Determination Of Lead In Blood Research Articles

Determination of lead and other trace element species in blood by size exclusion chromatography and inductively coupled plasma/mass spectrometry

The combination of liquid chromatography and inductively coupled plasma/mass spectrometry (ICP/MS) was employed in an exploratory study to determine lead and other trace element species in blood components. In human blood serum, lead was found in at least three molecular weight fractions at greater than 600,000, 260,000, and 140,000. The major part of lead was coincident with the main copper signal at a molecular weight of 140,000. This fraction, binding both copper and lead, was proven to be ceruloplasmin by the application of an immunological reaction prior to chromatographic separation. In rat serum, lead could be detected in four fractions with molecular weights of greater than 600,000, 400,000, 145,000, and 11,000. In human red blood cell hemolysate, the major fraction of lead was found at 250,000, with minor fractions at 140,000 and at 30,000 together with iron in hemoglobin and zinc in carbonic anhydrase. In rat red blood cell hemolysate, lead was detected at greater than 600,000, 145,000, 30,000, and 11,000. Lead isotope ratios were determined in lead binding protein fractions with a precision of +/- 10%. The detection limit for lead in protein fractions was 0.15 micrograms.L-1.

The effect of oxygen addition on the determination of cadmium and lead in blood and foods by graphite furnace atomic absorption spectrometry

It is well known that in the analysis of low temperature vaporized metal elements such as cadmium and lead, a high ashing temperature causes a loss of the target atoms at the ashing stage, while low ashing temperature causes incomplete decomposition of organic components in the sample. In order to solve these problems, the effect of oxygen addition on determination of cadmium and lead in blood and foods was studied. Oxygen was introduced into the atmosphere in the graphite furnace at the beginning of ashing stage for 20 seconds at 0.5 l/min. Relation between ashing temperature and sensitivity was examined, and the oxygen addition minimized signal depression by the sample matrix. It can be concluded that the addition of oxygen at the ashing stage not only reduces the background absorption, but also suppress the volatilization of target atoms at the ashing stage by the formation of their oxides.

Direct determination of lead in whole human blood by total reflection X-ray fluorescence spectrometry

A new and fast sample preparation technique was developed for the analysis of lead in whole human blood by total reflection X-ray fluorescence spectrometry. A 2-μl drop of fresh blood was pipetted onto a quartz glass reflector, dried and ashed in a low-temperature oxygen plasma asher operated at 50 mW for 18 minutes. The residue, consisting mainly of metals and being free of low Z elements, was exposed to an X-ray beam coming from a total reflection system with a cut-off reflector. This system gives a significant background reduction. The detection limit achieved for Pb is about 0.03 μg ml for 1000 s measuring time. Whole blood samples were obtained from donors occupationally exposed to lead contamination in a car battery factory and from unexposed donors. Blood lead concentrations found in these individuals are reported.

Study of environmental pollutants in and around the city of Lahore I. Determination of lead in blood of various population groups

Lead concentrations in 102 blood samples collected from seven different population groups living in and around the city of Lahore were determined. Gender differences in blood lead were statistically insignificant for normal males and normal females and also for male and female cancer patients. The differences between exposed male industrial workers and exposed females were statistically significant ( P = 0.05). No correlation was observed between age and blood lead for normal males and cancer patients of both sexes. Blood lead levels in the male groups were generally higher than in the corresponding female groups. Much higher blood lead concentrations for cancer patients of both sexes, i.e. 69.63 μg dl −1 for males and 52.41 μg dl −1 for females, were observed.

