PMID- 36528904 OWN - NLM STAT- MEDLINE DCOM- 20230103 LR - 20230111 IS - 1873-3778 (Electronic) IS - 0021-9673 (Linking) VI - 1688 DP - 2023 Jan 11 TI - Direct solidification of switchable-hydrophilicity salicylic acid: A design for the on-site dispersive liquid-liquid microextraction of benzoylurea insecticides in water and honey samples. PG - 463710 LID - S0021-9673(22)00901-3 [pii] LID - 10.1016/j.chroma.2022.463710 [doi] AB - This study describes the development of a fully manual method for on-site dispersive liquid-liquid microextraction based on the direct solidification of switchable-hydrophilicity salicylic acid (on-site DLLME-DSSA) coupled with high-performance liquid chromatography with an ultraviolet detector (HPLC-UVD) and its utilization for the detection of benzoylurea insecticides (BUs) in water and honey samples. Salicylic acid (SA), a switchable hydrophilic aromatic acid, was used as an extraction solvent. It can be converted into the hydrophobic/hydrophilic forms in pH-changeable solutions, facilitating facile and effective dispersion and phase separation. Moreover, the melting point of SA (significantly higher than room temperature) enables its direct solidification without an ice-water bath, facilitating its collection by filtration. The dispersion, separation, and collection of the extraction solvent were carried out entirely in a plastic syringe without requiring special apparatus or additional energy. Univariate and response surface analyses were used to optimize various parameters of the on-site DLLME-DSSA method. Under optimal conditions, the limits of determination (LODs) were 1.50 microg L(-1) and 0.03-0.09 mg kg(-1) in water and honey, respectively. The relative standard deviations (RSDs) for inter-day (n = 5) and intra-day (n = 5) precision were