Pb In Biological Samples Research Articles

An Eco‐Friendly Approach for Determination of Lead in Biological Samples after Deep Eutectic Solvent Extraction

AbstractThe present research proposes investigating deep eutectic solvents for extracting Pb from biological samples for further determination by GF AAS. Among the synthesized solvents, the DES obtained from choline chloride and oxalic acid (ChCl : Ox) in a molar ratio 1 : 1 presented the best lead (Pb) extraction efficiency. Subsequently, it was characterized by Fourier Transform Infrared Spectroscopy (FTIR). For extraction, the optimized conditions were: 40 mg of sample, 400 μL of DES (ChCl : Ox) added, and 30 min at 95±5 °C. The supernatant was diluted, and the Pb was determined by GF AAS. The optimized instrumental conditions for Pb determination were 900 °C and 2100 °C, pyrolysis and atomization temperatures, respectively, using Pd as a chemical modifier. The limits of detection and quantification were 0.04 and 0.12 μg g−1, respectively. The method's accuracy was evaluated by analyzing the certificate reference materials, and good agreement was obtained between the determined and certificate values. The greenness of the proposed method was evaluated by green star and eco‐scale metrics. Thus, the proposed method proved simple, efficient, and eco‐friendly for determining Pb in biological samples.

A Portable Microplasma Optical Emission Spectrometric Device with Online Digestion Function for Field and Sensitive Determination of Lead in Biological Samples.

Accurate detection and screening of Pb in biological samples is helpful to assess the risk associated with lead pollution to human health. However, conventional atomic spectroscopic instruments are bulky and cumbersome, requiring additional sample pretreatment equipment, and difficult to perform field analysis with. Herein, a portable point discharge (PD) microplasma-optical emission spectrometric (OES) device with online digestion function is designed for field and sensitive determination of lead in biological samples. With rice as a model, online digestion of a batch of six 50 mg samples can be achieved in the HNO3 and H2O2 system within 25 min by a temperature control and timing module. Compared to the conventional microwave digestion, the digestion efficiency of this device reaches 97%. Pb in digestion solution is converted into volatile species by hydride generation (HG) and directly introduced into PD-OES for excitation and detection by a self-designed rotatable and telescopic cutoff gas sampling column. Six samples can be successively detected in 2 min, and argon consumption of the whole process is only <800 mL. Under the optimized conditions, the detection limit of Pb is 0.018 mg kg-1 (0.9 μg L-1) and precision is 3.6%. The accuracy and practicability of the present device are verified by measuring several certified reference materials and real biological samples. By virtue of small size (23.5 × 17 × 8.5 cm3), lightweight (2.5 kg), and low energy consumption (24.3 W), the present device provides a convenient tool for field analysis of toxic elements in biological samples.

Effect Of Lead On The Skin And Health Of Female Dermatitis Patients Through Cosmetics.

Cosmetics have been a part of routine body care not only for the upper classes but also for the middle and lower classes since the dawn of civilization. Cosmetic formulations are in more demand as the public's interest in skin whitening grows. The contamination of cosmetics with heavy metals is a major concern as they containing heavy metals and pose a major risk to human health. This study looks in to the effects of Lead on human skin. In this cross sectional study different products were examined. The matrices (scalp hair, blood, serum and nails) of reference and dermatitis cosmetic female patients (seborrhoeic dermatitis, rosacea, allergic contact dermatitis, and irritant contact dermatitis) and cosmetic samples were used in a 2:1 mixture of HNO3 (65%) and H2O2 (30%), and oxidation was performed using a microwave. The oxidized beauty and biological specimen underwent electrothermal atomic emission spectrophotometry after microwave-assisted acid digestion. The validity and precision of the methodology were verified using certified reference materials. Cosmetic products (lipstick, face powder, Eye Liner and Eye shadow) of different brands contain Pb concentrations in the ranges of 50.5-120 μg/g, 14.6-30.7 μg/g, 2.87-4.25 μg/g and 15.3-21.6 μg/g, respectively. In the present study, cosmetic products (lipstick (N=15), face powder (N=13), eye liner (N=11), eye shadow (N=15) and female patients with dermatitis (N=252) residing in Hyderabad city, Sindh, Pakistan, was investigated. The outcome of this investigation showed significantly higher levels of Pb in biological samples (blood and scalp hair) of different types of female dermatitis patients than in reference subjects (p<0.001). The cosmetic products, especially with regard to heavy metals adulteration, are in use by the female population.

