Papers by Keyword: ICP-MS

Abstract: The new laser ablation technique has been developed for analysis of metallic impurities in SiC and GaN wafers. Particles generated by a femto-second laser ablation were aspirated by an ejector and introduced to an Inductively Coupled Plasma Mass Spectrometry (ICP-MS) via a Gas Exchange Device (GED) and analyzed. A Metal Standard Aerosol Generation (MSAG) was used for quantitation of metallic impurities in SiC and GaN wafers.

Abstract: A balance between forest growth and deforestation must be maintained to ensure sustainable wood production. Faster forest growth increases the economic benefit and to achieve faster forest growth it should be provided with nutrients from which one of the most important is nitrogen. In this study, nitrogen isotope ratio and elemental concentrations were determined in samples of pine needles, which were collected in plots where nitrogen-containing soil improver (arginine phosphate) was used, as well as in plots without additional nitrogen input. The aim of the study was to evaluate the effect of arginine-containing soil improvers on the nitrogen and other element content in pine needles harvested from selected plots. The obtained results indicate that arginine phosphate fertilizer was taken up by pine seedlings - an increase in nitrogen (0.05% for control samples and 0.7% for samples applied with a soil improver) and a decrease in nitrogen isotope ratio were observed.

Abstract: Tea infusion is one of the most widely popular beverages. With several medicinal activities, mulberry leaf is listed as a raw material for tea infusion by the Thai Ministry of Public Health. However, long-term consumption may lead to health risk from toxic trace elements accumulated in herbal raw materials. In this research, the potentially toxic metal (including As, Cd, Pb, Ni and Ba) contents were determined in six mulberry reference leaves and nineteen commercial tea infusion products from local harvester (LHG) and non-harvester (non-LHG) groups using ICP-MS. Each sample was analyzed in triplicate. Health risks of toxic metal consumption was evaluated through content mean value, t-test and Pearson correlation at the significance level of 0.05. The relevant aspects of principal component analysis were also discussed. No observed contents of heavy metals in all sample exceeded the limitation of Thai FDA and WHO. Yet, it was notified that quantity of As, Cd, Ni and Ba in commercial products was higher than that of references while there was no difference in Pb content between two groups. Further investigation found that Cd, Ni and Ba contents in samples from LHG were lower than those from non-LHG significantly. On the contrary, higher Pb content was found in sample from LHG than that from non-LHG group. The amount of As was not different in both groups. As the result, awareness of environmental controls in cultivation area and proper production is crucial to reduce health risk of exposure to heavy metals.

Abstract: Gas Exchange Device (GED) was integrated with Inductively Coupled Plasma Mass Spectrometry(ICP-MS) for analysis of metallic particles in NH3 and HCl gases used in semiconductormanufacturing. A single pg/kg (ppq) level of metallic impurities in these gases could be determinedwithout any sample preparation.

Abstract: This study aims to measure the concentration of heavy metals of concern Lead (Pb), Copper (Cu), Chromium (Cr), Cadmium (Cd) and Nickel (Ni) at three university campus buildings which was situated adjacent to an industrial district. Heavy metals particulates were sampled from the PM₁₀ sampling device (Met One Instrument) in 24 hours sampling between lecture and holiday periods. Determination of heavy metals concentrations were conducted using Inductively Coupled Plasma – Mass Spectrometry (ICP-MS) after the filter papers were digested with mixture of nitric acid (HNO₃) and sulphuric acid (H₂SO₄). These heavy metal concentrations were compared to the Standard Concentration on Air such as World Health Organization Health (WHO), Ambient Air Quality Criteria Act 1994 (AAQC), National Environment Protection Council (NEPS) and also Texas Commission on Environmental Quality (TCEQ). The comparison with Standard Concentration of Air shows that Cd and Cu have low concentrations 0.0033±0.0018 μg/m³ and 0.0894±0.0614 μg/m³ while Cr and Ni have high concentrations of 0.1882±0.0535 μg/m³ and 0.1278±0.0323 μg/m³ respectively. The Pb gives irregular result and high standard deviation of 2.0410±3.4999 μg/m³. This finding produces significant contribution to some knowledge of the level of heavy metals in the study area. It identifies research needs and suggests potential approaches to addressing outstanding problems.

Abstract: Moringa oleifera Lam. leaf capsules collected from markets in Nakhon Pathom, Thailand were determined for 11 heavy metals (Al, As, Cd, Cr, Cu, Fe, Hg, Mn, Ni, Pb, and Zn) by inductively coupled plasma-mass spectrometry (ICP-MS) using acid digestion for sample preparation. The concentrations of Al, As, Cr, Cu and Hg in all samples of M. oleifera capsules were found within permissible limits and normal ranges. In contrast, Fe, and Zn concentrations in all samples were higher than permissible limits. Furthermore, the concentrations of Cd, Mn, Ni, and Pb in some samples were higher than permissible limits and normal ranges. The presence of elevated levels of Cd, Fe, Mn, Ni, Pb, and Zn in M. oleifera capsules is a serious matter of concern. Therefore, it is important that doctors and consumers are aware of this matter especially during the routine taking of M. oleifera capsules.

