Comparison of determination methods for nitrate content in vegetables
The nitrate content in vegetables was used to be determined by hydrochloric acid naphthyl ethylenediamine method,phenol method and double wavelength method.The precision and accuracy of the three methods through detecting their variation coefficients and the recoveries of standard addition.The results showed that the variation coefficient and recovery of standard addition of the hydrochloric acid naphthyl ethylenediamine method was the highest,and the values was 0.16% and 106%～109%.The parameters of double wavelength method was little lower than the former,and they were 0.26% and 95%～109% ;the parameters of the phenol method was the lowest,and they were 2.98% and 90%～95%.But when the operation steps and reagents' safety were considered,the double wavelength method was concluded as the safest and fastest method for nitrate determination in vegetables.