scholarly journals Determination Of Silver In Geological Samples Using Aerosol Dilution ICP-MS After Water-Bath Extraction With Inverse Aqua Regia

2021 ◽  
Vol 42 (6) ◽  
Author(s):  
Yan Wu
Keyword(s):  
Inductively Coupled Plasma ◽  
Signal To Noise Ratio ◽  
Accurate Determination ◽  
Standard Reference Materials ◽  
Geological Samples ◽  
Aqua Regia ◽  
Inductively Coupled ◽  
Traditional Mode ◽  
Plasma Mass Spectrometry

A valid method for trace silver (Ag) detection in geological samples was developed in this study using aerosol dilution inductively coupled plasma-mass spectrometry after extraction with inverse aqua regia. This was proposed primarily to reduce the interference from Nb and Zr during mass spectrometric measurements. Almost 93% of Nb and Zr was removed after the extraction. By mixing an appropriate amount of Ar with the sample aerosol using an aerosol dilution system prior to plasma, the residual Nb oxides and Zr oxides or hydroxides could be successfully removed. The relative yields of the interfering oxides and hydroxides were as low as 0.087% (NbO/Nb) and 0.013% (ZrOH/Zr), which were 3–5 times lower than those in the traditional mode without the addition of Ar. Moreover, the signal-to-noise ratio of Ag was five times higher than that in the traditional mode. The proposed method was applied to the determination of Ag in 68 standard reference materials (SRMs) of soil, sediment, and rock. The results for 47 of these geological SRMs were in good agreement with the reference values. The Ag levels in three SRMs (GSP-2 Granodiorite, STM-2, and SGR-1b) are being reported for the first time herein. For these SRMs, 10 separate aliquots of the sample were digested and analyzed over a period of three months, and analysis revealed that the determined values were reasonable. Thus, the proposed method shows significant potential for the accurate determination of trace Ag in various geological samples.

Application of Inductively Coupled Plasma/Mass Spectrometry for the Measurement of Chromium, Selenium, and Molybdenum in Infant Formula and Adult Nutritional Products: First Action 2011.19

2012 ◽  
Vol 95 (3) ◽  
pp. 588-598 ◽  
Author(s):  
Lawrence H Pacquette ◽  
Andre Szabo ◽  
Joseph J Thompson ◽  
Steve Baugh
Keyword(s):  
Infant Formula ◽  
Inductively Coupled Plasma ◽  
Internal Standard ◽  
Reference Method ◽  
Standard Reference Materials ◽  
Internal Standards ◽  
Inductively Coupled ◽  
Technology Standard ◽  
Plasma Mass Spectrometry

Abstract An inductively coupled plasma/MS method was developed for the simultaneous determination of Cr, Se, and Mo in infant formula and other nutritional products. All samples were digested using a closed vessel microwave oven system, together with Ni and Te internal standards. The practical quantitation limits for Cr, Se, and Mo were 0.4, 0.2, and 0.4 ng/mL, respectively; dilution factors were 250 for powders and 50 for liquids. The Cr, Se, and Mo concentrations in 10 nutritional products were within specification limits; within-day and day-to-day (6 independent days) precision values were <5% RSD. For two control samples, the observed precision was ≤2% RSD over 10 independent days. Cr, Se, and Mo results were within the certified limits in three National Institute of Standards and Technology standard reference materials. The average sample spike recoveries for 10 nutritional products ranged from 93 to 107%. Robustness studies showed a minimal effect from concomitant easily ionized element concentrations. However, the choice of internal standard and matrix-matching carbon content were critical to obtaining accurate Se results. All indications are that this method would be a suitable candidate as a global reference method for the determination of these trace elements in infant formula, adult nutritionals, and other nutritional products.

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