International Journal of Biomedical Science & Bioinformatics
Author(s) : KRISANA JITMANEE, ORN-ANONG ARQUEROPANYO, TERABOON POJANAGAROON , WACHIRAPORN KHEOWMUNG
Simultaneous extraction of three residual pesticides from different classes: dimethoate, carbaryl and fenvalerate, as representatives of organophosphate, carbamate and pyrethroid, from Tangerine (Citrus reticulata Blanco) peel was developed. The methodology was carried out by means of solvent extraction in ultrasonic bath. After that the extract was evaporated to near dryness on a vacuum rotary evaporator (40±1°C). The residue was then redissolved and followed by C18 - solid phase extraction (SPE) clean-up step. Typically, the parameters influencing the extraction such as extracting solvent, sonication time and the clean-up step condition were investigated. The determination was performed by high performance liquid chromatography (HPLC) equipped with ultraviolet detector (UV) and liquid chromatography/mass spectrometry (LC/MS). Average percentage recoveries of dimethoate, carbaryl and fenvalerate were found to be 91%, 80% and 97%, respectively. The precision with relative standard deviation (R.S.D) ranged from 0.63 - 4.19% for intra-day (n = 8) and from 0.57 - 4.90 % for inter-day (n = 8, 6 days).