XRF and TXRF techniques for multi-element determination of trace elements in whole blood and human hair samples

XRF and TXRF were established as useful techniques for multi-element analysis of whole blood and human head hair samples. Direct-XRF with different collimation units and different X-ray excitation modes was successfully used for the determination of S, P, K, Ca, Fe, and Br elements in blood samples and K, Ca, Mn, Fe elements in human hair samples. Direct analysis by TXRF was used for the determination of Rb and Sr in digested blood and human hair samples, respectively, while, the co-precipitation method using APDC for TXRF analysis was used for the determination of Ni, Cu, Zn, and Pb elements in both matrices. As a result, the improved XRF and TXRF methods were applied for multi-element determination of elements in whole blood and human hair samples in non-occupational exposed population living in Damascus city. The mean concentrations of analyzed elements in both matrices were on the reported range values for non-occupational population in other countries.     

Uranium concentration measurements in human blood for some governorates in Iraq using CR-39 track detector

The sensitive and simple technique of fission track etch has been applied to determine trace concentration of uranium in blood samples for occupational and non-occupational workers, male and female, using CR-39 track detector that is employed for registration of induced fission tracks. The results show that the highest recorded uranium concentration in human blood of workers in the ministry of Science and Technology were 1.90 ppb (male, 36 years old, 12 years' work experience, and living in Basrah governorate) and minimum concentration 0.26 ppb (female, 40 years old, 10 years' work experience, and living in Baghdad), while for non-occupational worker, the maximum uranium concentration was 1.76 ppb (female, 63 years old, and living in Al-Muthana) and minimum concentration was 0.28 ppb (female, 20 years old, and living in Baghdad). It has also been found that the uranium concentration in human blood samples of workers in the ministry of Science and Technology are higher than those of non-occupational workers, and the uranium concentrations for female workers and for non-occupational workers were higher than those for male workers and non-occupational workers.     

Biological monitoring of 3-phenoxybenzoic acid in urine by an enzyme-linked immunosorbent assay

An enzyme-linked immunosorbent assay (ELISA) method was employed for determination of the pyrethroid biomarker, 3-phenoxybenzoic acid (3-PBA) in human urine samples. The optimized coating antigen concentration was 0.5 ng/mL with a dilution of 1:4000 for the 3-PBA antibody and 1:6000 for the enzyme conjugate. Urine samples were hydrolyzed with concentrated hydrochloric acid; extracted with dichloromethane and solvent-exchanged into a methanol/buffer solution, prior to analysis in a 96-microwell plate immunoassay. Quantitative recoveries of 3-PBA were obtained for fortified urine samples by ELISA (92 ± 18%) as well as by gas chromatography/mass spectrometry (GC/MS) (90 ± 13%). The overall method precision of these samples was within ±20% for both the ELISA and GC/MS methods. Analytical results from over one hundred urine samples showed that the ELISA and GC/MS data were highly correlated, with a correlation coefficient of 0.95. At the 10 ng/mL comparative concentration level, the false positive rate was 0% and the false negative rate was 0.8% for ELISA when using GC/MS as the reference method. The ELISA method has a suitable low detection limit for 3-PBA to assess pyrethroid exposures in non-occupational settings.     

液相色谱-质谱联用法测定血液中全氟化合物

研究了快速溶剂萃取-液相色谱/质谱联用技术测定血液中PFAAs的方法。血液样品经过冷冻干燥,利用加速溶剂萃取的方法,最后使用液相色谱-质谱仪分析检测PFAAs成分。方法的回收率为74.6%~128.8%,检出限为1.10~25.1 ng/L。通过对珠江三角洲地区人群血液样本的分析,发现∑9PFAAs的浓度为26.8~557 ng/g,平均值为176±90.1 ng/g。血液中PFAAs的主要成分以PFHxA和PFOS为主,分别占血液中PFAAs浓度的20.97%和66.98%。人群血液中最常见和浓度最高的PFAAs是PFOS,而PFOA浓度相对较低。     

交河故城古车师人的线粒体DNA分析

从距今2000～2500年左右的交河故城古代人骨中提取古DNA,用4对重叠引物对线粒体基因组的调控区(363bp)进行了扩增及测序.线粒体基因组编码区的扩增片段用于限制性片段多样性分析.结果显示4个个体中具有3个DNA序列,其中来自不同墓穴的两个个体的序列相同,说明这两者间有密切的母系遗传关系.系统发育分析表明古车师的这4个个体分散分布在现代新疆维吾尔人的序列之中.从这些结果可以初步得出结论,即古车师人群并不是一个同源群体,在早期铁器时代,欧亚人群的混合就已经存在了.     

