Useful and Fast Method for Blood Lead and Cadmium Determination Using ICP-MS and GF-AAS; Validation Parameters

Boron and Nitrogen Co-Doped Porous Graphene Nanostructures for the Electrochemical Detection of Poisonous Heavy Metal Ions

Heavy metal poisoning has a life-threatening impact on the human body to aquatic ecosystems. This necessitates designing a convenient green methodology for the fabrication of an electrochemical sensor that can detect heavy metal ions efficiently. In this study, boron (B) and nitrogen (N) co-doped laser-induced porous graphene (LIGBN) nanostructured electrodes were fabricated using a direct laser writing technique. The fabricated electrodes were utilised for the individual and simultaneous electrochemical detection of lead (Pb2+) and cadmium (Cd2+) ions using a square wave voltammetry technique (SWV). The synergistic effect of B and N co-doping results in an improved sensing performance of the electrode with better sensitivity of 0.725 µA/µM for Pb2+ and 0.661 µA/µM for Cd2+ ions, respectively. Moreover, the sensing electrode shows a low limit of detection of 0.21 µM and 0.25 µM for Pb2+ and Cd2+ ions, with wide linear ranges from 8.0 to 80 µM for Pb2+ and Cd2+ ions and high linearity of R2 = 0.99 in case of simultaneous detection. This rapid and facile method of fabricating heteroatom-doped porous graphene opens a new avenue in electrochemical sensing studies to detect various hazardous metal ions.

Screen-Printed Sensors Modified with Nafion and Mesoporous Carbon for Electrochemical Detection of Lead in Blood

Lead (Pb) has long been acknowledged as a systemic toxicant, with pronounced health impacts observed even at low exposure levels, particularly in children. Adverse effects include diminished cognitive function, altered behavior, and developmental delays. Consequently, it is imperative to conduct regular monitoring of Blood Lead Levels (BLLs). In this work, we report on an electrochemical sensor based on screen-printed carbon electrode (SPCE) coated with Nafion and mesoporous carbon (MC). The sensor system uses simple sample preparation (acidification and dilution of whole blood), minimal sample volume (a few blood drops, 200 μl), and swift time-to-results (1 h). A limit of quantitation (LOQ) of 0.3 μg dL-1 Pb was achieved in whole blood. To demonstrate the practical utility of our sensor system, we evaluated its performance in the analysis of blood samples collected from children (n = 25). Comparative analysis with the laboratory-based gold standard method of inductively coupled plasma mass spectrometry (ICP-MS) demonstrated approximately 77% accuracy and 94% precision. We anticipate that our approach will serve as a valuable tool for more frequent BLL monitoring, particularly in communities where access to laboratory testing is impractical or expensive.

A comparative study of different methods for the determination of cadmium in various tissues of ramie (Boehmeria nivea L.)

Remediation of cadmium (Cd) pollution is one of the priorities of global environmental governance and accurate detection of Cd content is a key link in remediation of Cd pollution. This study aimed to compare three methods (inductively coupled plasma optical emission spectrometry (ICP-OES), inductively coupled plasma mass spectrometry (ICP-MS), and graphite furnace-atomic absorption spectrometry (GF-AAS)) for the determination of Cd with different tissues of various ramie varieties, and distinguish the advantage and disadvantage of each method. In total, 162 samples of ramie (Boehmeria nivea L.), which is an ideal plant for heavy metal remediation, were detected and the results showed that the three methods were all suitable for the de-termination of Cd content in ramie. ICP-OES and ICP-MS were simpler, faster, and more sensitive than GF-AAS. ICP-MS could be recommended for the determination of samples with various concentrations of Cd. ICP-OES could be used for measurement of samples with > 100 mg/kg Cd content, while GF-AAS was suitable for the detection of samples with very high (> 550 mg/kg) or very low (< 10 mg/kg) Cd content. Overall, considering the accuracy, stability, and the cost of measurement, ICP-MS was the most suitable method for determination of Cd content. This study provides significant reference information for the research in the field of Cd pollution remediation.

