Gravimetric determination of ash in foods: NMKL collaborative study.

A gravimetric method for the determination of ash was collaboratively studied in 14 laboratories. The food is ashed at 550 degrees C to constant weight and the ash is determined by weighing. Seven samples of various food commodities with estimated ash contents varying between low and high (0.07-8.0 g/100 g) were included in the study. The relative standard deviations for reproducibility varied, ranging from 1.0 and 1.3 for ash contents of 7.2 and 8.0 g/100 g, to 11 +/- 1% for low ash contents of 0.07 and 0.27 g/100 g.