Calcium and Lead Levels in the Biological Samples and Their Effect on the Biochemical Parameters of Indoor and Outdoor Workers of Five Zonal Areas of Coal Mining Field

Workers of the Lakhra coal mining Sindh Pakistan were affected by a multi-factorial exposure of heavy metals. The prevalence of lead (Pb) exposures in work-related symptoms among workers of indoor and outdoor mining of Lakhra coal mining was evaluated in detail. The biological samples (scalp hair and blood) of 270 workers of Lakhra coal mining {official and control subjects} (indoor and outdoor) 18 to 55 years age group and 70 referent subjects of same age-groups were examined. The biological samples (blood and scalp hair) of workers of Lakhra coal mining and referent subjects were analyzed for calcium (Ca) and lead (Pb). Flame atomic absorption spectrometry was applied for the determination of the Ca in digested samples of studied subjects by the microwave oven whereas, the Pb contents were measured by electrothermal atomic absorption spectrometry. The validity of the methodology was checked by using the certified human hair material (BCR 397) and lyophilized human blood (Clincheck). The results indicated the higher contents of Pb in biological samples of indoor and outdoor mining workers than referents. However, the levels of Ca were found to be lower in indoor and outdoor mining workers than those of referents. It can be concluded that immediate action should be taken by recommended authorities to improve the ventilation and hygiene practices inside the industries, mines, and other workplaces.

Distribution of arsenic, cadmium, lead, and nickel levels in biological samples of Pakistani hypertensive patients and control subjects.

The abnormal metabolism of metal ions plays an important role in health and disease conditions, and studies about them have been attracting significant interest. The aim of our study was to assess the toxic elements arsenic (As), cadmium (Cd), nickel (Ni), and lead (Pb) in biological samples (scalp hair, blood, urine) of 387 hypertensive males and females, aged between 30 and 60 years, from an urban population together with 439 non-hypertensive subjects, of the same age group and residential areas. The element concentrations were measured by means of an electrothermal atomic absorption spectrophotometer after microwave-induced acid digestion. The validity and accuracy was checked by conventional wet acid digestion method and using certified reference materials. The overall recoveries of all elements were found in the range of 96.8 - 99.4% of certified values. The results indicated significantly higher levels of As, Cd, Ni, and Pb in the biological samples (scalp hair, blood and urine) of hypertensive patients, when related to controls of both genders. The high exposure of toxic elements may be synergistic with risk factors associated with hypertension. These data present guidance to clinicians and other professionals who will be investigating the toxicity of heavy elements in biological samples (scalp hair and blood) of hypertensive patients.

Evaluation of electrothermal vaporization as a sample introduction technique for the determination of trace elements in biological samples by inductively coupled plasma mass spectrometry, following dispersive liquid–liquid microextraction

This work describes the method development process involved in the determination of Ag, Cd, Cu and Pb in biological samples by electrothermal vaporization inductively coupled plasma mass spectrometry (ETV-ICP-MS), following dispersive liquid–liquid microextraction (DLLME). The parameters associated with DLLME such as HNO3 and diethyldithiophosphate (DDTP) concentrations, as well as the volumes of disperser (ethanol) and extracting (chloroform) solvents, were evaluated. The ICP-MS operating parameters (carrier gas flow rate and RF power) were also optimized. Several distinct approaches involving investigation on chemical modifiers (W, Ru, Pd and combinations), aerosol carriers (Na2SO4, ascorbic acid and diethyldithiophosphate – DDTP) and the effect of insertion of a L'vov platform on the transport efficiency from the ETV to the ICP and overall analytical performance were evaluated. The results suggest that the use of a platform and chemical modifiers lead to increased thermal stability, although the sensitivity is generally reduced when compared to the absence of modifiers and wall vaporization. Several calibration approaches were evaluated, including the combination of chemical modifiers and the use or absence of a L'vov platform inside the graphite tube. Accurate results were achieved for all elements upon the use of palladium as the aerosol carrier in combination with W and Ru as permanent chemical modifiers, demonstrating that the effective transportation of the analytes and equalization of the transport efficiency between samples and calibration solutions are carrier-dependent. To verify the accuracy of the proposed methodology, four certified reference biological materials were analyzed, with good agreement between certified and determined values. ‘Real’ samples were also analyzed following the optimized procedure. The proposed method resulted in detection limits between 0.001 and 0.09 μg g−1 and enhancement factors between 35 and 59, with appreciable analytical sensitivity.

