Comparison of LC-MS/MS and Enzymatic Methods for the Determination of Total Choline and Total Carnitine in Infant Formula and Milk Products
| Autor: | Brendon D. Gill, Harvey E. Indyk, Iain J McGrail, Tadashi Kobayashi, David C Woollard |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Adult
01 natural sciences Analytical Chemistry Choline chemistry.chemical_compound Milk products Tandem Mass Spectrometry Carnitine Lc ms ms medicine Environmental Chemistry Animals Humans Pharmacology chemistry.chemical_classification Chromatography 010405 organic chemistry 010401 analytical chemistry Infant Repeatability Infant Formula 0104 chemical sciences Enzyme Certified reference materials Milk chemistry Infant formula Agronomy and Crop Science Food Science medicine.drug Chromatography Liquid |
| Zdroj: | Journal of AOAC International. 103(5) |
| ISSN: | 1944-7922 |
| Popis: | Background Choline and l-carnitine are classified as pseudo-vitamins because of their conditionally essential status. As they are involved in multiple physiological metabolic pathways in the human body, they are routinely fortified in infant and adult nutritional formulas. Objective The performance of an LC-MS/MS method for the analysis of choline and carnitine, compared with enzymatic methods in routine use for the analysis of total carnitine and total choline, is described. Method Powder samples were reconstituted, with release of carnitine and choline facilitated by both acid and alkaline hydrolysis and the extract analyzed by LC-MS/MS. Quantitation was by internal standard technique using deuterium-labeled carnitine and deuterium-labeled choline. Results Method range, specificity, sensitivity, precision, recovery, accuracy, and ruggedness were assessed for milk powders, infant formulas, and soy- and milk-based nutritional products. Spike recoveries of 94.0–108.4% were obtained for both total carnitine and choline, and no statistical bias (α = 0.05) between measured results and certified values (choline: P = 0.36; free carnitine: P = 0.67) was found for NIST 1849a certified reference material (NIST1849a). Precision, as repeatability relative standard deviation (RSD), was 2.0% RSDr for total carnitine and 1.7% RSDr for total choline. Equivalent results for total choline and total carnitine were obtained by LC-MS/MS and enzymatic methods (n = 30). Conclusions The described LC-MS/MS method is fit for purpose for routine product compliance release testing environments. This validation study has confirmed that alternative enzymatic assays can be used with confidence in laboratories in which LC-MS/MS platforms are unavailable. Highlights An LC-MS/MS method was evaluated and found to be fit-for-purpose for routine product compliance release testing of infant formula. The LC-MS/MS method was compared with enzymatic methods for the analysis of total carnitine and total choline. Alternative enzymatic assays can be used with confidence in laboratories in which LC-MS/MS platforms are unavailable. |
| Databáze: | OpenAIRE |
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