Determination of organophosphate pesticides in sea and surface water with ultrasound-assisted dispersive liquid–liquid micro-extraction coupled to GC-MS/MS analysis

Analysis of organophosphate pesticides in surface water—Comparison of method optimization approaches

“…This result contradicts earlier conclusions, where 1-minute sonication time deemed most effective. 32 Hence, application of OFAT approach as done in the earlier study has led to results not verified by statistically confirmed conclusions of DOE approach.…”

“…At the same time, the Taguchi design covers a large part of the factor space in even distribution. Compared with the earlier OFAT approach (Figure 3, Habedank et al 32 ), more knowledge is gained regarding the overall system and the effect of factor variance throughout.…”

“…The experimental settings assuming optimum levels for the factors were based on the earlier observations. 32 Large differences in response between both experiments indicate a variation of the correct factors. 35 Small differences, however, might be caused by different reasons.…”

“…Starting point for the selection of factors and their variation was the ultrasound assisted DLLME procedure explored earlier with OFAT approach for the analysis of OPP+M amenable by gas chromatography (GC). 32 For the Shainin variable search method, two experiments were conducted. Milli-Q water was spiked to 10 ng L −1 and extracted as described above with varied factor levels.…”

“…Acetone, with a very low logK OW , showed best extraction efficiency for most analytes in preliminary studies. 32 Other techniques such as large volume injection, derivatization, or particularly SPE might lead to better results when considering OPP with logK OW value below 1.…”