Flour was digested with a mixture of concentrated nitric acid, sulfuric acid and perchloric acid (10:0.5:2, v/v and analysed using an atomic absorption spectrophotometer (GBC 904AA; Germany).
Flour was digested with a mixture of concentrated nitric acid, sulfuric acid and perchloric acid(10:0.5:2, v/v and analysed using an atomic absorption spectrophotometer (GBC 904AA; Germany).