Abstract: The contents of calcium （Ca） and phosphorus （P） in premix feed directly affected the growth, development and health status of shrimp. Traditional chemical analysis methods required complicated pre-treatment process for shrimp premix feed and always took several hours to obtain test results. In this study, a simple and fast analysis method, energy dispersive X-ray fluorescence spectrometry （ED-XRF）, was used to assess the contents of Ca and P in shrimp premix feed, and the test results of the samples were obtained within a few minutes. The pre-treatment process of ED-XRF method only included comminution and squash. The limit of detection of ED-XRF method for Ca and P were 43 mg/kg and 163 mg/kg, respectively, and the limit of quantification of that for Ca and P were 142 mg/kg and 544 mg/kg, respectively. Six consecutive determinations of shrimp premix feed sample 3^# were conducted by ED-XRF method. The range of the continuous measurement data of Ca and P were 0.159% and 0.013%, respectively, which were smaller than the repeatability critical difference of CrR₉₅ （6） for the contents detection of Ca （0.239%） and P （0.031%） in the recommended national standard, indicating that the ED-XRF method met the requirements of the recommended national standard for the determination of Ca and P contents in feed. By analyzing the contents of Ca and P of ten shrimp premix feed samples which were measured by national standard methods, we found that the relative differences in measured value of Ca and P contents between ED-XRF method and recommended national standard method did not exceeded 4.55%. To sum up, the ED-XRF method had high precision and accuracy, and it could be used in monitoring the addition of Ca and P for shrimp premix feed production enterprises.

Key words: energy dispersive X-ray fluorescence spectrometry method, shrimp premix feed, calcium content, phosphorus content, rapid determination