title: Simultaneous determination of vitamins D2 and D3 by electrospray ionization LC/MS/MS in infant formula and adult nutritionals: First Action 2012.11.
abstract: A method was developed for the analysis of vitamins D2 and D3 in a variety of nutritional products. To extract vitamins D2 and D3 from products containing substantial amounts of fat, a saponification with alcoholic potassium hydroxide is required to release the vitamin D. Trideuterium-labeled vitamin D is added to the sample prior to saponification, and quantitation is achieved using linear regression of the ratio of peak response for 2H3-D and vitamin D. Acceptable linearity was achieved between 0.6 and 27 microg/100 g with a correlation requirement of >0.999. The method detection limit of 0.02 microg/100 g was verified by spiking placebo products carried through the saponification and extraction steps of the method. At the quantitation limit (0.12 microg/100 g), the signal was easily distinguished from the background. Vitamin D3 spike recoveries ranged from 107 to 119% at the low level and 104 to 116% at the high-level spike. Vitamin D2 recoveries were 105 to 116% and 91 to 110% for the low- and high-level spikes, respectively. SRM 1849a has a certified concentration of 11.1 +/- 1.7 microg/100 g; using this standard reference material, the range of 9.4 to 12.8 microg/100 g was met on each of the 6 days. Method repeatability, determined in 12 vitamin D3 product matrixes over 6 days, ranged from 3.9 to 48%. The adult nutrition-milk protein sample was the most notable; it failed within-day, as well as day-to-day, precision requirements. There was no attempt to optimize the sample preparation to accommodate any problem matrix.
authors.forename: Donald L
authors.initials: DL
authors.lastname: Gilliland
authors.forename: Charles K
authors.initials: CK
authors.lastname: Black
authors.forename: James E
authors.initials: JE
authors.lastname: Denison
authors.forename: Charles T
authors.initials: CT
authors.lastname: Seipelt
authors.forename: Steve
authors.initials: S
authors.lastname: Baugh
mesh_terms: D000328:Adult; D000388:Air; D000438:Alcohols / Q000737:chemistry; D000818:Animals; D002762:Cholecalciferol / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D002853:Chromatography, Liquid / Q000379:methods*; D003903:Deuterium / Q000737:chemistry; D004872:Ergocalciferols / Q000032:analysis*; D005504:Food Analysis / Q000379:methods*; D005526:Food, Formulated / Q000032:analysis*; D006801:Humans; D006878:Hydroxides / Q000737:chemistry; D041943:Infant Formula / Q000737:chemistry*; D007231:Infant, Newborn; D008892:Milk / Q000737:chemistry; D017680:Potassium Compounds / Q000737:chemistry; D015203:Reproducibility of Results; D012997:Solvents / Q000737:chemistry; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D000438:Alcohols; D004872:Ergocalciferols; D006878:Hydroxides; D017680:Potassium Compounds; D012997:Solvents; D002762:Cholecalciferol; D003903:Deuterium; C029943:potassium hydroxide