Simultaneous quantification of light elements in food based on portable energy dispersive X-ray fluorescence (p-XRF) combined with second-order calibration algorithm

In order to accurately quantify the content of light elements in food samples, a method based on portable energy dispersive X-ray fluorescence (p-XRF) technology combined with second-order calibration algorithm was proposed to simultaneously quantify phosphorus (P), sulfur (S), potassium (K) and calcium (Ca) in different food samples. Firstly, the XRF response signal matrix of each food sample was obtained by changing the test current and voltage. Secondly, the alternating penalty trilinear decomposition (APTLD) algorithm was used to analyze the three-way data array stacked by multiple samples. The results showed that second-order calibration algorithm could accurately extract the spectral signal of the target element even if there were serious background interference and signal overlap. The predicted recovery rates of the target elements in the food samples are 82 %–119 %. The LOD and LOQ of P, S, K, and Ca are 3, 3, 20, 8 ppm and 9, 11, 68, 26 ppm, which proves that this method can accurately quantify light elements in food samples. This study demonstrated that p-XRF combined with second-order calibration is an effective method for the determination of light elements in food and has broad practical application prospects.