液态奶中镁元素原位在线检测方法研究OA北大核心CSTPCD

Magnesium(Mg)represents one of the important nutritional components in milk.Howev-er,its detection methods require cumbersome sample pretreatment,which is inadequate for the high-throughput online analysis of trace elements.In this regard,this work developed a novel meth-odology that was named as ultrasonic spraying laser-induced breakdown spectroscopy(US-LIBS).In the US-LIBS,the techniques of ultrasonic spraying and ultra-short focus laser-induced breakdown spectroscopy were combined to avoid the plasma quenching,thus enhancing the stability and intensi-ty of the signal greatly.Benefiting from the instantaneous phase transition technology,US-LIBS can achieve in situ analysis of trace elements in milk samples within seconds without any pretreatment of the milk samples.This enables the intelligent assessment of dairy product quality and safety in an effi-cient way.In order to improve the detection accuracy of US-LIBS,the algorithm of reweighted-char-acteristic spectrum algorithm(RCSA)was also developed to extract the spectral bands of Mg element from the complicated and fluctuant matrix interference.Moreover,the RCSA algorithm utilizes its flexible weighting distribution to guarantee the integrity of spectral information,thus preventing the loss of crucial information bands.As a result,the RCSA algorithm exhibits a notably superior quanti-tative accuracy and reliability than those of other variable selection algorithms.In the validation sam-ples,the limit of detection and r2 of Mg were 0.3 mg/kg and 0.97,respectively.The results reveal that the US-LIBS is a promising online analysis tool for smart manufacturing of dairy products,which may well extend to any other liquid systems as well.