Improving Equitability and Inclusion for Testing and Detection of Lead Poisoning in US Children

Policy Points Child lead poisoning is associated with socioeconomic inequity and perpetuates health inequality. Methods for testing and detection of child lead poisoning are ill suited to the current demographics and characteristics of the problem. A three-pronged revision of current testing approaches is suggested. Employing the suggested revisions can immediately increase our national capacity for equitable, inclusive testing and detection. ABSTRACT: Child lead poisoning, the longest-standing child public health epidemic in US history, is associated with socioeconomic inequity and perpetuates health inequality. Removing lead from children's environments ("primary prevention") is and must remain the definitive solution for ending child lead poisoning. Until that goal can be realized, protecting children's health necessarily depends on the adequacy of our methods for testing and detection. Current methods for testing and detection, however, are no longer suited to the demographics and magnitude of the problem. We discuss the potential deployment and feasibility of a three-pronged revision of current practices including: 1) acceptance of capillary samples for final determination of lead poisoning, with electronic documentation of "clean" collection methods submitted by workers who complete simple Centers for Disease Control and Prevention-endorsed online training and certification for capillary sample collection; 2) new guidance specifying the analysis of capillary samples by inductively coupled plasma mass spectrometry or graphite furnace atomic absorption spectrometry with documented limit of detection ≤0.2 μg/dL; and 3) adaptive "census tract-specific" universal testing and monitoring guidance for children from birth to 10 years of age. These testing modifications can bring child blood lead level (BLL) testing into homes and communities, immediately increasing our national capacity for inclusive and equitable detection and monitoring of dangerous lower-range BLLs in US children.

Development and validation of Graphite Furnace Atomic Absorption Spectrometry method and its application for clinical evaluation of blood lead levels among occupationally exposed lead smelting plant workers

The growing interest in estimating the blood lead levels, for early detection of lead exposure, warranted a need for a validated analytical method for trace levels estimation of lead. The present study aimed to develop an analytical method for detecting trace amounts to elevated levels of lead in human blood using the Graphite Furnace Atomic Absorption Spectrometry technique and its application in evaluating blood lead levels among occupationally exposed individuals. The method validation was performed with standard test parameters including linearity, recovery, precision, method detection limit, and limit of quantification. The validation results for each performance parameter were in agreement with acceptable criteria as per standard guidelines. The correlation was observed as optimum linear (R² = 0.998) between absorbance and lead concentration range from 0 to 10 µg/dL. The recoveries for spiked samples ranged between 95 and 105%. The calculated value for the method detection limit was 0.16 µg/dL and the limit of quantification was 0.51 µg/dL. The precision for all spiked concentrations was below 10% of the relative standard deviation. Evaluation of lead exposure among occupationally exposed individuals revealed the study population had found average blood lead level (42.80 ± 12.47 µg/dL), which was above the upper acceptable limit suggested by Occupational Safety and Health Administration, USA. The majority of system-specific symptoms were observed among study groups having mean blood lead levels above 40 µg/dL. However, sociodemographic status and employment factors were found possible determinants of the prevalence of high blood lead levels.

A Novel Aptamer-Imprinted Polymer-Based Electrochemical Biosensor for the Detection of Lead in Aquatic Products

Lead contamination in aquatic products is one of the main hazard factors. The aptasensor is a promising detection method for lead ion (Pb(II)) because of its selectivity, but it is easily affected by pH. The combination of ion-imprinted polymers(IIP) with aptamers may improve their stability in different pH conditions. This paper developed a novel electrochemical biosensor for Pb(II) detection by using aptamer-imprinted polymer as a recognition element. The glassy carbon electrode was modified with gold nanoparticles and aptamers. After the aptamer was induced by Pb(II) to form a G-quadruplex conformation, a chitosan-graphene oxide was electrodeposited and cross-linked with glutaraldehyde to form an imprint layer, improving the stability of the biosensor. Under the optimal experimental conditions, the current signal change (∆I) showed a linear correlation of the content of Pb(II) in the range of 0.1-2.0 μg/mL with a detection limit of 0.0796 μg/mL (S/N = 3). The biosensor also exhibited high selectivity for the determination of Pb(II) in the presence of other interfering metal ion. At the same time, the stability of the imprinted layer made the sensor applicable to the detection environment with a pH of 6.4-8.0. Moreover, the sensor was successfully applied to the detection of Pb(II) in mantis shrimp.

Prenatal exposure to neurotoxic metals and micronutrients and neurodevelopmental outcomes in early school age children from Poland

