Calculationof the Detection Limits in Water Quality Analysis Method

The detection limits of the water quality analysis method were calculated and discussed with case. The conclusions were that at the present,the detection limits of the method were mainly calculated by the standard deviation of parallel determination of multiple blank samples; as a study case,the detection limits of alkaline potassium persulfate digestion UV spectrophotometric method which detected total nitrogen in water was calculated,the three times the standard deviation of 0. 049 mg/L of blank samples concentration was regarded as the detection limits of the method,which was equal to that in the standard method of 0. 05 mg/L; the concentration of 0. 01 absorbance excluding blank value was also regarded as the detection limits,different calibration curve which were different; and the detection limit of ion-chromatography was 0. 002 mg/L,which was lower than that of Mo-Sb anti-spectrophotometer(0. 01 mg/L), decreasing one order of magnitude.