Development of two reference materials for all trans-retinol, retinyl palmitate, α- and γ-tocopherol in milk powder and infant formula

Abstract

Vitamins are important food constituents that can be present in almost every foodstuff. Food quality and safety depends on food surveillance by reliable quantitative analysis enabled by appropriate quality control. Certified matrix reference materials are versatile tools to support quality assurance and control. However, in the case of vitamins, which are important in various foods, there is a lack of matrix reference materials. Two certified reference materials for the determination of all-trans-retinol, retinyl palmitate, and α- and γ-tocopherol in milk powder and infant formula have been developed by the National Institute of Standards, Egypt. This article presents the preparation, characterization, homogeneity, and stability testing as well as statistical treatment of data and certified value assignment. The assignment of the certified values and associated uncertainties in the prepared natural-matrix reference materials were based on the widely used approach of combining data from independent and reliable analytical methods.

Technical note: Development and validation of an HPLC method for the quantification of tocopherols in different types of commercial cow milk

“…Tocopherols are among the major fat-soluble antioxidants and they exist in nature in 4 variants, namely α-, β-, γ-, and δ-tocopherol (T); together with tocotrienols, they belong to vitamin E compounds (Ju et al, 2010;Shehata et al, 2015). Both in vivo and in vitro studies demonstrated that tocopherols have direct and indirect antioxidant activity, and human epidemiological studies showed an association between low vitamin E status and an increased risk of cancer and heart diseases (Galli et al, 2017).…”

Preparation of Quality Control Material for Assuring Quality of Electrical Conductivity Measurements in Soil

“…The results of the homogeneity study were analyzed [ Fig.1] and uncertainty of the material was estimated and combined with other sources to estimate expanded uncertainty [11][12][13]. The uncertainty u bb was estimated from the difference between the total variability and the within bottle variability [8,[14][15][16][17][18][19]…”

Variation Quality and Kinetic Parameter of Commercial n-3 PUFA-Rich Oil during Oxidation via Rancimat

“…Aliquots of 10 µL of the filtrate were injected into the injection port and analyzed with HPLC (Hitachi L-2130 pump, Hitachi, Tokyo, Japan). The remaining procedures were carried out as previously reported [ 34 ] using an HPLC attached to a detector L-2400 UV and a Hitachi L-2130 pump. An RP-18GP250 Mightysil column ( l = 250 mm; i.d.…”