Copper is an essential element for biological functions within humans and animals. There are several known diseases associated with Cu deficiency or overload, such as Menkes disease and Wilson disease, respectively. A common clinical method for determining extractable Cu levels in serum, which is thought to be potentially dangerous if in excess, is to subtract the value of tightly incorporated Cu in ceruloplasmin from total serum Cu. In this work, an automated sample preparation and liquid chromatography (LC) system was combined with inductively coupled plasma-mass spectrometry (ICP-MS) to determine bound Cu and extractable Cu in serum. This LC-ICP-MS method took 250 s for sample preparation and analysis, followed by a column recondition/system reset, thus, a 6-minute sample-to-sample time including sample preparation. The method was validated using serum collected from either control (Atp7b^+/-) or Wilson disease rats (Atp7b^-/-). The extractable Cu was found to be 4.0 ± 2.3 µM Cu in healthy control rats, but 2.1 ± 0.6 µM Cu in healthy Wilson rats, and 27 ± 16 µM Cu in diseased Wilson rats, respectively. In addition, the extractable Cu/bound Cu ratio was found to be 6.4 ± 3.5%, 38 ± 29%, and 34 ± 22%, respectively. These results suggest that the developed method could be of diagnostic value for Wilson disease, and possibly other copper related diseases.

The work described herein assesses the ability to characterize gold nanoparticles (Au NPs) of 50 and 100 nm, as well as 60 nm silver shelled gold core nanospheres (Au/Ag NPs), for their mass, respective size, and isotopic composition in an automated and unattended fashion. Here, an innovative autosampler was employed to mix and transport the blanks, standards, and samples into a high-efficiency single particle (SP) introduction system for subsequent analysis by inductively coupled plasma–time of flight–mass spectrometry (ICP-TOF-MS). Optimized NP transport efficiency into the ICP-TOF-MS was determined to be >80%. This combination, SP-ICP-TOF-MS, allowed for high-throughput sample analysis. Specifically, 50 total samples (including blanks/standards) were analyzed over 8 h, to provide an accurate characterization of the NPs. This methodology was implemented over the course of 5 days to assess its long-term reproducibility. Impressively, the in-run and day-to-day variation of sample transport is assessed to be 3.54 and 9.52% relative standard deviation (%RSD), respectively. The determination of Au NP size and concentration was of <5% relative difference from the certified values over these time periods. Isotopic characterization of the ¹⁰⁷Ag/¹⁰⁹Ag particles (n = 132,630) over the course of the measurements was determined to be 1.0788 ± 0.0030 with high accuracy (0.23% relative difference) when compared to the multi-collector–ICP-MS determination.

Measuring chromium species in drinking water has become of particular interest due to daily environmental contamination that is caused by industrial processes. Agencies such as the US Environmental Protection Agency and the European Union continue to investigate the maximum to which Cr(VI) contaminant levels should be set; thus laboratories must seek more efficient ways of performing routine analyses. In this work a single platform, automated speciation and total metals method is presented for chromium speciation in drinking water, waste water, industrial waters, and recipient waters, and for total metals in sludges, soils, organic waste, ashes, biological samples, or paint. Samples were measured using a prepFAST IC system for Cr(III) and Cr(VI) and the results were compared to the HPLC results. In addition, samples from the aqua regia total method were compared to those of the total metals method performed using the prepFAST IC. Sample comparisons resulted in linear regression plots with very good correlations, greater than 0.97 for total metals over a dynamic range of 0.010–100 000 μg L⁻¹ for 63 elements and greater than 0.98 for Cr(VI) speciation. The limits of detection for Cr(VI) and Cr(III) using the prepFAST IC and ICP-MS combination are 7 ng L⁻¹ and 12 ng L⁻¹, respectively. The new method resulted in an ∼43× improvement in detection limits as compared to the previous method employed in our laboratory. The accurate results for quality control samples of Cr(VI) were in good agreement with the historical values collected using the old method.