Analisis Kadar P Dan N dalam Pupuk NPK dengan Metode Spektrofotometri Uv-Vis Dan Metode Kjeldahl

Abstract

Analysis of phosphorus (P) and nitrogen (N) content in NPK fertilizer has been carried out using the UV-Vis spectrophotometry and Kjeldahl methods. This study aimed to determine the phosphorus and nitrogen content in NPK fertilizer according to the quality standards specified in SNI 2803:2012.Phosphorus content was measured using the UV-Vis spectrophotometry method, based on the formation of a yellow-colored phosphomolybdovanadate complex, with absorbance measured at wavelengths of 400–420 nm. Meanwhile, nitrogen analysis was performed using the Kjeldahl method, involving digestion, dilution, distillation, and titration steps to determine the total nitrogen content.The results showed that NPK fertilizer samples numbered 9, 10, and 11 met the minimum requirements specified in the SNI standard, with a minimum phosphorus content of 6% and nitrogen content of 6%. The phosphorus content in these samples was found to be 16.26%, 12.44%, and 16.98%, while nitrogen content was 11.02%, 11.01%, and 12.10%, respectively.Based on these results, both the UV-Vis spectrophotometry and Kjeldahl methods proved to be effective, accurate, and reliable for analyzing macro nutrients in compound fertilizers.