Semiautomated method for niacin and niacinamide in food products: collaborative study.

A collaborative study was conducted comparing a semiautomated colorimetric niacin method with a manual colorimetric and a microbiological method for 10 food products. Seven laboratories used the microbiological method, 7 laboratories used the manual colorimetric method, and 6 laboratories used the semiautomated method. The semiautomated method was more repeatable within a laboratory and more reproducible between laboratories than was either of the other methods. The semiautomated method results compared favorably with both the microbiological and manual colorimetric method results.