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.

scholarly journals Simultaneous Determination of Chromium, Selenium, and Molybdenum in Nutritional Products by Inductively Coupled Plasma/Mass Spectrometry: Single-Laboratory Validation

2011 ◽  
Vol 94 (4) ◽  
pp. 1240-1252 ◽  
Author(s):  
Lawrence H Pacquette ◽  
Andre Szabo ◽  
Joseph T Thompson
Keyword(s):  
Simultaneous Determination ◽  
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 formulas 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 specifcation limits, and 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. In three National Institute of Standards and Technology standard reference materials, Cr, Se, and Mo results were within the certifed limits. 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 nutritional products.

Determination of Ultratrace Levels of Lead in Infant Formula by Isotope Dilution Inductively Coupled Plasma Mass Spectrometry

1993 ◽  
Vol 76 (6) ◽  
pp. 1378-1384 ◽  
Author(s):  
Joseph J Thompson
Keyword(s):  
Mass Spectrometry ◽  
Infant Formula ◽  
Reference Materials ◽  
Isotope Dilution ◽  
Inductively Coupled Plasma ◽  
Standard Reference Materials ◽  
Inductively Coupled ◽  
Relative Standard ◽  
Plasma Mass Spectrometry

Abstract A simple method was developed for the accurate and precise determination of low- and sub-ppb (ng/g) concentrations of lead in infant formula by isotope dilution inductively coupled plasma mass spectrometry using ultrasonic nebulization. After addition of a known amount of 207Pb, samples were microwave digested and the ratio 207Pb/208Pb was measured in the digests. Agreement with certified values for lead in milk powder standard reference materials was good, and isotope dilution analysis using 206Pb yielded identical results for the standard reference materials. Lead concentrations determined for several infant nutritional products were verified by an independent method. Typically, relative standard deviations of <4% were obtained with this method for lead concentrations above 2 ppb. The recovery of 2 ng of lead from an aqueous standard carried through the microwave digestion was 104 ± 4%. Infant formula (containing 0.6 ppb lead) to which 0.4 ng of natural-abundance lead had been added, to simulate a formula containing 0.9 ppb lead, was analyzed by isotope dilution, and the result was 96 ± 18% of the theoretical value. Thus, differences of 0.3 ppb lead could be clearly distinguished, and the detection limit was estimated to be 0.1 ng lead per gram of infant formula. The keys to accuracy for this method are minimizing contamination and accurately determining the concentration of lead in the isotopically enriched standard.

Simultaneous Determination of Arsenic, Cadmium, Mercury, and Lead in Raw Ingredients, Nutritional Products, and Infant Formula by Inductively Coupled Plasma Mass Spectrometry: Single-Laboratory Validation

2016 ◽  
Vol 99 (3) ◽  
pp. 766-775 ◽  
Author(s):  
Lawrence H Pacquette ◽  
Anil Anumula
Keyword(s):  
Mass Spectrometry ◽  
Infant Formula ◽  
Inductively Coupled Plasma ◽  
Control Sample ◽  
Standard Reference Materials ◽  
Inductively Coupled ◽  
Icp Ms ◽  
Validation Parameters ◽  
Plasma Mass Spectrometry

Abstract A method was developed for the determination of As, Cd, Hg, and Pb in raw ingredients, nutritional products, and infant formula using inductively coupled plasma mass spectrometry (ICP-MS). Three raw ingredients (acid casein, maltodextrin, skim milk powder) and three standard reference materials [NIST 1548a (Typical Diet), NIST 1577c (Bovine Liver), NIST SRM 1568b (Rice Flour)] obtained from the National Institute of Standards and Technology were analyzed by two analysts using two ICP-MS instruments in different laboratories. NIST SRM 1568b was used as the control sample. All protocol validation parameters (intermediate precision, accuracy, linearity, quantitation limit, specificity, and robustness) were met. The overall precision (n = 8) for analyte concentrations (2.5–300 ng/g) ranged from 2 to 14% RSD. Spike recoveries ranged from 88 to109% for spike levels between 25 and 200%. The overall average concentration of As, Cd, Hg, and Pb measured in all three NIST SRMs were within the certified value ranges. Good linearity (correlation coefficient (r) = 0.9995 or better) was obtained for all analytes. Control chart results for 8 independent days showed that the method is robust (precision values of 10% and all points within ±3 σ were obtained). Excellent specificity was also demonstrated when the analytes were measured in the presence of high concentrations of the other concomitants.

Total Iodine in Infant Formula and Nutritional Products by Inductively Coupled Plasma/Mass Spectrometry: First Action 2012.14

2013 ◽  
Vol 96 (4) ◽  
pp. 798-801 ◽  
Author(s):  
Lawrence H Pacquette ◽  
Alan M Levenson ◽  
Joseph J Thompson ◽  
Dawn Dowell
Keyword(s):  
Infant Formula ◽  
Inductively Coupled Plasma ◽  
Internal Standard ◽  
Total Iodine ◽  
Method Performance ◽  
Inductively Coupled ◽  
Expert Review ◽  
Performance Requirements ◽  
Expert Review Panel ◽  
Plasma Mass Spectrometry

Abstract After an assessment of data generated from a single-laboratory validation study published in the Journal of AOAC INTERNATIONAL 95, 169–176 (2012), a method for determining the total level of iodine in infant formula and nutritional products was presented for consideration for adoption by AOAC during the AOAC Annual Meeting held September 30–October 3, 2012 in Las Vegas, NV. An Expert Review Panel on Infant Formula and Adult Nutritionals concluded that the method met the established standard method performance requirements, and approved the method as AOAC Official First Action. The method involves digestion of the sample with nitric acid in a closed vessel microwave oven, followed by determination by inductively coupled plasma/MS using tellurium as the internal standard. The method LOQ for total iodine was 1.5 μg/100 g, but a practical LOQ was used at 5 μg/100 g total iodine. The analytical range of the method was 5–100 μg/100 g total iodine. The recoveries from 15 spiked nutritional products ranged from 90 to 105%.

Method for the Determination of Total Selenium in a Wide Variety of Foods Using Inductively Coupled Plasma/Mass Spectrometry

2013 ◽  
Vol 96 (4) ◽  
pp. 786-794 ◽  
Author(s):  
Darryl Sullivan ◽  
Richard Zywicki ◽  
Mark Yancey
Keyword(s):  
Nitric Acid ◽  
Infant Formula ◽  
Inductively Coupled Plasma ◽  
Microwave Digestion ◽  
High Volume ◽  
Powdered Infant Formula ◽  
Inductively Coupled ◽  
Plasma Mass Spectrometry ◽  
Total Selenium

Abstract An optimized method for use in a high volume laboratory was developed and validated for the determination of total selenium in a wide variety of food products including infant formula. The method utilizes a single-stage, closed-vessel microwave digestion procedure with nitric acid. Upon completion of digestion, the solution is brought to volume with water. A dilution is prepared for analysis by adding methanol (MeOH) to an aliquot and then brought to volume by nitric acid diluent resulting in a 3% MeOH concentration. The amount of selenium is determined by inductively coupled plasma (ICP)/MS with the capability of removing argon-based polyatomic interferences. Experiments were conducted to validate the method by determining precision, accuracy, linearity, specificity, ruggedness, and robustness. The calculated practical reporting level for this method was 25.0 μg/kg. The method provided an average RSD of 2.03% during analysis of a wheat flour reference material and 2.73% during analysis of a powdered infant formula. The accuracy of the method for these materials was 98.6 and 105%, respectively. The method has also been used successfully on a variety of foods from various categories including fruits, grains, vegetables, protein, and dairy.

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