Drugs of abuse screening in betel nuts with slaked lime using HPLC-MS/MS instrument

Chewing betel nuts is becoming common, especially in southern Taiwan. However, the problems in clinical medicine, epidemiology, social costs, and environmental impact, have become issues in domestic public health. Chewing betel nut can cause periodontal disease, submucosal fibrosis, oral leukoplakia, and oral cancer. Moreover, white and red slaked lime are indispensable seasonings for betel nuts in the market. The difference between the two is that the red slaked lime can be combined with sweetening, condiments, or flavoring together with betel nuts. It suppresses the bitterness and astringency of the fruit and increases the flavoring and taste. In recent years, drug dealers have added drugs of abuse in slaked lime to make consumers addicted. Therefore, the purpose of this study is to develop a liquid chromatography with mass spectrometry to detect illegal drugs contained in commercially available slaked lime in betel nuts. After sampling with ultrasonic extraction and solid-phase extraction clean-up system, 20 drugs of abuse in slaked lime was column separated by Phenomenex Kinetex F5 core-shell (50x2.1 mm, 1.7 µm), and were detected in multiple reaction monitoring modes by Agilent 6470 triple quadrupole. The total run time of the system for sample extraction, analytical chromatography, and re-equilibration, was within 30 min. The method provided linear ranges from 1.0 to 500 ng/ml for illicit drug compounds, and the linearity was over 0.99. The limit of detection and limit of quantification for mass spectrometry were 0.4 and 1.0 ng/ ml, respectively. The accuracy and precision analysis of the method were conducted under repeatable conditions on different days. Intra-day and inter-day precision values were between 78 to 113 % and accuracy values between 78 to 93 %. The extraction recoveries range 78 to 81 %, and matrix effect range from 65 to 72 % at three quality control (QC). The method validation findings were reproducible and successfully applied for routine analysis of drugs of abuse analysis in betel nuts.