Results Multi-Laboratory Trial ISO/CD 22184-IDF/WD 244: Milk and Milk Products-Determination of the Sugar Contents-High-Performance Anion Exchange Chromatography Method with Pulsed Amperometric Detection.

BACKGROUND: In this international Multi-Laboratory Trial (MLT) the precision data and the accuracy of the ISO/CD 22184 IDF/WD 244 analytical method for the quantification of 6 different mono- and disaccharides (galactose, glucose, fructose, sucrose, lactose, and maltose) in milk and milk products with high-performance anion exchange chromatography with pulsed amperometric detection (HPAEC-PAD) are established. OBJECTIVE: Thirteen different laboratories participated (located in New Zealand, the United States, and Europe). The study was divided into two parts. First, the learning/familiarization part in which the participants got experienced with the method. After successfully completing this part, the participants were allowed to continue with the second part of this trial: the analyses of the seven blind MLT duplicate samples. METHOD: The selected seven MLT samples comprise five MUVA reference dairy samples, one NIST-certified infant formula and one industrial sample. In the Tables S-1 to S-6 the results of this MLT study have been summarized per sugar. There is a very good agreement between the MUVA and NIST-certified sugar contents in the MLT samples and in the MLT established sugar contents in those MUVA and NIST samples. RESULTS: This demonstrates that the accuracy of the newly developed HPAEC-PAD method is very good. CONCLUSIONS: Certificates of analysis were available for both the MUVA samples and the NIST sample. There is a very good agreement between the by MUVA- and NIS-certified sugar contents in the MLT samples and the corresponding in the MLT established sugar contents. This demonstrates that the accuracy of the HPAEC-PAD method is very good. In the IDF/ISO Analytical Week in June 2019 in Prague the report on the MLT study were discussed and adopted.

The Determination of Sugars in Dairy Products: Development of a New Standard Method for the International Dairy Federation and the Internal Organization for Standardization.

A method using high-performance anion-exchange chromatography (HPAEC) with a pulsed amperometric detector (PAD) for the determination of mono- and disaccharides is described. The method was accepted by the International Dairy Federation and the Internal Organization for Standardization as a new work item for the determination of sugars in dairy matrixes, and the Milk and Milk Products technical committee of ISO/TC 34/SC 5 accepted the topic "Milk and milk products - Determination of the sugar contents - High-performance anion-exchange chromatographic method (HPAEC-PAD)" as a new work item. The proposed method consists of an aqueous ethanol extraction of the sugars in the dairy sample, followed by clarification with Carrez I and II reagents. The clarified filtrate is diluted and then directly introduced in the HPAEC-PAD system for quantification of the sugars. A single-laboratory validation of the proposed method has been scheduled for spring 2017.

Dual-Laboratory Validation of a Method for the Determination of Fructans in Infant Formula and Adult Nutritionals: First Action 2016.14.

Until recently, only two AOAC Official MethodsSM have been available for the analysis of fructans: Method 997.08 and Method 999.03. Both are based on the analysis of the fructan component monosaccharides (glucose and fructose) after hydrolysis. The two methods have some limitations due to the strategies used for removing background interferences (such as from sucrose, α-glucooligosaccharides, and free sugars). The method described in this paper has been developed to overcome those limitations. The method is largely based on Method 999.03 and uses combined enzymatic and SPE steps to remove the interfering components without impacting the final analytical result. The method has been validated in two laboratories on infant formula and adult nutritionals. Recoveries were in the range of 86-119%, with most being in the range of 91-104%. RSDr values were in the range of 0.7-2.6%, with one exception when the fructan concentration was close to the LOQ, resulting in an RSDr of 8.9%. The performance is generally within the requirements outlined in the AOAC Standard Method Performance Requirements (SMPR® 2014.002), which specifies recoveries in the range of 90-110% and RSDr values below 6%.