title: Determination of Chloride in Infant Formula and Adult/Pediatric Nutritional Formula by Automated Potentiometry: Single-Laboratory Validation, First Action 2015.08.
abstract: A direct potentiometric method involving titration against a standard volumetric silver nitrate solution using a silver electrode to detect the end point was evaluated for the determination of chloride in infant formula and adult/pediatric nutritional formula. It was assessed for compliance against AOAC Standard Method Performance Requirements (SMPR®) established by the AOAC Stakeholder Panel on Infant Formula and Adult Nutritionals (SPIFAN). A single-laboratory validation (SLV) study was conducted as a first step in the process to validate the method. In this SLV, 17 SPIFAN matrixes representing a range of infant formula and adult nutritional products were evaluated for their chloride content. The analytical range was found to be between 1.4 and 1060 mg/100 g reconstituted product or ready-to-feed (RTF) liquid. The LOQ was estimated as 1.4 mg/100 g. Method repeatability was between 0.03 and 1.60% in the range of 20 to 167 mg/100 g RTF, and intermediate precision was between 0.09 and 2.77% in the same range. Recovery values based on spiking experiments at two different levels of chloride ranged from 99.0 to 103% for 15 different SPIFAN products. Evaluation of trueness was performed on National Institute of Standards and Technology Standard Reference Material 1849a (Infant/Adult Nutritional Formula) and showed 97.2% of the theoretical value, with no bias at the 95% confidence level. Based on the results of the SLV, the method met the SMPR and was approved as a First Action method by the AOAC Expert Review Panel on Infant Formula and Adult Nutritionals on March 17, 2015.
authors.affiliation: Nestlé Quality Assurance Center, 6625 Eiterman Rd, Dublin, OH 43017, USA.
authors.forename: Gregory G
authors.initials: GG
authors.lastname: Jaudzems
mesh_terms: D000328:Adult; D057205:Automation, Laboratory; D002648:Child; D002712:Chlorides / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid / Q000592:standards*; D005526:Food, Formulated / Q000032:analysis*; D017408:Guidelines as Topic; D006801:Humans; D007223:Infant; D057230:Limit of Detection; D011199:Potentiometry / Q000379:methods / Q000592:standards*; D011208:Powders; D015203:Reproducibility of Results; D012835:Silver Nitrate / Q000737:chemistry
chemical_list: D002712:Chlorides; D011208:Powders; D012835:Silver Nitrate