Comparison of PBDE congener profiles and concentration levels in human specimens from China and the US and identification of human exposure sources

In an effort to investigate the status of human exposure to PBDEs in China,available monitoring data in human specimens(including breast milk,serums,and blood) was collected from the general population as well as specific groups that are occupationally exposed.PBDEs exposure profiles and concentration levels were compared with their counterparts in the United States of America.It was found that PBDE burdens in general Chinese population are one order lower and have different congener profiles from that in t...     

CHARACTERISTICS OF THE CHEMILUMINESCENCE FROM THE BLOOD PLASMA OF A NORMAL HUMAN POPULATION

Oxygen-dependent chemiluminescence was detected from human blood plasma. The intensity of the chemiluminescence increased about three-fold under oxygenation and decreased almost to the background (zero) level under a nitrogen atmosphere. The blood plasma from a sample (n = 100) of donors was tested to determine the variability of several properties of the chemiluminescence in a normal population. No statistically significant difference in blood plasma chemiluminescence between genders was found, but there was a slight increase in luminescence intensity with age. However, the results were found to be dependent on a number of other factors, such as diet, smoking and the length of time between the donor's last meal and the sampling of the blood. Some of the trends in the results coincide with similar trends in the plasma lipoprotein levels and thus support the suggestion that the chemiluminescence arises from the decomposition of lipid hydroperoxides. These factors must all, therefore, be taken into account when using chemiluminescence as an indicator of illness.     

A method of identifying the blood contributor in mixture stains through detecting blood-specific mRNA polymorphism

In the past decades, messenger RNA (mRNA) biomarkers have been employed to identify the origin of body fluids in forensic medicine. We hypothesized that the polymorphism of mRNA could be applied to identify individuals in mixture samples composed of two body fluids. In this study, we selected five blood-specific mRNA biomarkers of venous blood (SPTB, CD3G, AMICA1, ANK1, and GYPA) that encompass 16 SNPs to identify the mixture contributor(s). Five specific gene markers for menstrual blood, semen, skin, saliva, and vaginal secretions were amplified and typed as body-fluid positive controls. We established the system of multiplex PCR and single base extension (SBE) reaction followed by CE. The amplicon size was between 90bp and 294bp. The peripheral blood specificity was examined against other human body fluids, including saliva, semen, skin, menstrual blood, and vaginal secretion. The 16 SNPs were peripheral blood specific and could be successfully typed in homemade mixtures which are composed of different body fluids with 1 ng peripheral blood mRNA added. This system showed a supersensitivity (1:100) in detecting the trace amount of peripheral blood mixed in other body fluids and a combined discrimination power (CDP) of 0.99929 in Chinese population. It was the first time to establish a method for identifying the blood donors and deconvoluting mixtures through detecting mRNA polymorphism with SNaPshot assay. This peripheral blood specific SNP typing system showed high sensitivity to the typing of blood source specific markers regardless of other body fluids in the mixture.     

Trace element composition of blood in adult population in Bangladesh

The trace element composition of whole blood has been investigated in adult population in Bangladesh. The population was formed of one hundred individuals randomly selected from a working community of five hundred adults. The blood samples were freeze dried and analyzed using the external beam PIXE method. In this analysis, proton beams of 2 MeV energy and about 30 nA current were used for characteristic X-ray excitation. The concentration of eight elements, K, Ca, Fe, Cu, Zn, Br, Rb and Pb were determined by comparison with a calibration obtained from NBS orchard leaves. The frequency distributions of all the elements measured are presented and the results are compared with available data. This work was supported in part by the International Atomic Energy Agency, Vienna.     