Determinants of elevated blood lead during pregnancy in a population surrounding a lead smelter in Kosovo, Yugoslavia

We are prospectively examining the relation between environmental lead exposure and pregnancy outcome in cohorts of women exposed to a wide range of air lead concentrations. Titova Mitrovica, Yugoslavia, is the site of a large lead smelter, refinery, and battery factory. At midpregnancy, 602 women in T. Mitrovica and 900 women in Pristina, a non-lead-exposed control town, were interviewed. Blood was obtained for blood lead (PbB), hemoglobin, erythrocyte protoporphyrin, and serum ferritin measurements. Women were seen again at delivery, at which time maternal and umbilical cord blood samples were obtained. While many demographic and social characteristics were similar across the two towns, women in Pristina were more likely to report employment outside the home, cigarette smoking, and alcohol use during pregnancy. As expected, PbB levels were substantially higher in the smelter town. At midpregnancy, PbB geometric means were 17.1 micrograms/dL in T. Mitrovica and 5.1 micrograms/dL in Pristina; 86% of the pregnant women in T. Mitrovica, compared to 3.4% of those in Pristina, had PbB levels greater than 10 micrograms/dL. Within T. Mitrovica, distance between the home and the smelter was the most important predictor of PbB at mid-pregnancy and delivery. Husband's employment in the lead industry was associated with a significant increase in maternal PbB levels independent of place of residence. Higher maternal serum ferritin concentrations were associated with lower PbB levels, suggesting that dietary iron inhibits lead absorption. Overall, the placenta was a poor barrier to lead; the relationship between maternal PbB and umbilical cord PbB was linear across a wide range of PbB levels.

Determinants of Elevated Blood Lead during Pregnancy in a Population Surrounding a Lead Smelter in Kosovo, Yugoslavia

Determinants of Elevated Blood Lead during Pregnancy in a Population Surrounding a Lead Smelter in Kosovo, Yugoslavia

Direct determination of lead in human blood and selenium, cadmium, copper, zinc in serum by electrothermal atomic absorption spectrophotometry using Zeeman effect background correction

The procedure for the direct determination of lead in human blood and selenium, cadmium, copper and zinc from human blood serum with micro quantities of the samples are described using electrothermal atomic absorption spectrophotometry with L'vov platform and Zeeman correction. No predigestion or extraction procedures are required. The analyses are performed by simple dilution of the specimen with Triton X-100 and/or proper matrix modifier. The method of standard additions and peak area measurement are used for quantitation. L'vov platforms have been used for all elements except cooper. Use of micro quantity of the sample, better reproducibility, low detection limit and possibility of analyzing a large number of samples per day made this technique particularly suitable as routine analytical procedure in clinical laboratory. The procedures for determination of the metal ions are applied on sixty normal persons and twenty-two cardiomyopathy patients to find any correlation.

Identification of potential environmental sources of childhood lead poisoning by inductively coupled plasma mass spectrometry. Verification and case studies

The isotopic determination of lead in blood and environmental materials by inductively coupled plasma mass spectrometry was used for the identification of potential sources of childhood lead poisoning. Sample preparation methods for blood, dust, paint, sediment and soil were evaluated and the recovery of total lead and the lead isotope composition of samples were determined. Verification of the measurement accuracy and precision was obtained for standard reference materials and a number of practical cases of childhood lead poisoning from an unknown source were studied.

Direct Determination of Lead in Whole Blood Using Electrothermal Vaporization Inductively Coupled Plasma Atomic Emission Spectrometry

Abstract A carbon rod atomizer was used for sample introduction into a commercial inductively coupled plasma for the determination of lead in whole blood. Samples of known lead concentration were either treated with Triton-X or nitric acid or diluted 1+5 with distilled water and analyzed by comparison against graphs obtained using aqueous solutions and using the standard additions method. Both approaches produced similar results indicating no appreciable matrix influence. The Pb concentration values obtained were in close agreement with those previously determined by ETA-AAS, Delves′ cup-FAAS and anodic stripping voltammetry. Signal integration and careful selection of the measurement period were critical to obtain accurate results. Derived concentrations were shown to be essentially independent of the heating rate of the vaporization unit and the length of tubing used to transport the material into the plasma. Using a 1 μg ml−1 lead aqueous standard, a signal to background ratio of 5.5 was obtained under optimized conditions. Relative standard deviations of the blank and the analytical signal were 0.2 and 1.8%., respectively. An aqueous solution detection limit of 0.007 μg ml−1 was calculated for lead.

