【摘要】 纳氏试剂分光光度法测定氨氮时,样品溶液的pH值对其吸光度影响很大,进而影响着分析结果,在一定条件下,显色后样品溶液的吸光度随其pH值的增大而增大,当pH值>12.59时,吸光度趋于稳定,因此在测定氨氮过程中,显色前须合理调节样品溶液的pH值,以保证显色后样品溶液的pH值>12.59,才能得到准确可靠的分析结果。更多还原

【Abstract】 The sample solution’s pH affects greatly the absorbance and determination result,when determining ammonia nitrogen by Nessler’s reagent photometry.In a certain condition,the absorbance increases with the pH,but when the pH exceeds 12.59,the absorbance tends to stability.Therefore,it is necessary to adjust the pH of sample’s solution and let pH be over 12.59.So the results of determination are accurate.更多还原