Evaluation of Status of Arsenic, Cadmium, Lead and Zinc Levels in Biological Samples of Normal and Arthritis Patients of Age Groups (46 - 60) and (61 - 75) Years

Arthritis is a chronic inflammatory disease resulting in inflammation of diarthrodial joints (particularly joints of hands, wrists, feet, knees, ankles, and shoulders), manifested by swelling and functional impairment. This study was designed to evaluate the levels of the toxic elements arsenic (As), cadmium (Cd), and lead (Pb) and correlate those with the essential trace element zinc (Zn) in biological samples (scalp hair, blood, and urine) of arthritis patients, in two age groups (46 - 60 and 61 - 75) of both genders. For comparison purposes all three biological samples were collected from gender- and age-matched non-arthritic subjects as referents. The As, Cd, and Pb in biological samples were analysed by electrothermal atomic absorption spectrometry, prior to microwave assisted acid digestion. The level of Zn was determined by flame atomic absorption spectrometry. The validity and accuracy of the methodology was checked by using Certified Reference Materials (CRM) from the Community Bureau of Reference (BCR) of the Commission of the European Community and with those values obtained by conventional wet acid digestion method on the same CRMs. The results of this study showed that the mean values of As, Cd, and Pb were higher in blood, scalp hair, and urine samples of arthritis patients as compared to those values obtained in age-matched referent subjects. The concentration of Zn was lower in the biological samples of rheumatoid arthritis patients of both genders with respect to non-arthritic subjects. The urinary levels of the elements studied were found to be higher in the arthritis patients than in the age-matched healthy referents (p < 0.001). An inverse correlation was observed between Zn and toxic elements in biological samples of arthritis patients (r = 0.612 - 0.754). Intake of certain antioxidant micronutrients, particularly a zinc supplement, may protect against the development of rheumatoid arthritis.

Palladium nanoparticles as the modifier for the determination of Zn, As, Cd, Sb, Hg and Pb in biological samples by ultrasonic slurry sampling electrothermal vaporization inductively coupled plasma mass spectrometry

Palladium nanoparticles (Pd-NPs) were used as the modifier for the determination of Zn, As, Cd, Sb, Hg and Pb in biological samples by ultrasonic slurry sampling electrothermal vaporization inductively coupled plasma mass spectrometry (USS-ETV-ICP-MS). The preparation and characterization of palladium nanoparticles (Pd-NPs) is described. Compared to traditional Pd aqueous solution, better ion signals were obtained when Pd-NPs was used as modifier. The influences of instrument operating conditions and slurry preparation on the ion signals were reported. The introduction of dry aerosol with ETV sampling device alleviated the spectral interferences effectively. This method has been applied for the determination of Zn, As, Cd, Sb, Hg and Pb in NIST SRM 1568a Rice Flour and SRM 1573a Tomato Leaves reference materials and two biological samples obtained locally. The analysis results of the reference material agree with the certified values. The results for the real world samples were also found to be in good agreement with the pneumatic nebulization ICP-MS results of the sample solutions. The method detection limits estimated from standard addition curves are in the range 1.9–3.6, 0.2–0.4, 0.5–0.8, 0.1–0.2, 0.4–0.8 and 0.4–0.6 ng g−1 for Zn, As, Cd, Sb, Hg and Pb, respectively, in original samples.

Status of Toxic Metals in Biological Samples of Diabetic Mothers and Their Neonates

The mechanism of transport of trace elements from the mother to the newborn is still not well known. The aim of present study was to compare the status of trace toxic elements, arsenic (As), cadmium (Cd), and lead (Pb) in biological samples (whole blood, urine and scalp hair) of insulin-dependent diabetic mothers (age ranged 30-40) and their newly born infants (n = 76). An age and socioeconomics matched 68 nondiabetic mothers and their infants, residing in the same locality, who were selected as referents. The elemental concentrations in all three biological samples were determined by an electrothermal atomic absorption spectrometer, prior to microwave-assisted acid digestion. The mean values of As, Cd, and Pb in all biological samples of diabetic mothers and their infants were significantly higher as compared to the referent mother-infant pair samples (p < 0.01). The high levels of As, Cd, and Pb in biological samples of diabetic women may play a role in the pathogenesis of diabetes mellitus and impacts on their neonates.