Exposure to environmental factors, such as neurotoxic metals and micronutrients, during critical periods of development can contribute to long-term consequences in offspring's health, including neurodevelopmental outcomes. The aim of this study was to evaluate the association between simultaneous prenatal exposure to metals [lead (Pb), cadmium (Cd), mercury (Hg)] and micronutrients [selenium (Se), zinc (Zn), copper (Cu)] and neurodevelopmental outcomes in school-age children from the Polish Mother and Child Cohort (REPRO_PL). Metals and micronutrients concentrations were measured in cord blood (Pb, Cd, Se, Zn, Cu) and in maternal hair (Hg) collected during the 3rd trimester of pregnancy. Behavioral and emotional problems, as well as children's cognitive and psychomotor development, were assessed in 436 school-age children using the Strengths and Difficulties Questionnaire (SDQ, filled in by the mothers) and the Polish adaptation of the Intelligence and Development Scales (IDS, administered by trained psychologists). Multivariate regression models were applied after imputation of missing values, using two approaches: (i) a joint analysis taking into account all metals and micronutrients simultaneously, and (ii) an ExWAS study (single-exposure model). In the SDQ, Hyperactivity/Inattention problems and Total difficulties were associated with higher Hg concentrations in maternal hair (0.18, 95% CI: 0.05; 0.3; and 0.14, 95% CI: 0.01; 0.3, respectively), whereas Emotional symptoms were inversely associated with Se and Zn levels in cord blood (-0.13, 95% CI: -0.3; 0.004; and -0.10, 95% CI: -0.2; 0.02, respectively). In the IDS, cord blood Pb levels were found to be negatively associated with Fluid and Crystallized IQ (-0.12, 95% CI: -0.3; 0.02; and -0.14, 95% CI: -0.3; 0.007, respectively) as well as Mathematical skills (-0.15, 95% CI: -0.3; 0.01). The current research has been able to simultaneously assess the exposure to various interacting chemicals during the prenatal period. We demonstrate that prenatal co-exposures to Pb, Hg, Zn and Se have long-term influences on the neuropsychological outcome of school-age children.

The relationship between oral cancer and cadmium: a review

Cadmium (Cd) has been classified as a type I carcinogen. Since it is ingested orally through food and tobacco use, Cd is likely to be closely related to oral cancers. The relationship between cadmium and oral cancer was investigated using papers on Pubmed and Web of Science. Thus a total of 11 studies from these databases were included in the review. Cd concentrations were significantly higher in both the blood and hair of oral cancer patients than in controls. Additionally, it has been reported that Cd increases the activity of reactive oxygen species. Tobacco plants contain varying levels of Cd. The presence of high Cd concentrations in patients who use tobacco products and develop oral cancer is strong evidence that Cd is directly related to oral cancer. While planning a study to determine the Cd concentrations in biological samples, it is advisable to examine the methodologies of previous studies and to avoid technical deficiencies. New cell line studies are required to explain the relationship between Cd and autophagy-apoptosis.

Determination of trace cadmium in saliva samples using spray assisted droplet formation-liquid phase microextraction prior to the measurement by slotted quartz tube-flame atomic absorption spectrophotometry

BACKGROUND

An effective, green and rapid analytical strategy namely the simultaneous spray assisted droplet formation-liquid phase microextraction (S-SADF-LPME) method was developed for the determination of trace quantity of cadmium in saliva samples by using the slotted quartz tube-flame atomic absorption spectrophotometry (SQT-FAAS). By the developed method, external dispersive solvent usage for droplet formation was reduced to obtain a more environmental-friendly method.

METHODS

Method consists of a simultaneous complexing and extraction step, which was based on spraying an extraction solvent containing a solid ligand into the aqueous sample solution, forming fine droplets without the use of dispersive solvent. The procedure was implemented using a customized, cost effective and portable spray apparatus to minimize the consumption of reagent, analysis time and operation steps. Thus, this methodology ensures better repeatability and accuracy while minimizing the relative errors caused by the experimental steps. Parameters including the buffer amount, extractant/ligand concentration, extraction solvent type, extraction/ligand solution volume, spraying number and vortex period were systemically optimized to lower the detection limit.

RESULTS

Under the optimal extraction conditions, 96.9-folds enhancement in the detection power of the traditional FAAS was achieved. The limit of detection and limit of quantification values of presented method were calculated to be 0.65 and 2.17 ng mL^-1, respectively. Accuracy and applicability of the optimized method was investigated by collecting saliva samples from smokers. Satisfactory percent recovery values wereachieved for cadmium with a low standard deviation in the acceptable range of 84.9-109.6 %.

CONCLUSION

The developed dispersive solvent-free S-SADF-LPME technique presents a fast, simple, cost-effective and eco-friendly microextraction method based on the use of an easily accessible and functional spray apparatus.

