抄録
On November 13, 2007, Japan’s Ministry of Health, Labour and Welfare established an official analytical method for detecting four fungicides̶imazalil (IMZ), thiabendazole (TBZ), orthophenylphenol (OPP), and diphenyl (DP)̶on disposable chopsticks. According to this method, 20% ethanol is used as a food simulant, and disposable chopsticks are heated in this solution at 60°C for 30 min. After filtering the eluate, TBZ, OPP, and DP are analyzed using high-performance liquid chromatography (HPLC) with a fluorescence detector, while IMZ is assessed separately under different conditions using a photodiode array detector, making this process time consuming. If any of the fungicides are detected, a confirmation test is conducted using gas chromatography–mass spectrometry (GC-MS). In addition to the HPLC analysis of the chopstick eluate, the method requires a separate elution test using methanol, complicating the testing process. To address these challenges, in the current study, a solid-phase extraction column was used to purify the chopstick eluate, enabling its use for the HPLC analysis and GC-MS confirmation. Additionally, diluting the purified solution tenfold with the HPLC mobile phase containing an ion-pair reagent enhanced the DP sensitivity and quantification capability of HPLC. Overall, the proposed approach improved the quantitative analysis of fungicides on disposable chopsticks while simplifying the testing process and enhancing its reliability.