Determination of Cd, Co, Ni and Pb in biological samples by microcolumn packed with black stone (Pierre noire) online coupled with ICP-OES

A simple and sensitive method using microcolumn (20-mm length × 2.0-mm i.d.) packed with black stone (Pierre noire) for the separation/preconcentration of Cd, Co, Ni and Pb in biological samples prior to their online determination by inductively coupled plasma optical emission spectrometry (ICP-OES) has been developed. Optimal experimental conditions including pH, eluent concentration and volume, sample volume and sample flow rate were investigated and established. The adsorption capacity of black stone for Cd, Co, Ni and Pb were found to be 23.4, 21.2, 18.1 and 22.2 mg g −1, respectively. With a preconcentration time of 72 s and an elution time of 4 s, an enrichment factor of 20 and a sampling frequency of 25 h −1 were obtained. The detection limits corresponding to three times the standard deviations of the blank for Cd, Co, Ni and Pb were found to be 0.3, 0.4, 0.4 and 1.1 ng mL −1. The precision for seven replicate determinations of Cd, Co, Ni and Pb gave relative standard deviations (RSDs) of 5.9, 4.8, 2.7 and 1.1%, respectively ( n = 7, C = 10 ng mL −1). The method was validated with certified reference material GBW09103 human urine and the results obtained were in good agreement with the certified values. The method was also applied to the determination of the target analytes in biological samples with satisfactory results.

Single drop microextraction combined with graphite furnace atomic absorption spectrometry for determination of lead in biological samples

Single drop microextraction combined with graphite furnace atomic absorption spectrometry is introduced for the determination of trace lead in water samples. A drop of 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone (PMBP) dissolved in benzene was held at the tip of a microsyringe and immerged into the sample solution which was stirred, the solvent drop interacts with the sample solution, and the analyte was extracted into the drop and concentrated. After extracting for a period of time, the drop was retracted into the microsyringe and directly injected into graphite furnace for GFAAS determination of Pb. Several factors affecting the extraction efficiency, such as pH of sample solution, drop volume, stirring rate and extraction time, were optimized. Under the optimized conditions, an enhancement factor of 16 was achieved, and the detection limits for Pb were 25 ng L−1. The relative standard deviation for seven replicate determination of 10 ng mL−1 Pb was 6.1%. The method was applied to determine trace Pb in biological samples with satisfactory results.

MPTS-silica coated capillary microextraction on line hyphenated with inductively coupled plasma atomic emission spectrometry for the determination of Cu, Hg and Pb in biological samples

A novel sol–gel 3-mercaptopropyltrimethoxysilane (MPTS) modified silica coating was developed for capillary microextraction (CME) of trace Cu, Hg and Pb prior to their on line determination by inductively coupled plasma–atomic emission spectrometry (ICP–AES). This organic–inorganic hybrid coating was in situ created on the inner walls of fused silica capillary using a sol solution containing TMOS (tetramethoxysilane) as a precursor, MPTS as a co-precursor, ethanol as the solvent and hydrochloric acid as a catalyst. The structure of the capillary coating was characterized by FT-IR spectroscopy, Raman spectroscopy, SEM and TEM. The factors affecting on the capillary microextraction of analytes such as pH, sample flow rate and volume, elution solution and interfering ions had been investigated, and the optimized experimental parameters were obtained. Under the optimized conditions, the absorption capacity of MPTS-silica coated capillary was found to be 1.17, 1.96 and 1.19 μg m −1 for Cu, Hg and Pb, and the limits of detection were as low as 0.17 0.22 and 0.52 ng mL −1, respectively. With a sampling frequency of 12 h −1, the relative standard deviations (R.S.D.s) were 4.2, 2.6 and 3.8% (C=4 ng mL −1, n = 7, sample volume = 1 mL) for Cu, Hg and Pb, respectively. The proposed method had been successfully applied to the determination of Cu, Hg and Pb in human urine, human serum and preserved egg. To validate the proposed method, certified reference materials of BCR151 milk powder, GBW07601 (GSH-1) human hair, GSBZ 50016-90 and GSB 07-1183-2000 water samples were analyzed and the determined values were in a good agreement with the certified values.

Sol‐gel zirconia coating capillary microextraction on‐line hyphenated with inductively coupled plasma mass spectrometry for the determination of Cr, Cu, Cd and Pb in biological samples

A sol-gel zirconia coating was developed for the preconcentration/separation of trace Cr, Cu, Cd and Pb by capillary microextraction, and the adsorbed analytes were on-line eluted for detection using inductively coupled plasma mass spectrometry (ICP-MS). By immobilizing sol-gel zirconia on the inner surface of a fused-silica capillary, the sol-gel zirconia coating was simply prepared. Its adsorption properties, stability and the factors affecting the adsorption behaviors of Cr, Cu, Cd and Pb were investigated in detail. In the pH range from 7.8 to 10, the zirconia-coated capillary (35 cm x 0.15 mm) is selective towards Cr, Cu, Cd and Pb, and the analyzed ions could be desorbed quantitatively with 0.2 mL of 0.5 mol/L HNO(3) at a rate of 0.2 mL/min. With a consumption of 1.25 mL sample solution, an enrichment factor of 6.25, and detection limits (3sigma) of 9.9 pg/mL Cr, 17.9 pg/mL Cu, 4.5 pg/mL Cd and 3.7 pg/mL Pb were obtained. The precisions for nine replicate measurements of 1 ng/mL Cr, Cu, Cd and Pb were 4.9% Cr, 2.2% Cu, 2.0% Cd and 3.2% Pb (RSD), respectively. The proposed procedure has been applied to the determination of Cr, Cu, Cd and Pb in human urine, which was subjected to microwave-assisted digestion prior to analysis, and the recoveries for these elements were 89.2-101.8%. In order to validate the developed procedure, a NIES No.10-a Rice Flour-Unpolished certified reference material and a BCR No. 184 Bovine Muscle certified reference material were analyzed, and the results are in good agreement with the certified values.

