Abstract:
Objectives To develop a method for the determination of five organophosphate flame retardants, triphenyl phosphate (TPHP), tritotyl phosphate (TCP), tris-(2-chloroethyl) phosphate (TCEP), tris-(2-chloropropyl) phosphate(TCPP) and tris-(1, 3-dichloropropyl) phosphate (TDCPP), in indoor dust using Ultrasound Assisted Extraction-Solid Phase Extraction (UAE-SPE)-High Performance Liquid Chromatography-tandem Mass Spectrometry (HPLC-MS-MS).
Methods Add 3 mL ethyl acetate-acetone (3+2, V+V) into the dust sample (50 mg). After 1 min vortex, 5 min ultrasound, and 5 min centrifugation at 3 500 r/min, and the operation was repeated three times. The supernatant of each time was combined and concentrated to near dryness using nitrogen, reconstituted to 3 mL using n-hexane, enriched and purified through CNWBOND NH2 solid phase extraction column (conditioned with 6 mL ethyl acetate, 6 mL n-hexane), eluted using 3 mL ethyl acetate twice, dried using nitrogen, adjusted to a constant volume using 1 mL acetonitrile-water (1+1, V+V) and filtered with 0.22 μm nylon filter. The five organophosphate flame retardants were eluted and separated in gradient using ACQUITY UPLC®HSS T3 column (150 mm×2.1 mm, 1.8 μm) with 0.1% formic acid solution and acetonitrile solution of 0.1% formic acid as mobile phase, then determined under positive ion mode of Electrospray Ionization (ESI+) and Multiple Reaction Monitoring (MRM) mode.
Results The five organophosphate flame retardants showed a good linearity in the range of (0.5-500) μg/L, and the correlation coefficients were more than 0.999. The limit of detection was in the range of (1.8-36.0) ng/g, and the limit of quantification was in the range of (5.9-120.0) ng/g. The recovery was in the range of 75.0%-116.7% with the relative standard deviations (RSD) of 2.3%-9.7%.
Conclusions The method is fast and reliable, which is suitable for simultaneous determination of five organophosphate flame retardants in indoor dust.