Development of a glass slide coated with molybdenum disulfide@graphene oxide-polystyrene as an extraction device for the extraction of polycyclic aromatic hydrocarbons in coffee

Abstract

This thesis develops a sample preparation technique using a new type of solid sorbent that is easy to prepare and use. It is developed using a molybdenum disulfide@grahene oxide?polystyrene coated on the glass slide surface and is used as a sorbent for extracting three types of polycyclic aromatic hydrocarbons, chrysene, benzo(b)fluoranthene, and benzo(a)pyrene. After extraction, targets were then subjected to qualitative and quantitative analyzed using high?performance liquid chromatography coupled with a diode array detector. Under the optimum conditions, a wide linear range was obtained from 2?2000 �g L?1 with limits of detection at 0.4 � (4.1�10?3), 1.5 � (2.1�10?2), and 4.2 � (5.4�10?2) �g L?1 for chrysene, benzo(b)fluoranthene, and benzo(a)pyrene, respectively. Six sorbents were prepared under the same condition at different time, the relative standard deviations of 3.4, 5.0 and 6.7% were obtained indicating a good sorbent?to?sorbent reproducibility. The developed method was then applied for the analysis of chrysene, benzo(b)fluoranthene, and benzo(a)pyrene contaminated in 10 instant coffee samples. Chrysene, the only target analytes was detected in 3 samples at a concentration of 3.3 � 0.6, 3.1 � 0.8, and 17.7 � 0.2 �g L?1 with the recoveries ranged from 78.3 � 4.9 to 109.8 � 1.2% and the relative standard deviations ranged from 5.1 to 6.8%.????????????????????????????????????????????????????????????????????????????????????????????????????? ??????????????????????????????????????????????????????????????????????????? ???????????????????????????????????????????????????????????????????? 3 ??????? ?????? ?????(??)??????????? ????????(??)????? ????????????????????????????????????????????????????????????????????????????????????????????????????????????????? ??????????????????????????????????????????????????????????????????????????????????? ????????????????????? ????? ????????????????????????????????????????????????????? 2?2000 ???????????????? (?????????????????????????????? 0.999) ????????????????????????? 0.4 � (4.1�10?3), 1.5 � (2.1�10?2) ??? 4.2 � (5.4�10?2) ???????????????? ????????????, ?????(??)??????????? ????????(??)????? ???????? ???????????????????????????????????????????? 6 ??? ????? ????????????????????????????????????? 3.4, 5.0 ??? 6.7 ????????????, ?????(??)??????????? ????????(??)????? ???????? ??????????????????????????????????????????????????????????????????? ??????, ?????(??)??????????? ????????(??)????? ???????????????????????????? 10 ???????? ??????????????????? ?????????????????????????? 3 ?????????????????????? 3.3 � 0.6, 3.1 � 0.8 ??? 17.7 � 0.2 ???????????????? ???????????????????????????????????????????????????????? 78.3 � 4.9 ??? 109.8 � 1.2 ??????????????????????????????????????????????? 5.1 ??? 6.8