Objective  To evaluate the ability for the detection of vitamin B₁ and vitamin B₂ in dairy products in laboratories of disease prevention and control institutions across China for improving the laboratories′ ability for such detections.

  Methods  Assessment samples for vitamin B₁ and vitamin B₂ detection were distributed to 35 laboratories of disease prevention and control institutions at province or municipality level between June and November, 2017. Then the laboratories were required to detect vitamin B₁ and vitamin B₂ of the samples with national standard method described in GB 5009 series.

  Results  Of the laboratories involved in the study, 32 reported results of vitamin B₁ detection (16 for low concentration samples and 16 for high concentration samples) and 33 reported those of vitamin B₂ detection (16 for low and 17 for high concentration samples). For low concentration vitamin B₁ sample detections, the reported maximum and minimum concentration are 0.747 mg/100 g and 0.507 mg/100 g; the variation coefficient is 8.92%; and 87.5% (14) of the laboratories reported satisfactory results. For high concentration vitamin B₁ sample detections, the reported maximum and minimum concentration are 0.968 mg/100g and 0.550 mg/100 g; the variation coefficient is 14.08%; and 93.8% (15) of laboratories reported satisfactory results. For low concentration vitamin B₂ detections, the reported maximum and minimum concentration are 1.19 mg/100 g and 0.853 mg/100 g; the variation coefficient is 8.94%; and 93.8% (15) of the laboratories reported satisfactory results. For high concentration vitamin B₂ detections, the reported maximum and minimum concentration are 1.40 mg/100 g and 0.686 mg/100 g; the variation coefficient is 15.53%; and 76.5% (13) of the laboratories reported satisfactory results.

  Conclusion  The results are generally satisfactory for the quality assessment on detections of vitamin B₁ and B₂ in dairy products for laboratories in disease prevention and control institutions at different administrative levels in China and the detection ability for some of the laboratories needs to be improved.