Rapid liquid-phase microextraction of analytes from complex samples on superwetting porous silicon for onsite SALDI-MS analysis.

To simplify the pretreatment process of complex samples is a key step for rapid detection. Herein, we report a single-step method to rapidly extract analytes with liquid-phase microextraction (LPME) from complex samples on a superwetting porous silicon (PSi) for onsite detection with surface-assisted laser desorption/ionization mass spectrometry (SALDI-MS). The operation time is less than 3 min with this simple method. The limit of detection (LOD) of malachite green in lake water is lowered to 10-13 M, that of verapamil and methadone in whole blood is down to 10-11 M and 10-13 M, in urine is 10-13 M and 10-14 M, respectively; and the ranges of quantification is up to 8 or 9 orders of magnitude with high precision (coefficients of determination (R2) > 0.98) for the complex samples. This method could provide an approach to directly extract target compounds from complex samples on substrate for SALDI-MS analysis.