Simultaneous determination of borax and polyphosphates content in food by liquid chromatography inductively coupled plasma mass spectrometry (LC-ICP-MS)

Abstract

A new method based on LC-ICP-MS technique has been developed and validated for the simultaneous determination of borax and polyphosphates (phosphate, pyrophosphate, tripolyphosphate) in foods. The analytes were extracted from the samples with 18 mM sulfuric acid solution using ultrasonic vibration extraction technique before being filtered and analyzed by LC-ICP-MS system. The method was validated with calibration curves that have the coefficient of determination (R2) higher than 0.995. The method limits of detection (LOD) of borax, phosphate, pyrophosphate (Pyro-P), and tripolyphosphate (Tripoly-P) were in the range of 2.5 to 15.0 mg/kg. The recoveries were in the range of 86.0 to 107.0% and the relative standard deviations were below 5.23%. A total of 83 samples of cereal, meat, and seafood-based food were analyzed for research purposes. The results did not indicate a risk of using borax and polyphosphates in most rice products. Meanwhile, meat products including pork paste and roasted pork sold in traditional markets had a borax detection rate of over 60%. This study showed that there was still a risk of using borax in food processing and the use of polyphosphates in food products collected in some districts in Hanoi city.