Determination of Aldehyde and Ketone Compounds Volatilized from Hot Melt of Plastic Wire by High Performance Liquid Chromatography

A self-made gas collection device was used to collect the gas volatilized from hot melt of plastic wire (including ABS, PLA, PCL) used for 3D printing in the fused deposition modeling process, and the content of 15 harmful aldehyde and ketone gases (formaldehyde, acetaldehyde, acetone, propylene aldehyde, butenal, methylacrolein, butanone, butyraldehyde, benzaldehyde, cyclohexanone, glutaldehyde, p-methylbenzaldehyde, o-/m-methylbenzaldehyde, and hexanal) were determined by high performance liquid chromatography (HPLC). In the self-made gas collection device, 10 g of plastic wire were thermally melted at the injection rate of 50 mm·min^-1. Under the action of air filtered by activated carbon, the gas in the collection tube flowed through the ozone-removing tube at a flow rate of 0.5 L·min^-1, and finally derivatized by the 2,4-dinitrophenylhydrazide (DNPH) derivatization column. The column was eluted with 4 mL acetonitrile and 1 mL water, and the eluent was filtered through a 0.45 μm filter after making up with acetonitrile. Then the filtrate was analyzed by HPLC. Synergi MAX RP-C₁₈ reverse-phase chromatographic column was used as the stationary phase, and the mixed solution composed of acetonitrile and water with various volume ratios was used as the mobile phase in gradient elution. The results showed that linearity ranges of the standard curves were same in the range of 0.2-2.0 mg·L^-1, with detection limits in the range of 0.001-0.003 mg·kg^-1. The spiked recovery was made on the PLA wire, giving recoveries in the range of 72.0%-94.0%, and RSDs (n=6) were ranged from 2.2% to 8.6%. The proposed method was used for determination of 21 batches of PLA wires, ABS wires and PCL wires of different brands, finding that the release amounts of formaldehyde and acetaldehyde were relatively larger, the detection frequency of acetone was relatively higher, and the kind and content of aldehydes and ketones produced by PLA wires and ABS wires were larger those of PCL wires.