Vitamin B6 (Pyridoxine) Test

Method description

This is a microbiological assay employing the organism Saccharomyces uvarum to determine the quantity of vitamin B6 (pyridoxine, pyridoxal, and pyridoxpyridoxine) in food products and vitamin concentrates.

The ground, homogenized sample is dissolved or dispersed in an acidic extraction solution. The mixture is autoclaved at 121 – 123 °C to extract vitamin B6. The pH of the extract is adjusted to 4.4 and diluted with a basal medium containing all required growth nutrients for the microorganism except vitamin B6. The mixture is inoculated with the microorganism and incubated for 22 hours at 30°C. The growth response of the microorganism is compared quantitatively to that of known standard solutions of vitamin B6.

The result is expressed as vitamin B6 (pyridoxine). The method is semi-automated utilizing an automated pipettor system and an automated plate reader system.

Acceptable matrices

This method is applicable to cereals, beverages, and dairy products containing added vitamin B6 and/or other free forms of vitamin B6.

Unacceptable matrices

This method is not designed for use on vitamin concentrates.

Limit of quantitation

0.002 mg/100g to 4000 mg/100 g

Equipment

Automated pipettor system
Automated plate reader system

Method reference

AOAC 961.15, 985.32, 960.46

Reportable unit

mg/100g

Sample size requirements

10 grams

Information required by submitter

Please supply an estimate with your sample.

Additional information

This test is ISO/IEC 17025 accredited through A2LA, Certificate # 2769.01.

This method is not designed for use on vitamin concentrates.