RESUMO
Growing concerns about environmental conditions, public health, and disease diagnostics have led to the rapid development of portable sampling techniques to characterize trace-level volatile organic compounds (VOCs) from various sources. A MEMS-based micropreconcentrator (µPC) is one such approach that drastically reduces the size, weight, and power constraints offering greater sampling flexibility in many applications. However, the adoption of µPCs on a commercial scale is hindered by a lack of thermal desorption units (TDUs) that easily integrate µPCs with gas chromatography (GC) systems equipped with a flame ionization detector (FID) or a mass spectrometer (MS). Here, we report a highly versatile µPC-based, single-stage autosampler-injection unit for traditional, portable, and micro-GCs. The system uses µPCs packaged in 3D-printed swappable cartridges and is based on a highly modular interfacing architecture that allows easy-to-remove, gas-tight fluidic, and detachable electrical connections (FEMI). This study describes the FEMI architecture and demonstrates the FEMI-Autosampler (FEMI-AS) prototype (9.5 cm × 10 cm x 20 cm, ≈500 gms). The system was integrated with GC-FID, and the performance was investigated using synthetic gas samples and ambient air. The results were contrasted with the sorbent tube sampling technique using TD-GC-MS. FEMI-AS could generate sharp injection plugs (≈240 ms) and detect analytes with concentrations <15 ppb within 20 s and <100 ppt within 20 min of sampling time. With more than 30 detected trace-level compounds from ambient air, the demonstrated FEMI-AS, and the FEMI architecture significantly accelerate the adoption of µPCs on a broader scale.