AOAC SPIFAN Chlorate-01 Reviewer Form (November 2022)

FOR EXPERT REVIEW PANEL USE ONLY NOT FOR DISTRIBUTION

Some captions of tables do not reflect what the tables contain and are a bit confusing. I suggest considering the following:

Table 9: individual recovery values on samples used during validation.

Table 10 : Mean recoveries, RSD for chlorate at 0.005 mg/kg Table 11: Mean recoveries, RSD for chlorate at 0.05 mg/kg

Table 10 and 11 can be combined

Same for tables 12 and 13 as regards of perchlorate

2) Some clarifications on the approach used for validation would be needed.

In one hand, for matrices where blanks containing more than 30% of the target LOQ, the LOQ was estimated based on extrapolation of linear regression of S/N ratio and concentration to a theoretical S/N 10. According to tables 14 and 15, matrices validate with this approach were: plant based infant formula, whey protein concentrate, and soy protein isolate (with incurred values, according to table 9, at 0.1304 mg/kg chlorate, 0.0124 mg/kg chlorate and 0.2474 mg/kg chlorate & 0.0059 mg/kg perchlorate, respectively). In the case of whey protein concentrate (target LOQ is 0.01 mg/kg), therefore the incurred value is < 30% target LOQ (0.013), and therefore it could have been validated with spiking/recovery experiments. On the other hand, according to table 9 other matrices contained incurred amounts higher than 30 % LOQ, and were validated using spiking/recovery experiments.

- Cereal based baby food: 0.0299 mg/kg chlorate (30 % target LOQ = 0.0015 mg/kg) - Vegetables based baby food: 0.0138 mg/kg chlorate (30 % target LOQ = 0.0015 mg/kg) - Liquid milk: 0.0167 mg/kg chlorate (30 % LOQ = 0.0015 target mg/kg) - Sheep milk: 0.0183 mg/kg perchlorate (30 % LOQ = 0.0015 target mg/kg)

A clarification on the approach used for validation and the criteria for selecting this approach in each case should be provided.

Final Recommendation:

Recommended for first action after discussion and clarification on the LOQ estimation

2