7890gc 5975 msd gas chromatograph mass spectrometer

The analysis of DEHP concentrations in soil after incubation for 28 days was carried out according to Ma et al [19 ]. DEHP in 10 g of soil was extracted with a total volume of 70 mL acetone:hexane (1:1 v/v) three times in a water bath at 25°C and reduced in the flask by rotary evaporation to 1–2 mL (350 mbar, 40°C water bath, 80 rpm) after centrifugation at 1 500 rpm. Column chromatography purification was performed in a glass column (1 × 26 cm) with Na₂SO₄, neutral Al₂O₃ and neutral silica gel (from bottom to top) with acetone:hexane (1:4 v/v) before collection and reduction to < 1 mL by rotary evaporation as described above.
Analysis was performed with an Agilent 7890GC-5975 MSD gas chromatograph-mass spectrometer. During analysis, whole procedure blanks, soil matrix blanks, spiked soil matrix and parallel samples were all employed together with analysis of the certified reference material to ensure quality control.

The analysis of DnBP or DEHP concentrations in soil after incubation for 30 days was carried out following the approach of Ma et al [40 ]. Target PAEs in 10 g of soil were extracted with a total volume of 70 mL acetone:hexane (1:1, v/v) three times in a water bath at 25°C and reduced in the flask by rotary evaporation to 1 ± 2 mL (350 mbar, 40°C water bath, 80 rpm) after centrifugation at about 252 ×g. Column chromatography purification was conducted in a glass column (1 × 26 cm) with 2g of Na₂SO₄, 6 g of neutral Al₂O₃ and 12 g of neutral silica gel (from bottom to top) with 55 ml of acetone:hexane (1:4, v/v) before collection and reduction to < 1 mL by rotary evaporation as described above.
Analysis was conducted with a 7890GC-5975 MSD gas chromatograph-mass spectrometer (Agilent, Santa Clara, CA). During analysis, whole procedure blanks, soil matrix blanks, spiked soil matrix and parallel samples were all employed together with analysis of a CRM sample to ensure quality control. The recovery rates of DnBP and DEHP extraction ranged from 80 to 110% and the recovery of the analysis method was 90.5% ± 4.1% which meets the requirements of trace PAE analysis in environmental materials.

VOCs were collected using a SAAB-57318 (75 μm CAR/PDMS) SPME. A new SPME fiber was preconditioned with helium at 270 °C for 2 h before use. Extractions were performed in 15 mL Supelco SPME vials filled with 7 mL bacterial fermentation (OD = 1.0–1.2 A) containing a stirring rod. A thermostatic magnetic stirrer was placed on top of the vials. The SPME needle pierced the septum, and the fiber was exposed to the headspace of the vial for 120 min at 60 °C with constant magnetic stirring. Analysis of microbial VOCs was conducted via GC-MS.
VOCs produced via the representative isolates were detected using a 7890 GC/5975 MSD gas chromatograph/mass spectrometer (Agilent, Santa Clara, CA, USA) [23 (link),24 (link),25 (link)]. Identification of compounds was carried out via comparison of retention times and mass spectral data. Relative content was determined from the standard chart (spectrogram database NIST111L). Each data is the mean of three replicates.