Determination of lead in biological samples by high-resolution continuum source graphite furnace atomic absorption spectrometry with direct solid sampling

Direct solid sampling is an attractive alternative for the determination of lead in biological samples, since it requires almost no sample preparation and provides higher sensitivity as no dilution is employed. In addition, the time required for the analysis and the risk of analyte loss or contamination during sample pre-treatment are reduced, the latter being the main problem associated with the usual digestion and dissolution procedures. In the present work, treating the determination of Pb in biological samples at 217.001 nm with solid sampling graphite furnace atomic absorption spectrometry (GF AAS), it will be shown that high-resolution continuum source AAS (HR-CS AAS) provides a variety of new possibilities for method development that have been unavailable previously. The use of ruthenium as a permanent modifier allowed a pyrolysis temperature of 900 °C to be applied, which was sufficient to eliminate the continuous background that preceded the analyte signal due to incomplete elimination of the matrix when lower pyrolysis temperatures were used. At atomization temperatures higher than 1500 °C, background absorption with pronounced fine structure followed the atomic signal. This was due to the electron excitation spectrum of PO, as was demonstrated by applying a least-squares background correction algorithm using the spectrum obtained by vaporization of (NH4)2HPO4 as a reference. Under optimum conditions, interference-free determination could be carried out by setting integration limits adjusted to integrate only the atomic signal; calibration against aqueous standards was performed and compared with calibration against a solid certified reference material (CRM). A total of seven biological CRM were analyzed (bovine muscle, pig kidney, lobster hepatopancreas, human hair, dogfish liver, oyster tissue and bovine blood), and the determined concentration of Pb was in agreement with the certified values using both calibration procedures, according to the t-test for a 95% confidence level. The detection limit (3s, n = 10) was 0.01 μg g−1, and the precision was typically better than 10%. The method is therefore adequate because of its simplicity, high sensitivity, good accuracy and wide applicability.

Determination of Pb in Biological Samples by Graphite Furnace Atomic Absorption Spectrophotometry. An Exercise in Common Interferences and Fundamental Practices in Trace Element Determination

This laboratory experiment demonstrates the use of graphite furnace atomic absorption spectrophotometry (GFAAS) for the determination of trace levels of Pb in bovine muscle or liver samples. The ma...

Simultaneous sample digestion and determination of Cd, Cu and Pb in biological samples using thermospray flame furnace atomic absorption spectrometry (TS-FF-AAS) with slurry sample introduction

In a Ni tube placed in an oxidizing air/acetylene AAS flame simultaneous digestion/oxidation of biological samples and powerful trace determinations were performed. A ceramic capillary was used for sample introduction. This capillary acted as a flame-heated thermospray nozzle (TS-FF-AAS). Slurry samples, prepared in 0.3 mol L−1 HNO3, were transported by a new 0.6 MPa (84 psi) flow injection system through the hot capillary into the flame tube furnace. A nitric acid vapour environment exists inside the tube at temperatures above 1000 °C oxidising the samples. The element traces could then be measured by AAS. For these investigations, 300 µL slurry samples (0.1 to 1.0% w/v) from various biological materials, such as pig kidney (CRM 186), bovine liver (SRM 1577), spinach (SRM 1570), orchard leaves (SRM 1571) citrus leaves (SRM 1572), tomato leaves (SRM 1573) and tomato puree were used. Reference values were additionally obtained by electrothermal atomic absorption spectrometry (ETAAS). The standard deviation (n = 10) was between 3 and 5% using the same slurry and about 10% when the whole process was repeated on subsequent days. The detection limits for Cd, Cu and Pb were found to be 0.5, 4.3 and 3.5 µg g−1, respectively. A t-test showed no differences between the found and certified values at a 95% confidence level. In all experiments the calibration could be performed with aqueous standard solutions.