Lateral dielectrophoretic microseparators to measure the size distribution of blood cells

Lateral displacement of blood cells occurred when they were passed over a planar interdigitated electrode array placed at an angle to the direction of flow, and was determined to be a function of cell size. A simplified line charge model was used to estimate numerically the lateral displacement. Based on the size-specific lateral displacement, a lateral dielectrophoretic (DEP) microseparator was developed to measure the size distribution of blood cells using fluorescence microscopy. To determine whether the lateral DEP microseparator was useful, it was used to detect acute leukemia by measuring the size distribution of blood cells. The lateral DEP microseparator provided a practical method for continuously and simultaneously separating multi-cell populations by size from a heterogeneous cell population. In the future, sensitivity of the lateral DEP microseparator could be improved and it could be automated by integrating subsequent advanced detection technologies in a micro-format.     

A marked difference between two populations under mass screening of neonatal TSH and biotinidase activity

Health-associated reference values are universally needed in clinical chemistry. The aim of this study was to establish the reference intervals of two populations from data obtained by the mass screening of newborn babies and to demonstrate how to determine 95% confidence intervals around the lower and upper limits of reference values from values that are not normally distributed. Biotinidase activities from Belgian (n=260) and Turkish (n=328) populations were measured by fluorometric assay and expressed as 1 IU (1 nmol/(dl min). Neonatal thyroid-stimulating hormone (nTSH) values from Belgian (n=4186) and Turkish (n=1663) populations were also measured by the solid phase two-site fluoroimmunometric assay, the results were given as μU/ml blood. Transformation of data was performed for each parameter. A parametric method was used for determination of reference values of biotinidase activity and the Belgian population was significantly higher than the Turkish population. nTSH reference values were evaluated by an exact non-parametric method, but approximate calculation based on the central limit theorem was also performed for confidence intervals around the reference limits. nTSH values of the Turkish population were found to be significantly higher than for the Belgian population. Rank numbers were found by an exact non-parametric method based upon the assumption of a binomial distribution. This study shows a procedure to define the rank numbers for n>1000 and to obtain reference values with 95% confidence intervals for lower and upper reference limits. Received: 20 July 2002 Accepted: 27 July 2002 Acknowledgements We are grateful to Professor Per Hyloft Peterson, Clinical Biochemist, Odense University Hospital, for his valuable advice and criticism. Also we would like to thank John Pezzullo Associate Professor for Pharmacology and Biostatistics, at Georgetown University Medical Center, for his binomial and approximate calculations. We also want to thank Professor Fatma Kutay, Clinical Chemist, Ege University Medical School and Hospital, for her contributions. This investigation was supported in part by a short term FEBS (Federation European Biochemical Society) fellowship grant. Presented at the European Conference on Quality in the Spotlight in Medical Laboratories, 7–9 October 2001, Antwerp, Belgium Correspondence to T. Tanyal?ın     

Negative ion chemical ionization GC/MS-MS analysis of dialkylphosphate metabolites of organophosphate pesticides in urine of non-occupationally exposed subjects

Low level exposure to organophosphate (OP) pesticides can be determined by the measurement of dialkylphosphate (DAP) metabolites in urine. An analytical method is presented here which can measure the metabolites dimethyl phosphate (DMP), diethyl phosphate (DEP), dimethyl thiophosphate (DMTP), dimethyl dithiophosphate (DMDTP), diethyl thiophosphate (DETP), and diethyl dithiophosphate (DEDTP) at low levels. This was achieved by lyophilization of the urine, derivatization with pentafluorobenzyl bromide (PFBBr) and quantification by negative ion chemical ionization GC/MS-MS. The detection limits for the metabolites were 0.5 microg L(-1) DMP, 0.1 microg L(-1) DEP, 0.1 microg L(-1) DMTP, 0.04 microg L(-1) DMDTP, 0.04 microg L(-1) DETP and 0.02 microg L(-1) DEDTP. The RSD for the analytical method was 4-14% for the six metabolites. The method was used to monitor a group of non-occupationally exposed individuals in Sydney, Australia. The metabolites DMP, DEP, DMTP, DMDTP, DETP and DEDTP occurred in 73, 77, 96, 48, 100 and 2% of the samples with median values of 13, 3, 12, <1, 1 and 1 microg L(-1) respectively. The method is simple to use, sensitive and suitable for routine analysis of non-occupational exposure levels. These detection limits are between one and two orders of magnitude lower than those previously reported in the literature.     

