Evaluation of X-ray fluorescence spectroscopy as a method for the rapid and direct determination of sodium in cheese

摘要: Cheese manufacturers indirectly determine Na in cheese by analysis of Cl using the Volhard method, assuming that all came from NaCl. This method overestimates actual content cheeses when replacers (e.g., KCl) are used. A direct and rapid for detection is needed. X-ray fluorescence spectroscopy (XRF), a mineral technique used mining industry, was investigated as an alternative cheese. An XRF developed compared with inductively coupled plasma optical emission (ICP-OES; reference cheese) analyzer. Sodium quantification performed multi-point calibration standards spiked NaCl ranging 0 to 4% (wt/wt). The concentration each (discs: 30 mm × 7 mm) quantified 3 methods. single laboratory validation performed; linearity, precision, limit detection, were determined. additional graph created made natural or process manufactured different ratios Na:K. Both K curves linear standards. variety commercial samples. data obtained agreement those ICP-OES analyzer most cheeses. did not accurately several samples, ICP-OES, likely due use unknown types Na-based emulsifying salts (ES). When curve specific ES this cheese, successfully predicted For cheeses, can be determined acceptable level repeatability, trueness 82 246 mg/100 g respectively. Calibration graphs should reflect range, ratio, salt type present measurement wide Commercial proprietary blends ES. We find worked actually