Abstract:Objective To determine boron in foods from Guangzhou by curcumin spectrophotometry.Methods Samples were pretreated by dry ashing after alkalified with 1% Na2CO3 and then turned into boric acid under acidic condition.A red compound was formed by the reaction of boric acid with curcumin,which was quantified by spectrophotometry.Results A good linearity was obtained in the range of 0-1 μg/ml,r=0.999 6,and the detective limit was 0.017 μg/ml.The relative standard deviation was 0.09%-6.11%,and the mean recovery was 88.9 %-103.6%.Boron contents in 68 kinds of food from Guangzhou were 2.99-34.73 mg/kg,in fruits were 0.10-4.50 mg/kg and in vegetables were 0.09-2.91 mg/kg.Boron contents in most other samples were low except in 3 samples.Conclusion The method needs only general equipment,and its repeatability,sensitivity and accuracy could meet the requirements of boron analysis in different kinds of food.The concentration of boron in dried fruits,beans and vegetables was higher,and that in fish,meat,egg and grain was lower.Some foods may be added with borax or boric acid unlawfully.