Association between angiotensin-1 converting enzyme gene polymorphism and the metabolic syndrome in a Mexican population

Metabolic Syndrome (MS) is recognized as a cluster of cardiovascular risk factors. All components of MS have a genetic base. Genes of the renin angiotensin system are potential candidate genes for MS. We investigated whether angiotensin converting enzyme (ACE) gene polymorphism increases susceptibility to MS as an entity in a Mexican population. In a cross-sectional study, 514 individuals were studied including 245 patients with MS and 269 subjects without MS criteria. ACE gene polymorphism was detected using PCR. MS was defined according to The National Cholesterol Education Program Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (Adult Treatment Panel III) criteria, except that the raised fasting plasma glucose 相似文献   

广东乳源县瑶族人群α和β地中海贫血的分子流行病学调查

目的调查广东省乳源县瑶族人群中的α和β地中海贫血(简称地贫)的携带率、基因突变类型及其分布特征。方法连续收集905例父母双方或一方为广东省乳源县瑶族人群的新生儿脐带血及1 347例广东省乳源县瑶族人群婚检育龄成人的外周血分别进行α和β地贫调查;所有样品均进行RBC参数和血红蛋白电泳分析,对比各项检验指标。结果在905例脐带血样本中,检出Hb Bart's阳性样品52例;经基因分析,91例被确定了α地贫基因型(含92个突变等位基因,其中--SEA/43例、-α3.7/33例、-α4.2/9例、αWSα/2例、αCSα/3例、αQSα/1例)。值得注意的是,有38例-α3.7/αα和-α4.2/αα基因携带者检出自Hb Bart's阴性样品。结论研究为进行遗传咨询和制定该地区基于人群筛查的α和β地贫预防计划提供了有价值的基础资料。     

Quantitative estimation of Br, Cl, K and Na in sample blood by NAA

Summary Neutron activation analysis, using Au as flux monitor, was applied to determine the concentrations of Br, Cl, K and Na in blood of healthy male and female blood donors, selected from blood banks and hematological laboratories from different regions of Brazil. The aims of this study were to collect more reference values of the Brazilian population as well as to perform hematological investigations. The advantages as well as the limitations of using this nuclear procedure are discussed.     

Determination of fluoroacetate and fluoride in blood serum by capillary zone electrophoresis using capacitively coupled contactless conductivity detection

Fluoroacetate is a highly toxic species naturally found in plants and in commercial products (compound 1080) for population control of several undesirable animal species. However, it is non-selective and toxic to many other animals including humans, and thus its detection is very important for forensic purposes. This paper presents a sensitive and fast method for the determination of fluoroacetate in blood serum using capillary electrophoresis with capacitively coupled contactless conductivity detection. Serum blood samples were treated with ethanol to remove proteins. The samples were analyzed in BGE containing 15 mmol/L histidine and 30 mmol/L gluconic acid (pH 3.85). The calibration curve was linear up to 75 μmol/L (R2 =0.9995 for N=12). The detection limit in the blood serum was 0.15 mg/kg, which is smaller than the lethal dose for humans and other animals. Fluoride, a metabolite of the fluoroacetate defluorination, could also be detected for levels greater than 20 μmol/L, when polybrene was used for reversion of the EOF. CTAB and didecyldimethylammonium bromide are not useful for this task because of the severe reduction of the fluoride level. However, no interference was observed for fluoroacetate.     

Separation of living red blood cells by gravitational field-flow fractionation.

The field-flow fractionation technique, using the earth's gravitational field, has been applied to peripheral blood cell populations. A more or less symmetrical, gaussian-like, elution peak is generally observed for the red cell population. The bimodal cell population obtained after a massive transfusion is shown to result in a shoulder on the red blood cell elution profile. In one case where a similar shouldering peak was obtained from a non-transfused donor, the existence of an immunological double population has been demonstrated. This suggests that field-flow fractionation has some potential for complementary biomedical diagnosis.     

