Flow injection chemiluminescence determination of ethion and computational investigation of the adsorption process on...

The lack of sufficient selectivity is the main limitation of chemiluminescence (CL) methods; because the CL reagent is not restricted to a specific analyte. This study investigated the preconcentration and determination of ethion using a flow injection CL (FIA-CL) method using a molecularly imprinted poly high internal phase emulsion (MIP-polyHIPE) adsorbent. Preliminary studies showed that ethion could be determined with high sensitivity in the Ru(bipy)₃ ²⁺ -acidic Ce(IV) CL system. A MIP-polyHIPE adsorbent was synthesized and used for preconcentration to increase the selectivity and sensitivity of the method. The adsorption of ethion on the adsorbent was investigated using density functional theory (DFT) and molecular dynamics (MD), UV-vis and FTIR spectrophotometry and liquid chromatography-tandem mass spectrometry (LC-MS-MS). Response surface methodology (RSM) and central composite design (CCD) were used to find optimized concentrations of variables. The linear dynamic range (LDR) and limit of detection (LOD) for ethion in the FIA-CL method were calculated 1.0 ⨯ 10^-9 to 2.0 ⨯ 10^-7 and 6.0 ⨯ 10^-10  mol L^-1 , respectively. The percentage of relative standard deviation for five repetitive measurements of 5.0 ⨯ 10^-8  mol L^-1 ethion was 4.2%. The proposed method was successfully used to separate and preconcentrate ethion from drinking and surface water sources.