Abstract: Seven groups of herbal drinks including gum karaya, Indian gooseberry, Noni Indian mulberry, cat's whiskers, prickly-leaved elephant's foot, black galingale, and Ling zhi mushroom contain a variety of bioactive compounds such as polysaccharides, terpenes, saponins, and flavonoids. The extracts of these plants have several biological activities such as analgesic, anti-inflammatory, antibacterial, antioxidant and chemoprotective activities that can promote health. The popular uses of herbal drinks in Thailand raise the question about safety of their products, especially for heavy metal contamination. The concentrations of heavy metals such as As, Pb, Cu, Zn, Fe, and Cd in twenty one samples from seven groups of herbal drinks were determined by ICP-MS. None of herbal drinks passed the permissible limits under the Notification of Ministry of Public Health (No. 214) B.E. 2543 (2000) Re: Beverages in Sealed Container by the virtue of the Food Act B.E. 2522 (1979), Thailand. Moreover, the concentrations of Pb and Zn in all analyzed samples were higher than the permissible limits. The concentrations of Fe in almost all analyzed samples as well as the concentrations of As, Cd, and Cu in some analyzed samples were higher than the permissible limits. The levels of heavy metals found in this study raise concerns, not only for the safety of Thai consumers, but also the quality of herbal drinks available in Thailand.

Abstract: Objective: A method based on high pressure digestion andinductively coupled plasma mass spectrometry (ICP-MS) detection was establishedfor determination of arsenic, mercury, lead, cadmium, chromium and thallium inbiological tissues. Method: The samplesof hair, nails, viscera, blood, urine were digested with HNO₃ and H₂O₂in high pressure digestion tank ; Indium was used as internal standard element,The certified GBW07601a (CRM Human Hair) was adopted as the quality control forthe whole processes. Results: Theexcellent sensitivity and reliability were demonstrated by the method ofrecovery 82% ~ 110%, RSD (n = 5) less than 5% and the linear range of 0.020ng/mL to 100 ng/mL (r > 0.99). The prototype measurements are within thescope of the standard value. Standard addition recovery of the six elements is therange of 92% ~ 105%. Conclusion: Arapid, easy and accurate quantitative ICP-MS method was established fordetermination of toxic elements in the human body, which enrich the existing meansof forensic technology. At the same time, this work provide the most practicaland reliable core data for poisons metabolism and pathological study.

Abstract: The dynamic adsorption of atmospheric trace Kr and Xe, which discharged from the dynamic adsorption experimental equipment at room temperature, on selected adsorbents VACF and GCAC were studied. The stable isotope ⁸⁴Kr and ¹²⁹Xe were designated as tracing indicator and determined by ICP-MS. The results suggest that: (1) under the experimental conditions, which included that the column length was 1m, the flow was 2m³/h, and the maximum uniform loading density of VACF column and GCAC column was respectively 0.0165 g/cm³ and 0.459 g/cm³, the DAC which indicated the adsorption capacity of Kr and Xe adsorbed on VACF at room temperature was about 3.08×10⁴cm³/g, the DAC which indicated the adsorption capacity of Kr and Xe adsorbed on GCAC at room temperature was about 5.55×10³cm³/g; (2) the air flow capacity couldn’t be promoted by simply increasing the column length of VACF or GCAC. For VACF adsorbent, although its DAC was superior to the GCAC’s, but when the length of VACF column was increased to 2m, the air flow resistance was ascended obviously, and the air flow capacity was descended substantially. However, because the cost-effectiveness of GCAC adsorbent was higher, the flow resistance of GCAC column was smaller and the controlling range of air flow was larger than VACF, all of these results show that the comprehensive performance of GCAC is better than VACF at present.

Abstract: The concentrations of essential trace elements such as Mn, Cu, Zn, Fe, Li and Se were determined in pomegranate juice at distinct maturity stages by ICP-MS following microwave-assisted acid digestion. The digestion efficiency was evaluated on the basis of the determination of residual carbon content and residual acidity. 4 mL of 16 mol/L HNO₃ + 2 mL of 30% m/m H₂O₂ solutions were used for the efficient digestion of 3.0 mL pomegranate juice, with a considerable reduction in the residual acidity when compared with a procedure that employed different Digestion procedures. The good agreement between the observed and certified concentrations of the National Tea Standard (China, GBW10016) and the Apple Standard (China, GBW10019) indicate that the developed analytical method was well suited to determine the trace elements contents in similar matrices.