An analytical strategy based on the combination of ultrasound assisted flat membrane liquid phase microextraction and...

In the present work, a new cleanup process entitled ultrasonic assisted flat membrane liquid phase microextraction (UA-FM-LPME) was introduced. The UA-FM-LPME procedure in two phase format was applied for the extraction-preconcentration of malondialdehyde (MDA) as an analyte model from the biological samples after a derivatization reaction. In the designed extraction setup, the simultaneous use of two flat sheet membranes and the application of ultrasonic radiation provided the efficient mass transfer of MDA into the acceptor phase in a short extraction time (2 min). The collected organic phase was then analyzed through Red-Green-Blue (RGB) image analysis and high-performance liquid chromatography coupled with ultraviolet-visible spectroscopy (HPLC-UV/Vis) as detection methods. The key parameters affecting the extraction process were studied and optimized in detail. The effect of the sugaring out on the partition of MDA into the extraction phase was examined for the first time. Under optimal conditions, linearity was observed in the concentration range of 8-1000 ng mL^-1 for HPLC, and 10-1000 ng mL^-1 for RGB analysis, with the coefficient of determination (R²) values higher than 0.9973. The introduced method also offered satisfactory relative standard deviations (RSDs) less than 4.0%. In order to examine the reliability of the technique in complicated matrices, three different biological samples (urine, saliva and blood plasma) were analyzed and the acceptable results in terms of relative recoveries (89.7-102.4%) were obtained. The designed setup in combination with RGB analysis will provide a low-cost alternative technique for rapid determination of MDA in clinical diagnosis or biochemical analysis without the need to complex, time consuming and expensive analytical instruments.