Determination of lead in blood by graphite furnace atomic absorption spectrometry — A critique

Graphite furnace atomic absorption spectrometry (GFAAS) is increasingly becoming the method of choice for the determination of Pb in blood. The major GFAAS methods that have been published to date include: (i) direct introduction of the sample into the furnace; (ii) dilution with water, Triton X-100 or acid; (iii) deproteinization with nitric acid; (iv) matrix modification; and (v) solvent extraction. This review focuses on the difficulties associated with each of these methods, and highlights recent attempts to overcome matrix interferences and improve the accuracy and precision of Pb determination in blood using modern furnace technology, especially the stabilized temperature platform furnace.

The effect of lead on thyroid function in children

Exposure to inorganic lead has been associated with impaired uptake of iodine by the thyroid as well as depressed estimated free thyroxine levels in occupationally exposed adults. Consideration of the serious consequences of impaired thyroid function in young children prompted investigation of the effects of lead on thyroid function in children. Blood lead determinations and thyroid function tests were performed on 68 children examined at a hospital outpatient pediatric clinic. Serum thyroxine (T4) and free thyroxine (FT4) levels were within the normal range for all patients. No statistically significant relationship was found between lead levels and T4 or FT4 levels. We conclude that lead is unlikely to have a clinically significant effect on thyroid function in children exposed in inner cities at prevailing levels.

Blood lead determinants of a population living in a former lead mining area in Southern Scotland

The impact of high environmental lead levels on public health is currently under much debate. Such a situation exists in two former lead mining villages set in the Southern Uplands of Scotland, where the environment is heavily contaminated through past mining activity. A survey was conducted based on representative samples of male and female adults and of all children living in the area, to examine the distribution of blood lead levels and to compare this with the distribution in residents in a control area. Possible routes of exposure including the determination of lead in domestic water, in house dust, in airborne dust, on food preparation surfaces, on hands, in garden soils and through home grown vegetable consumption were investigated. The results indicate that there is a general increase in lead exposure in environmental variables in the contaminated area, while blood lead levels show an excess of between 45 and 70 percent compared with the control. The determinants of blood lead are discussed through correlation and multiple regression analysis.

Determination of lead in whole blood by electrothermal atomisation atomic absorption spectrometry using tube and platform atomisers and dilution with Triton X-100

The determination of lead in whole blood by electrothermal atomisation atomic absorption spectrometry using a Varian Model AA875 atomic absorption spectrometer coupled to a Varian Model GTA-95 graphite furnace is reported. An evaluation was undertaken to determine whether the use of (NH4)2HPO4 was beneficial when using tube and platform atomisers. Optimisations of the furnace heating conditions and of the best absorbance mode and sensitivity in both systems were also undertaken. The analysis of a target standard showed that it was possible to determine lead in blood by simple dilution with Triton X-100 using platform atomisation and the peak-area calculation mode. Calibration was carried out by direct comparison with linear working graphs prepared from aqueous standards.

Assessment of various designs of L'vov platform graphite tube atomisers

Several alternative designs of L'vov platform graphite tube atomiser have been assessed by their performance under routine analytical conditions with an established electrothermal atomisation atomic absorption spectrometric method for the determination of lead in whole blood. Using the delay in appearance time of the lead atomic signals and analytical sensitivity as figures of merit, the alternative designs do not perform as well as a solid pyrolytic graphite L'vov platform placed in a non-grooved pyrolytic graphite coated graphite tube. This configuration, which appears to be optimum for current, commercially available electrothermal atomisers, fails to give isothermal atomisation, the attainment of which will require the further development of constant-temperature atomisers.

Effect of oxygen gas as a matrix modifier on direct determination of cadmium and lead in blood and food samples by graphite furnace AAS.

An addition of oxygen gas to graphite furnace during the first ashing stage (20 s, 0.51 min-1) of AAS determination of Cd and Pb greatly decreased the background absorption due to sample matrices such as milk, orange juice and blood. In case of Pb determination, the intensity of background absorption due to blood matrix decreased to one-tenth of that without oxygen gas treatment. The addition of oxygen gas also prevented the signal depression of Cd and Pb by the sample matrices.

