Rxi 624sil ms column

GC-MS analysis relied on an Agilent 8890/7079B GC-MS (Agilent, Santa Clara, CA, USA). The GC injector was equipped with an inert SPME liner (inner diameter 0.75 mm, Supelco, Bellefonte, ON, Canada) and operated in the splitless mode (0.75 min) followed by split mode with a ratio of 1:50. Extracted compounds were separated using a Rxi-624Sil MS column (30 m × 0.32 mm, layer thickness 1.8 μm, Restek, Bellefonte, PA, USA) operated in constant helium flow at 1.4 mL min-1. The column temperature program was as follows: 37 °C for 12 min, followed by 5 °C min-1 up to 150 °C, then 10 °C min⁻¹ up to 290 °C, and finally remaining at 290 °C for 8 min. The untargeted VOC analysis relied on the mass spectrometer working in a SCAN mode with the associated m/z ranging from 20 up to 250. The peak integration was based on extracted m/z ratio chromatograms, and such an approach allowed for a separation of the majority of peaks of interest from their neighbors. The quadrupole rods, ion source, and transfer line were kept at 150 °C, 230 °C, and 280 °C, respectively.
VOC identification was performed using a two-step process. First, the spectrum of a peak was checked against the NIST mass spectral library database. Next, the NIST identification was confirmed by comparing the retention times of peaks of interest with retention times obtained for reference standards prepared as outlined above.

For each refill fluid, 50 µl were dissolved in 0.95 ml of isopropyl alcohol (IPA) (Fisher Scientific, Fair Lawn, NJ). All diluted samples were shipped overnight on ice to Portland State University and analyzed using GC-MS on the day they were received. A 20 µl aliquot of internal standard solution (2000 ng/µl of 1, 2, 3-trichlorobenzene dissolved in IPA) was added to each diluted sample before analysis. Using internal standard-based calibration procedures described elsewhere^{52 (link)}, analyses were performed with an Agilent 5975 C GC-MS system (Santa Clara, CA). A Restek Rxi-624Sil MS column (Bellefonte, PA) was used (30 m long, 0.25 mm id, and 1.4 µm film thickness). A 1.0 µl aliquot of diluted sample was injected into the GC with a 10:1 split. The injector temperature was 235 °C. The GC temperature program for analyses was: 40 °C hold for 2 min; 10 °C/min to 100 °C; then 12 °C/min to 280 °C and hold for 8 min at 280 °C, then 10 °C/min to 230 °C. The MS was operated in electron impact ionization mode at 70 eV in positive ion mode. The ion source temperature was 220 °C and the quadrapole temperature was 150 °C. The scan range was 34 to 400 amu. Each of the 178 target analytes was quantitated using authentic standard material and an internal standard compound normalized multipoint calibration.

The GC-MS analysis was carried out using an Agilent 8890/7079B GC-MS system. The GC injector contained an SPME liner (with an inner diameter of 0.75 mm, supplied by Supelco in Canada) and was maintained at 290 °C and operated in splitless mode for 0.75 min, followed by split mode with a ratio of 1:50. The extracted compounds were separated using an Rxi-624Sil MS column (30 m × 0.32 mm × 1.8 μm, Restek in Bellefonte, PA, USA) under constant helium flow at a rate of 1.4 mL/min. The column temperature program started at 37 °C for 12 min, then ramped up by 5 °C per minute to 150 °C, next ramped up by 10 °C per minute to 290 °C, and finally remained at 290 °C for 8 min. The mass spectrometer operated in the SCAN mode with an associated mass to charge ratio (m/z) range from 20 to 250. The peak integration process relied on extracted m/z ratio chromatograms. By using this approach, the majority of the peaks of interest were effectively separated from neighboring compounds. Throughout the analysis, the quadrupole, ion source, and transfer line were carefully maintained at temperatures of 150 °C, 230 °C, and 280 °C.

GC-MS analysis relied on an Agilent 8890/7079B GC-MS (Agilent, Santa Clara, CA, USA). The GC injector was equipped with an inert SPME liner (inner diameter 0.75 mm, Supelco, Canada) and operated in the splitless mode (0.75 min), followed by split mode with a ratio 1:50. Extracted compounds were separated using an Rxi-624Sil MS column (30 m × 0.32 mm, layer thickness 1.8 μm, Restek, Bellefonte, PA, USA) operated in constant helium flow at 1.4 mL min⁻¹. The column temperature programme was as follows: 37 °C for 12 min, followed by 5 °C min⁻¹ up to 150 °C, then 10 °C min⁻¹ up to 290 °C, and finally remaining at 290 °C for 8 min. The untargeted VOC analysis relied on the mass spectrometer working in a SCAN mode with the associated m/z ranging from 20 up to 250. The peak integration was based on extracted m/z ratio chromatograms, and such an approach allowed for a separation of the majority of peaks of interest from their neighbours. The quadrupole, ion source, and transfer line were kept at 150 °C, 230 °C and 280 °C, respectively.
VOC identification was performed using a two-step process. First, the spectrum of a peak was checked against the NIST mass spectral library database. Next, the NIST identification was confirmed by comparing the retention times of peaks of interest with retention times obtained for reference standards prepared as outlined above.