Self-assembled matrix fabricated by Fe-metal organic frameworks and carboxymethyl cellulose for the determination of small molecules by MALDI-TOF MS

A nanoprobe of laser desorption/ionization-time of flight mass spectrometry (LDI-TOF MS) for the determination of small molecules was developed that is based on the composition of Fe-metal organic frameworks (Fe-MOFs) and carboxymethyl cellulose-Na (CMC-Na). This material is a good adsorbent for small molecules via hydrogen bonding and pi-interactions; we detected three molecules, dopamine, glyphosate, and pyrene. The detection limits for these compounds are 0.01 mg L-1, 1.50 mu g L-1, and 0.01 mu g L-1, respectively; the recoveries are 85-117%, 81-127%, and 89-115%, respectively. The relative standard deviations (similar to 15%) and coefficients of determination of the calibration plot (similar to 0.97) are satisfactory. The applicability of the chip for practical samples is demonstrated by quantifying pyrene in domestic water and polluted lake water; the recoveries are about 90 similar to 117% and 85 similar to 125% (n = 5), respectively; the RSDs are 9.4% and 13.5%, respectively.