Application of liquid-phase microextraction and gas chromatography-mass spectrometry for the determination of polychlorinated biphenyls in blood plasma

This study investigated the feasibility of applying liquid-phase microextraction combined with gas chromatography-mass spectrometry (GC-MS) to determine polychlorinated biphenyls (PCBs) in blood plasma. An efficient and simple extraction technique has been developed for the enrichment of PCBs from human blood plasma samples using single-step liquid-phase microextraction (LPME) in conjunction with a hollow fibre membrane (HFM). An eight PCB congener mixture was spiked into 2.5 ml of blood plasma, and the solution was then adjusted to pH 10.5 with a salinity of 20% (w/v) prior to making the total volume to 5 ml with ultrapure water. The porous HFM, filled with 3 microl of organic solvent, was then immersed into the solution, which was continuously agitated at 700 rpm for 30 min. Extract (1 microl) containing the pre-concentrated analytes was then injected into a GC-MS without further pre-treatment. Using an optimised extraction procedure, a large enrichment factor of the analytes, i.e. up to 241-fold was achieved in 30 min. The procedure resulted in a relative standard deviation of < 11% (n = 6), and a linear calibration range from 2.5 to 150 microg/l (r > 0.999), and detection limits between 0.07 and 0.94 microg/l, respectively. To demonstrate the feasibility of the procedure, PCB concentrations were determined in actual blood samples collected from the local population in Singapore using the optimised LPME technique.     

Validation of the CALUX bioassay for PCDD/F analyses in human blood plasma and comparison with GC-HRMS

Following the dioxin crisis of 1999, several studies were conducted to assess the impact of this crisis on the dioxin body burden in the Belgian population. The Scientific Institute of Public Health identified a population from whom plasma samples were available and from whom, during the follow up survey, plasma samples were obtained in 2000. In total, 496 samples were collected for GC-HRMS and CALUX analyses to verify statistical assessment conclusions. This study was seen as an opportunity to validate the CALUX bioassay for biological sample analysis and to compare toxic equivalency (TEQ) values obtained by the reference GC-HRMS technique and by the screening method. This article focuses on the validation results of the CALUX bioassay for the analyses of the dioxin fractions of blood plasma. The sample preparation is based on a liquid–liquid extraction, followed by an acid silica in series with an activated carbon clean-up. A good recovery (82%) and reproducibility (coefficient of variation less than 25%) were found for this method. Based on 341 plasma samples, a significant correlation was established between the bioassay and chemical method (R = 0.64). However, a proportional systematic error was observed when the results obtained with the CALUX bioassay were regressed with the results from the GC-HRMS analyses. The limit of quantification (LOQ) used to calculate TEQ values from the GC-HRMS determinations, the use of the relative potency values instead of the toxic equivalent factor and the potential of CALUX bioassay to measure all compounds with affinity for the AhR may partly explain this proportional systematic error. Nevertheless, the present results suggest that the CALUX bioassay could be a promising valid screening method for human blood plasma analyses.     

Trace analysis of total fluorine in human blood using combustion ion chromatography for fluorine: a mass balance approach for the determination of known and unknown organofluorine compounds

The number of perfluorochemicals (PFCs) that have been found in biological and environmental matrices is increasing as analytical standards and methods evolve. Perfluorooctanesulfonate (PFOS) and perfluorooctanoate (PFOA) constitute only a fraction of the total suite of PFCs found in environmental and biological matrices. A robust method and approach is needed to evaluate the mass of fluorinated compounds in biological matrices. In this study, we developed a method to measure total fluorine (TF) and organic fluorine (TOF) in human blood matrices using combustion ion chromatography (CIC). Blood matrices (whole blood, serum, and plasma) were analyzed in bulk to determine TF. An aliquot of the blood was also extracted with organic solvents such as methyl-tert-butyl ether (MTBE) and hexane, and organic and aqueous extracts were separated, to fractionate organofluorines from inorganic fluorine. The organic layer was analyzed for TF by CIC, and for known PFCs by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). PFCs measured by HPLC-MS/MS accounted for >80% of the TF in the organic fraction. The aqueous fraction contained inorganic fluorine and other non-extractable organofluorines. However, in the bulk sample, fluoride and non-extractable organofluorines accounted for >70% of the TF in blood samples from the general population. In occupationally exposed individuals, known organofluorines accounted for a major proportion of the TF. These results suggest the existence of yet uncharacterized fluorine fraction in human blood. Further studies are needed to characterize the aqueous fraction that contains inorganic fluorine and non-extractable forms of fluorine.