title: Determination of Chloride in Infant Formula and Adult/Pediatric Nutritional Formula by Potentiometric Titration: Single-Laboratory Validation, First Action 2015.07.
abstract: A potentiometric method for determination of chloride was validated against AOAC Standard Method Performance Requirement (SMPR(®)) 2014.015. Ten AOAC Stakeholder Panel on Infant Formula and Adult Nutritionals (SPIFAN) matrixes, including National Institute of Standards and Technology (NIST) Standard Reference Material (SRM) 1849a, were tested in duplicate on 6 independent days. The repeatability (RSDr) ranged from 0.43 to 1.34%, and the intermediate reproducibility (RSDiR) ranged from 0.80 to 3.04%. All results for NIST SRM 1849a were within the range of the certified concentration (701 ± 17 mg/100 g). Recovery was demonstrated with two overspike levels, 50 and 100%, in the 10 SPIFAN matrixes. Samples were tested in duplicate on 3 different days, and all results were within the SMPR requirement of 95 to 105%. The LOQs of the method for powdered products and ready-to-feed or reconstituted products were 20 mg/100 g and 2.2 mg/100 mL, respectively. A wide analytical range from the LOQ to 99.5% chlorine content can be reached with an appropriate dilution factor, but in practice, the upper analytical value observed in routine matrix testing was approximately 1080 mg/100 g in skim milk powder. This is a rapid, simple, and reliable chlorine-testing method applicable to infant formula, adult nutritionals, and ingredients used in these dairy-based products, such as skim milk powder, desalted whey powder, whey protein powder, and whole milk powder.
authors.affiliation: Comprehensive Test Center of Chinese Academy of Inspection and Quarantine, Gao Bei Dian North Rd A3, Chao Yang District, Beijing, People's Republic of China.
authors.forename: Wu
authors.initials: W
authors.lastname: Bolong
authors.forename: Zhang
authors.initials: Z
authors.lastname: Fengxia
authors.forename: Ma
authors.initials: M
authors.lastname: Xiaoning
authors.forename: Zhou
authors.initials: Z
authors.lastname: Fengjuan
authors.forename: Sharon L
authors.initials: SL
authors.lastname: Brunelle
mesh_terms: D000328:Adult; D002712:Chlorides / Q000032:analysis*; D005504:Food Analysis; D005526:Food, Formulated / Q000032:analysis*; D006801:Humans; D007223:Infant; D041943:Infant Formula / Q000737:chemistry*; D007753:Laboratories; D009753:Nutritive Value; D011199:Potentiometry
chemical_list: D002712:Chlorides