Determination of Lactose in Lactose-Free and Low-Lactose Milk, Milk Products, and Products Containing Dairy Ingredients by the LactoSensVR® Amperometry Method: Final Action 2020.01

Background: The LactoSensVR (R) method was previously shown to have acceptable accuracy and repeatability precision as required by AOAC Standard Method Performance Requirements (SMPRV (R)) 2018.009 for determination of lactose in low-lactose or lactose-free milk, milk products, and products containing dairy ingredients and was awarded Official Method of Analysis(SM) (OMA) First Action status in 2020. Objective: The method was subjected to a multilaboratory validation (MLV) study to evaluate the reproducibility precision of the method. Methods: Fourteen validation materials were provided to 15 laboratories in seven countries as blind duplicates. The materials ranged from 0 to 173 mg/100 g lactose. Each laboratory analyzed the blind duplicates according to OMA 2020.01. The data were analyzed for repeatability and reproducibility precision. Results: RSDr values varied from 2.81 to 8.76%, and RSDR values varied from 4.25 to 12.5%. When sorted by category and concentration range, these results met the repeatability and reproducibility criteria required by SMPR 2018.009. Conclusions: The data generated in the MLV support the adoption of OMA 2020.01 as Final Action status. Highlights: The LactoSensR method, as described by OMA 2020.01, provides an accurate and precise determination of lactose in a variety of low-lactose and lactose-free milk, milk products, and products containing dairy ingredients in minutes.