Determination of seven plant nutritional elements in potassium dihydrogen phosphate fertilizer from northeastern China

Contents of seven plant nutritional elements in potassium dihydrogen phosphate fertilizer were determined by ICP-MS. Correlation coefficients of the detected elements changed between 0.9631 and 0.9999, the limits of detection range from 0.18 to 0.77 μg/L, and relative standard deviations range from 1.17% to 3.82% for all the elements, ICP-MS (Inductively Coupled Plasma-Mass Spectrometry) is a good method to determine plant nutritional elements simultaneously. Data showed that brand 1 is a real KH₂PO₄ fertilizer, but P and K concentrations are obviously lower than the labeled value; another brand contained little KH₂PO₄, so this fertilizer is a false fertilizer. We can know that KH₂PO₄ fertilizers contain some other plant nutritional elements, such as B, Si and Zn, so KH₂PO₄ fertilizers not only provide K and P but also some trace elements.