Determination of As, Hg and Pb in herbs using slurry sampling flow injection chemical vapor generation inductively coupled plasma mass spectrometry.
Analysis of herbs for As, Hg and Pb has been carried out using slurry sampling inductively coupled plasma mass spectrometry (ICP-MS) with flow injection vapor generation. Slurry containing 0.5% m/v herbal powder, 0.1% m/v citric acid and 2% v/v HCl was injected into the VG-ICP-MS system for the determination of As, Hg and Pb that obviate dissolution and mineralization. Standard addition and isotope dilution methods were used for quantifications in selected herbal powders. This method has been validated by the determination of As, Hg and Pb in NIST standard reference materials SRM 1547 Peach Leaves and SRM 1573a Tomato Leaves. The As, Hg and Pb analysis results of the reference materials agreed with the certified values. The precision obtained by the reported procedure was better than 7% for all determinations. The detection limit estimated from standard addition curve was 0.008, 0.003, and 0.007 ng mL(-1) for As, Hg and Pb, respectively.
Continuous plumbane generation in citric acid‐potassium ferricyanide medium for the determination of lead in environmental samples by atomic absorption spectrometry
Abstract A continuous plumbane generation‐atomic absorption spectrometric method is described for the determination of trace lead. Citric acid‐potassium ferricyanide was used as the reaction medium for sodium tetrahydroborate(III) reduction. Potassium ferricyanide enhanced the lead signal, while citric acid not only provided the acidity for the plumbane generation but also inhibited the interferences from foreign ions. Under optimized conditions, the sensitivity(0.0044 absorbance unit) and detection limit(3a) were 0.39 μg/L and 0.23 μg/L, respectively. Ten determinations of a 10 μg/L standard lead solution gave a RSD of 1.4%. Interferences from transition metals and hydride forming elements were studied. Copper severely interfered with the reduction. The proposed method has been successfully applied to determine lead contents in water samples and geological standard reference materials.
Method validation in pharmaceutical analysis
Method validation in pharmaceutical analysis , Method validation in pharmaceutical analysis , کتابخانه دیجیتال جندی شاپور اهواز