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The identification of uncertainties caused by sample inhomogeneity, as distinct from those caused by sample preparation and measurement, is a challenging task. Use of chemometric methods to separate and estimate these contributions to the combined standard uncertainty of a measurement (u c ) of an analytical result requires complex experiments. The difficulty of platinum group element measurement makes this task even more complex. But unless it can be demonstrated that sample inhomogeneity is the major contributor to the high variability of an analytical result one should be careful not to mistakenly attribute this to a nugget effect. In this contribution we are able to demonstrate in two special cases that irreproducible results (up to 90% RSD) for analysis of Os and Re in the pg g–1 to ng g–1 range are truly caused by a nugget effect and not by inadequacies of the analytical method. [ABSTRACT FROM AUTHOR]

Square-wave voltammetry (SWV) has been used to study the transfer of zinc(II) ion under static conditions, assisted by 5,6-diphenyl-3-(2-pyridyl)-1,2,4-triazine (DPT), through gel-supported microinterfaces. Microhole arrays created by laser photoablation of thin polyester films were used to support an organic gel phase prepared by addition of 1,3 : 2,4-dibenzylidenesorbitol (DBS) to a solution of o-nitrophenyloctyl ether (o-NPOE) with the appropriate supporting electrolyte. The results show that SWV can be used with the gel-supported microinterfaces if a gelified aqueous reference is used for the organic phase. Under such conditions a preliminary estimate of the detection limit for the determination of Zn2+ is 5 × 10–8 mol L–1. [ABSTRACT FROM AUTHOR]

This report focuses on the status, requirements, and potentials of CE-ICP-MS. The ultimate goal of a viable CE-ICP-MS system is to obtain quantitative elemental speciation information and isotopic ratio data for practical biological and environmental metal containing compounds. To make use of the CE separation features, the CE analyte must be introduced efficiently into the ICP. For practical samples, pre- and post-separation enrichment techniques probably are required. The features of electrospray ion sources that can be incorporated in CE-ICP-MS and the potential for microfabricated CE are discussed. [ABSTRACT FROM AUTHOR]

The performance of two liquid chromatography-mass spectrometry (LC/MS) interfacing techniques, thermospray (TSP) and atmospheric pressure chemical ionization (APCI), for the analysis of benzo[ a]pyrene (BaP) metabolites (hydroxy, epoxy and quinone derivatives) was compared. Interface and detection parameters such as source temperature, eluent composition or flow rate were optimized using negative ion mode. In TSP, the main ions are mostly [M]-, [M−H2O]- or [M+CH3COO]-, whereas APCI gives mainly the [M]- and [M−H]- ions. Quantification was carried out by flow injection. Calibration graphs were linear in the range of 10 ng to 1000 ng in TSP and 0.1 ng to 10 ng in APCI. Detection limits were in the range of 1 ng to 20 ng in TSP and 0.002 ng to 0.2 ng in APCI. The presence of BaP-1,6-dione, BaP-3,6-dione, and BaP-6,12-dione was confirmed in environmental samples of air particulate matter. [ABSTRACT FROM AUTHOR]