Low Lactose ERP - Review Book

AOAC SMPR ERPs - 2019 METHOD REVIEW FORM

Submission Date

2019-09-05 18:12:35

Name

John Szpylka

E-mail

john.szpylka@mxns.com

Organization

Merieux NutriSciences

Title of Method

Lactose, free and low, Profile by High Performance Anion Exchange Chromatography with Pulsed Amperometric Detection (HPAEC-PAD): A Single- Laboratory (SLV) Investigation

AOAC Candidate Method Number (e.g. ALN-01)

LAC-001

Applicable SMPR

2018.001

I. Summary of the Method

The method is based on a broader multiple sugar analysis with this method submission focusing on the lactose disaccharide. For each sample, two subsamples are used for this analysis. The method abstract states sugars are extracted from both solutions using an aqueous-ethanol solution; however the method protocol only states water is used. The ethanol must be confirmed since ethanol is needed to denature enzymes present in the sample, a criteria listed in the SMPR. After extraction, the solutions are clarified using Carrez solutions. One subsample is treated with B-galactosidase to remove lactose. After HPAEC-PAD separation/quantitation, the difference in the peak areas at the lactose retention time is used to quantify the lactose in the sample. All SMPR criteria are met; however, the method protocol only states water is used to extract lactose. Since possible conflicting enzymes could decrease lactose recovery, the use of ethanol as listed in the abstract must be confirmed. The authors did account for an error in the SMPR LOD (stated as 5 mg/100mg or 5%) with the method achieving an LOD of 0.005% lactose.

II. Review of the Method Only 1. Does the applicability of the method support the applicability of the SMPR? If not, please explain what is missing. 2. Does the analytical technique(s) used in the method meet the SMPR? If not, please specify how it differs from what is stated in the SMPR.

The technique has the required sensitivity and accounts for potential lactose chromatographic co-elutants.