Comparison of two microextraction methods based on solidification of floating organic droplet for the determination of multiclass analytes in river water samples by liquid chromatography tandem mass spectrometry using Central Composite Design

- A simple, fast, cost effective and environmentally friendly VALLME-SFO-LC-MS/MS method has been developed for multiclass analytes.
- Comparison of VALLME-SFO and DLLME-SFO methods for estimation of multiclass analytes.
- Both method parameters are optimized by statistical Central Composite Design.
- Multiclass analytes including endocrine disrupting chemicals need to be monitored in environmental samples.
- Less amount of organic solvents are used for the analysis of multiclass analytes in river water samples by VALLME-SFO method.

Two low density organic solvents based liquid-liquid microextraction methods, namely Vortex assisted liquid-liquid microextraction based on solidification of floating organic droplet (VALLME-SFO) and Dispersive liquid-liquid microextraction based on solidification of floating organic droplet(DLLME-SFO) have been compared for the determination of multiclass analytes (pesticides, plasticizers, pharmaceuticals and personal care products) in river water samples by using liquid chromatography tandem mass spectrometry (LC-MS/MS). The effect of various experimental parameters on the efficiency of the two methods and their optimum values were studied with the aid of Central Composite Design (CCD) and Response Surface Methodology(RSM). Under optimal conditions, VALLME-SFO was validated in terms of limit of detection, limit of quantification, dynamic linearity range, determination of coefficient, enrichment factor and extraction recovery for which the respective values were (0.011-0.219 ng mL−1), (0.035-0.723 ng mL−1), (0.050-0.500 ng mL−1), (R2 = 0.992-0.999), (40-56), (80-106%). However, when the DLLME-SFO method was validated under optimal conditions, the range of values of limit of detection, limit of quantification, dynamic linearity range, determination of coefficient, enrichment factor and extraction recovery were (0.025-0.377 ng mL−1), (0.083-1.256 ng mL−1), (0.100-1.000 ng mL−1), (R2 = 0.990-0.999), (35-49), (69-98%) respectively. Interday and intraday precisions were calculated as percent relative standard deviation (%RSD) and the values were ≤15% for VALLME-SFO and DLLME-SFO methods. Both methods were successfully applied for determining multiclass analytes in river water samples.