Interlaboratory comparison investigations (ICI) and external quality assurance schemes (EQUAS) for cadmium in urine and blood: Results from the HBM4EU project

Human biomonitoring (HBM) of cadmium is essential to assess and prevent toxic exposure. Generally, low cadmium levels in urine and blood of the general population place particularly high demands on quality assurance and control measures (QA/QC) for cadmium determination. One of the aims of the HBM4EU project is to harmonize and advance HBM in Europe. Cadmium is one of the chemicals selected as a priority substance for HBM implementation in the 30 European countries under HBM4EU. For this purpose, analytical comparability and accuracy of the analytical laboratories of participating countries was investigated in a QA/QC programme comprising interlaboratory comparison investigations (ICI) and external quality assurance schemes (EQUAS). This paper presents the evaluation process and discusses the results of four ICI/EQUAS rounds for the determination of cadmium in urine and blood. The majority of the 43 participating laboratories achieved satisfactory results, although low limits of quantification were required to quantify Cd concentrations at general population exposure levels. The relative standard deviation of the participants' results obtained from all ICI and EQUAS runs ranged from 8 to 36% for cadmium in urine and 8-28% for cadmium in blood. Applying inductively-coupled plasma mass spectrometry (ICP-MS), using an internal standard, and eliminating molybdenum oxide interferences was favourable for the accurate determination of cadmium in urine and blood. Furthermore, the analysis of cadmium in urine was found to have a critical point at approximately 0.05 μg/l, below which variability increased and laboratory proficiency decreased. This QA/QC programme succeeded in establishing a network of laboratories with high analytical comparability and accuracy for the analysis of cadmium across 20 European countries.

The assessment of the usability of selected instrumental techniques for the elemental analysis of biomedical samples

The fundamental role of major, minor and trace elements in different physiological and pathological processes occurring in living organism makes that elemental analysis of biomedical samples becomes more and more popular issue. The most often used tools for analysis of the elemental composition of biological samples include Flame and Graphite Furnace Atomic Absorption Spectroscopy (F-AAS and GF-AAS), Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES) and Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Each of these techniques has many advantages and limitations that should be considered in the first stage of planning the measurement procedure. Their reliability can be checked in the validation process and the precision, trueness and detection limits of elements belong to the most frequently determined validation parameters. The main purpose of this paper was the discussion of selected instrumental techniques (F-AAS, GF-AAS, ICP-OES and ICP-MS) in term of the achieved validation parameters and the usefulness in the analysis of biological samples. The focus in the detailed literature studies was also put on the methods of preparation of the biomedical samples. What is more based on the own data the usefulness of the total reflection X-ray fluorescence spectroscopy for the elemental analysis of animal tissues was examined. The detection limits of elements, precision and trueness for the technique were determined and compared with the literature data concerning other of the discussed techniques of elemental analysis. Reassuming, the following paper is to serve as a guide and comprehensive source of information concerning the validation parameters achievable in different instrumental techniques used for the elemental analysis of biomedical samples.

The Immunotoxicity of Chronic Exposure to High Levels of Lead: An Ex Vivo Investigation

Lead (Pb) is a toxic metal known for its wide-ranging adverse health effects. However, a compound of Pb is still used in the caulking process to repair wooden fishing boats. The present study aimed to measure Pb exposure and its immunologic effects in boatyard workers in Nakhon Si Thammarat province, Thailand, in comparison with an age-matched control group of farmers. The age, body mass index, and smoking history in workers (n = 14) and controls (n = 16) did not differ. The median blood Pb concentration was 8.7-fold higher in workers than controls (37.1 versus 4.3 µg/dL, p < 0.001). Workers had 8.4% lower phagocytic active cells than controls (89.9% versus 98.1%, p = 0.019). In response to a mitogen stimulation, the peripheral blood mononuclear cells (PBMCs) from workers produced 2-fold higher ratios of interleukin-4 (IL-4) to interferon-γ than the PBMCs from controls (p = 0.026). Furthermore, Pb-exposed workers had 33.9% lower cytotoxic T (Tc) cells than controls (24.3% versus 36.8%, p = 0.004). In stark contrast, the percentage of regulatory T (Treg) cells in workers was 2.7-fold higher than controls (6.1% versus 2.3%, p < 0.001). In all subjects, blood Pb showed positive correlations with the percentages of Treg cells (r = 0.843, p < 0.001) and IL-4 (r = 0.473, p = 0.041) while showing an inverse correlation with the percentages of Tc cells (r = −0.563, p = 0.015). These findings indicate that chronic high Pb exposure may cause a shift towards humoral immune response, together with a suppression of cellular immunity, thereby suggesting an elevation in cancer risk in Pb-exposed workers.

Microwave-assisted synthesis of BSA-stabilised gold nanoclusters for the sensitive and selective detection of lead(ii) and melamine in aqueous solution

MW-assisted synthesis of fluorescent BSA-AuNCs for the turn-off sensing of Pb(ii) and turn-on sensing of melamine.