Determination of lead in whole blood by graphite furnace atomic absorption spectrometry with matrix modification

A graphite furnace atomic absorption spectrometric (GFAAS) method for the determination of lead in whole blood specimens has been developed. Blood was diluted ten-fold with 0.01%V/V Triton X-100 solution; 10 µl of diluted blood and 10 µl of a matrix modified mixture [0.6%m/VNH4H2PO4 and 0.15%m/VMg(NO3)2 in 0.01 M HNO3] were automatically injected in sequence into pyrolytic graphite coated graphite tubes. For comparison purposes, atomisation from a L'vov platform was also carried out. A 0.2-nm slit width was required in order to overcome spectral interference. The characteristic masses were 23 and 15 pg of Pb per 0.0044 A s for the pyrolytic graphite coated tube and L'vov platform, respectively. In the diluted solutions, the detection limits (3σ) for the method described were 1.2 µg l–1 of Pb (pyrolytic graphite tube) and 0.7 µg l–1 of Pb (L'vov platform). The accuracy of the method was tested using NBS SRM 955 (a mean relative error of ca. 1% was obtained) and recovery studies were undertaken (average recoveries were 102%, range 95–105%). The precision was acceptable and an approximate standard deviation (SD) of 0.8 µg l–1 of Pb was found for both within- and between-(day to day) run precision. The proposed method was used in studies of populations with a low risk of lead intoxication by environmental and/or occupational exposure; a mean (± SD) whole blood lead concentration of 110 ± 11 µg l–1(n= 309 individuals) was found. The method was free from interference, reliable and reproducible.

Determination of lead in blood — An interlaboratory study

An international co-operative blood-Pb interlaboratory study and a Canadian co-operative blood-Pb interlaboratory study were conducted using freeze-dried bovine blood samples with different endogenous Pb levels. The samples were prepared from whole blood of a nonexposed cow and another fed with a single dose of lead acetate. The mean values computed for the two samples analyzed by 25 international participants from 13 countries were 55 and 250 μg Pbl −1, respectively. These results showed a positive bias of 10% for the low level and 9% for the high Pb level with respect to the reference values obtained by isotope dilution mass spectrometry. In the case of the Canadian interlaboratory survey the mean values computed for the two samples analyzed by the 12 participants were 40 and 229 μg Pbl −1, respectively. These results showed a negative bias of 20 and 0.4% in relation to the target values of 50 and 230 μg Pbl −1, respectively. Despite such a bias, the data, on the whole, were of acceptable precision and accuracy when compared with previous interlaboratory blood-Pb surveys.

Microsampling technique and determination of blood lead by zeeman atomic absorption spectrophotometry

Quality control materials and participation in proficiency testing programmes were used for assessing the long-term performance of our blood lead analysis. The accuracy and precision of the blood controls, Metals 1 and 2 from the Behring Institute, were evaluated over a 1-year period. The accuracy of the method was also monitored by the Centers for Disease Control (CDC) Blood Lead Proficiency Testing Programme over a 3-year period. Nearly 85% (28 out of 33 samples) of our results were within ± 5% of the CDC reference values. There were excellent correlations between our results and the target values of several proficiency testing samples, with correlation coefficient values of 0.9959–0.9970. The method was used for the screening of blood lead in children in conjunction with microsampling techniques.

Determination of lead in blood using flow injection and a nebuliser interface for flame atomic absorption spectrometry.

An improved system for the determination of lead in blood by flame atomic absorption spectrometry has been developed. The system is based on flow injection, a nebuliser interface and a computer signal evaluation system. The system improves the detection limit 12-fold compared with that obtained by unmodified instrumentation. A detection limit of 0.06 µM was obtained using a 10-year-old instrument. With a relative standard deviation of 5% at normal lead levels in blood, even small changes in the lead concentration can be determined with adequate precision and accuracy.

Quality control samples for the determination of lead and cadmium in blood, feces, air filters, and dust

Quality control samples for the determination of lead and cadmium in blood, feces, air filters, and dust have been prepared within the UNEP/WHO Human Exposure Assessment Location (HEAL) Project. The preparation is given in detail. Problems related to sample preparation and reference values are discussed.