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Nitrile, Latex, Neoprene and Vinyl Gloves: A Primary Source of Contamination for Trace Element and Zn Isotopic Analyses in Geological and Biological Samples

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Abstract

Exogenic contamination is of primary concern for geochemical and biological clean laboratories working with sample sizes at the nanogram or even sub-picogram level. Here we determined sixty trace elements in fifteen different types of gloves from major suppliers worldwide to evaluate whether gloves could be potential sources of contamination for routine trace element and isotope measurements. We found that all gloves contain some trace elements that can be easily mobilised in significant amounts. In weak acid at room temperature, the tested gloves released up to 17 mg of Zn, more than 1 μg of Mg, Ti, Mn, Fe, Rb, Sr, Zr, Sn, Hf and Pb and between 100 and 1000 ng of Li, Sc, V, Cr, Ni, Cu, Ga, As, Se, Y, Ag, Ba, La, Ce, Nd, Tl and Th. Vinyl gloves released lower quantities of biologically and geologically important elements, with the exception of In and Sn. Isotopic analyses indicate that all gloves share roughly the same Zn isotopic composition (average δ66Zn = +0.10 ± 0.32‰ (2s)). A single contact between glove and labware releases an average of ~ 6 ng of Zn, and hence can significantly shift δ66Zn above the precision level when the amount of Zn determined is below 500 ng. This article is protected by copyright. All rights reserved.
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... Protective single-use gloves have previously been suspected to release a significant amount of Zn after contact with liquids or tissues. That may falsify results of Zn concentration analysis in veterinary and human medical samples as well as in samples from environmental analysis [18,19]. The general potential to contaminate fluids via nitrile, latex, neoprene and vinyl gloves used in laboratories was currently shown also by [19] describing a release of 11 μg up to 17 mg Zn after soaking gloves in 20 mL weak acid (0.4 mmol/L HNO 3 + 0.05 mmol/L HF) at room temperature for 40 h. ...
... That may falsify results of Zn concentration analysis in veterinary and human medical samples as well as in samples from environmental analysis [18,19]. The general potential to contaminate fluids via nitrile, latex, neoprene and vinyl gloves used in laboratories was currently shown also by [19] describing a release of 11 μg up to 17 mg Zn after soaking gloves in 20 mL weak acid (0.4 mmol/L HNO 3 + 0.05 mmol/L HF) at room temperature for 40 h. The leaching acid in this study corresponded to common dilution fluids used in ICP-MS analysis. ...
... μg Zn/L. The reaction time with contact of serum and glove used in our study was much lower compared to [19] being 10 min only underlining the high potential of gloves especially from type B and C to contaminate the serum. The range of contamination regarding the minimum and maximum Zn input within the 14 replications (Fig. 1) underlines, that even under standardized experimental conditions, the intensity of contamination varies. ...
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Preanalytical errors causing specimen contamination with zinc (Zn) are disastrous for routine medical diagnostics or scientific studies. The aim of the study presented here is to simulate contamination possibilities when using single-use gloves. The ability to release Zn into the specimen was tested using nitril (A), vinyl (B) and latex (C) gloves with 15 (14) replications. In our first approach, a 1 × 1 cm piece of the glove’s fingertip was incubated for 10 min with serum. Our second approach imitated a very short contact of serum to the glove’s material by letting serum run over the glove from a pipette for 3 cm distance into a tube. The effect of gloves’ contact to liver tissue was examined using glove C only: a block of liver tissue was touched once at one side producing an experimental fingerprint. Zn was analyzed in serum and liver wet weight (ww) using ICP-MS; the basal serum/liver Zn concentration was set as zero for calculation. The calculated addition of Zn is given as median (p25 - p75). The first approach led to distinct contamination with Zn (in µg/L) being evident from all three types of gloves, but depended markedly from the type of material: A: 176.5 (129.7–204); B: 975.1 (663.6–1164.3); C: 2112 (1685–2516). Imitating a very short contact of serum to the glove’s surface resulted in an additional Zn concentration of 105.7 (70.4–168.8), 56.2 (-13.5–121.4) and 955.7 (746–1159) µg/L using gloves A, B and C, respectively. A single fingerprint on liver tissue using glove C resulted an addition of 3995 (861–6435) µg Zn/kg liver ww. The data underline that the dimension of pre-analytical contamination of blood and tissue samples for Zn analysis via single-use gloves is relevant for routine diagnostics and scientific studies. Critical steps and possibilities to minimize these effects should be considered seriously for specimen handling in routine laboratory diagnostics as well as in scientific studies to avoid preanalytical errors and, finally, misinterpretation of the data.
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... In addition, the PTEs are used as additives in plastics; hence, there is a risk in the releasing of those to the environment. For instance, Garçon et al. [45] observed PTEs leached from 15 different types of disposable protective gloves irrespective of the colors and materials of them. Soaking of gloves for 40 h in 0.4 M HNO 3 + 0.05 M HF released 60 different types of elements and most of them were belonging to PTEs (i.e., Fe, Hf, Mg, Mn, Pb, Rb, Sr, Sn, Ti, Zr, Ag, As, Ba, Ce, Cr, Cu, Ga, La, Li, Nd, Ni, Sc, Se, Th, Tl, V, and Y). ...
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