead levels.

Internal lead and cadmium exposure in 6-year-old children from western and eastern Germany

Lead and cadmium levels in blood and deciduous teeth (shed incisors only) of 6-year-old German children were determined in 1991 in a large epidemiological study carried out in rural and urban areas of western Germany (Duisburg, Essen, Gelsenkirchen, Dortmund, Borken) and eastern Germany (Leipzig, Halle, Magdeburg, Osterburg, Gardelegen, Salzwedel). In total, blood lead and cadmium levels of 2311 German children and tooth lead and cadmium levels of 790 German children were analyzed. Blood lead levels were generally low in all study areas with geometric means between 39.3 μg/1 and 50.8 μg/l in the western German and between 42.3 μg/1 and 68.1 μg/l in the eastern German study areas. The mean blood lead level of Turkish children (n = 213) living in the western German study areas was 50.1 μg/l and thus 5.6 μg/1 higher than the overall geometric mean of the western German children. The higher exposure may be explained by a higher oral uptake from food and different living conditions. These children were excluded from multiple regression analysis because they were all living in the western study areas. The mean tooth lead levels ranged between 1.50 and 1.74 μg/g in the western and between 1.51 μg/g and 2.72 μg/g in the eastern study areas. Thus, they show a distribution pattern similar to blood. Blood and tooth lead levels were higher in urban than in rural areas and higher in the eastern German than in the western German study areas. With regard to the blood and tooth cadmium concentrations, no significant differences between the study areas could be found. The mean cadmium levels in blood ranged between 0.12 μg/1 and 0.14 μg/l and the mean tooth cadmium concentrations between 20.8 ng/g and 27.8 ng/g. Blood and tooth lead and cadmium levels of the eastern and western German children were thus mainly at a relatively low level in all rural and urban study areas. The study demonstrates and confirms that blood and tooth lead levels are influenced by several demographic, social, and environmental variables. The results indicate that there has been a further significant decrease of lead and cadmium exposure in western German children since our last epidemiological study carried out in the same study areas in 1985/1986.

Interrelationships between cadmium, zinc and copper in human kidney cortex

The concentrations of cadmium, copper, and zinc have been determined in tissue samples of kidney cortex collected from 399 deceased persons autopsied in Dusseldorf and Duisburg, West Germany. The mean concentrations (geometric means) were: Cd: 17.0 μg/g wet weight (range <0.4–94.3 μg/g); Cu: 1.6/ μg/g (range 0.5–8.7 μg/g); Zn: 29.1 μg/g (range 6.3–91.6 μg/g). Zinc was shown to accumulate with age in the kidney cortex in a way similar to cadmium with peak concentrations at ages between 30 and 50 years. In contrast to cadmium and zinc, the copper content did not increase with age. The calculation of the regression line between individual cadmium and zinc concentrations, expressed as μmol/g wet weight, gave a slope constant 0.723 (regression equation: ZnKc = 0.723 CdKc + 0.342; r=0.46, P <0.001), which corresponds to a somewhat less than equimolar increase of zinc. There was a significant increase of the Cd/Zn ratio in kidney cortex during the first decades of life followed by a decrease at ages over 70 year...

Blei- und Cadmiumbelastung Zähne als Indikatoren der Blei- und Cadmiumbelastung des Menschen

ZusammenfassungEs wurden die Blei- und Cadmiumgehalte in Milchschneidezähnen von Kindern aus verschiedenen Gebieten Nordrhein-Westfalens bestimmt. Die Kinder entstammten den Geburtsjahrgängen 1968–1973 und 1979–1986. Die Gegenüberstellung der Blei- und Cadmiumgehalte in den Milchzähnen dieser Kinder läßt erkennen, daß die Blei- und Cadmiumgehalte in Kinderzähnen in den 70er und 80er Jahren stark abgenommen haben. Der Rückgang beträgt im Mittel 50–60 %. Da die Blei- und Cadmiumgehalte in Zähnen als Indikatoren der Langzeit-Blei- und Cadmiumbelastung des Organismus angesehen werden können, zeigen die Untersuchungsergebnisse, daß die Blei- und Cadmiumbelastung von Kindern und wahrscheinlich auch der Bevölkerung insgesamt in den 70er und 80er Jahren erheblich abgenommen hat. Der Rückgang der Belastung setzt sich offenbar in den 90er Jahren fort. Verschiedene Studien zeigen, daß die Blei- und Cadmiumbelastung der Bevölkerung im Zuge der Industrialisierung stark zugenommen hat. Die Spitze der Belastung scheint überwunden und die Belastung nunmehr rückläufig zu sein.AbstractThe levels of lead and cadmium were determined in deciduous teeth of children from different areas of Northrhine-Westfalia, Germany. The children were born in 1968–1973 and 1979–1986. The levels of lead and cadmium in deciduous teeth show a significant decrease within this time interval. Lead decreases about 50 %, cadmium about 60 %. Since tooth lead and tooth cadmium may be used as indicators of the lead and cadmium body burden, the results of this study indicate a significant decrease of population exposure to lead and cadmium in West-Germany during the past 20–25 years, which is a consequence of pollution control and the increasing use of unleaded fuel.

Chapter 18 Lead

Publisher Summary This chapter discusses the problems of determination of lead in whole blood (PbB) as it is considered to be the best indicator of current lead exposure in humans and mammals. The techniques and problems of lead determination in other biological matrices, such as teeth, bones, plant, and animal tissues are also reviewed. The determination of PbB is of prime importance with respect to the diagnosis of lead poisoning and to the assessment of hazardous conditions, both in occupationally exposed people and in the general population. Blood contains lead in three forms: a major fraction bound to erythrocytes; a protein-bound fraction in plasma; and a diffusible fraction that represents the metabolically active form of circulating blood. The PbB level as an index of the absorbed amount of lead depends on a variety of environmental factors as well as biological factors. The correct performance of PbB determination must include the correct sampling of blood; and an internal and external quality control within each set of PbB determinations. The methods used to provide accurate and precise PbB determinations in routine use include anodic stripping voltammetry (ASV), flame atomic absorption spectrophotometry (FAAS), discrete sampling FAAS, and graphite furnace AAS (GF-AAS).