Abstract:

Chinese cabbage was used as the sample to establish a method for determining nitrate, nitrite, phosphate, total phosphorus (TP) and total nitrogen (TN) through ultrasound-assisted extraction and ion chromatography (UAE-IC). The distribution of these compounds in different parts of Chinese cabbage was also investigated. The detection limits for nitrate, nitrite, phosphate, TP and TN were 0.015, 0.014, 0.030, 0.014 mg/L and 0.061 mg/L, respectively, at a sample injection volume of 20 μL using an elution system composed of Na2CO3 and NaHCO3. The determination coefficients of the developed linear equations of these analytes and the precision relative standard deviations (RSDs) were in the range of 0.9990 to 0.9999 and 0.22% to 0.94%. The spike recovery rates of these analytes were between 80.0% and 110.0%. This method is characteristic of simple operation, fast detection, and accurate and reliable results.

Key words: ion chromatography, ultrasound, Chinese cabbage, nitrogen, phosphorus