Agilent 5973 network mass selective detector

Analytical gas chromatography was performed at a HP 6890 Series GC (Agilent, stationary phase: HP-5 column, poly-dimethyl/diphenyl-siloxane, 95/5) with a flame ionization detector using the following temperature profile: 60 °C (hold 3 min), then 15 °C/min to 250 °C (hold 5 min). The amounts of mesitylene and sodorifen were determined by peak area integration. Mass spectrometric analysis was performed with electron impact ionization (EI, 70 eV) on a Agilent HP 6890 Series GC–MS (Agilent, stationary phase: HP-5MS column, poly-dimethylsiloxane, 30 m, mass detection: Agilent 5973 Network Mass Selective Detector) using the same temperature profile as for analytical GC. NMR spectra of sodorifen and the E. coli-derived indole were directly recorded from head-space samples on a Bruker AVHD500 and a Bruker AV500-cryo spectrometer in CDCl₃ (see Additional file 1: Figure S6).

Total fatty acids of lipid extracts were analyzed using GC-MS upon transmethylation [13 (link),25 (link)] by derivatizing aliquots of 30 μg of each lipid extract dissolved in 1 mL of n-hexane containing a C19:0 internal standard (0.75 μg mL⁻¹, CAS number 1731-94-8, Merck, Darmstadt, Germany). The resulting fatty acid methyl esters (FAMEs) were dissolved in 50 µL n-hexane, and 2 μL of this solution was injected into an Agilent Technologies 6890 N Network Chromatograph (Santa Clara, CA, USA) equipped with a DB-FFAP column with a length of 30 m, an internal diameter of 0.32 mm and a film thickness of 0.25 μm (J&W Scientific, Folsom, CA, USA) connected to an Agilent 5973 Network Mass Selective Detector. Operating settings used have been described previously [13 (link)]. Fatty acid identification was performed by comparing the retention times and mass spectra obtained to those of the commercial FAME standards in the Supelco 37 Component FAME Mix (ref. 47885-U, Sigma-Aldrich, Darmstadt, Germany). The average chain length (ACL), double bond index (DBI), peroxidizability index (PI), and content of monounsaturated fatty acids (MUFA), polyunsaturated fatty acids (PUFA), polyunsaturated fatty acids n-3 (PUFA n-3), and polyunsaturated fatty acids n-6 (PUFA n-6) were determined as previously described [27 (link)].

The monosaccharide composition of the EPSs produced by R. babjevae was analyzed using GC-MS. Briefly, the preliminary hydrolysis was carried out by dissolving 10 mg of the EPSs in 1 mL of 2 M trifluoroacetic acid. This mixture was vortexed for 10 sec and incubated in a dry water bath at 120°C for 90 min. The solution was evaporated under a stream of nitrogen. Trimethylsilylation derivatization was performed according to Pierre et al.^{15 (link)} l-Rha, l-Fuc, l-Ara, d-Xyl, d-Man, d-Gal, d-Glc, d-GlcA, d-GalA, d-GlcN and d-GalN, which were used, are standard. According to Benaoun et al,^{16 (link)} analysis was carried out by GC-MS-EI using Agilent 6890 Series GC System coupled to an Agilent 5973 Network Mass Selective Detector.

PEO product purchased from Guangdong Ruisheng Technology Co., Ltd (Guangzhou, China), which contained 65% silicon dioxide and 30% plant essential oils. The composition of plant essential oil was analysis by GC/MS (Agilent 5973 Network Mass Selective Detector, Agilent Technologies,USA), the relative content of the active components were 78.3% Cinnamic dehyde (RT = 33.6), 4% Isophorone (RT = 22.9), and eugenol (2.7%) (Fig. 5).

Fresh plant materials (0.5 g) were collected and ground with liquid nitrogen and extracted with 2.5 ml pentane containing 2 ng/μl nonyl acetate in a shaker at 28°C for 1 h. The extractions were analyzed by gas chromatography–mass spectrometry (GC–MS; Agilent 6890 Series GC System coupled to an Agilent 5973 Network Mass Selective Detector), with the temperature program: initial temperature of 40°C (5 min hold), increase to 160°C at 10°C/min, and ramp to 280°C at 30°C/min (5 min hold). Products were identified by comparison with authentic standards and NIST (National Institute of Standards and Technology) and Wiley libraries.

Worms exposed to each dose of BPA or BPS from L1 stage to adulthood were collected and washed 10 times for 10 minutes each with M9 buffer. To extract Bisphenols, 100 mg of worms were homogenized in HPLC-grade water and centrifuged at 3,000 g for 5 minutes. The lysate was purified on a methanol-water pre-conditioned Strata-X high performance polymeric reversed phase cartridge (Phenomenex) and dried under a 1 L/min stream of nitrogen at 35°C. The dried residue was redissolved and derivatized at 75°C for 30 minutes with 100 μl N,O-bistrifluoroacetamide (BSTFA) containing 1% trimethylsilyl chloride (Cerilliant) for silylation. The final derivative was dried under a 1 L/min stream of nitrogen and reconstituted with 50 μl acetonitrile. GC-MS analysis was performed on an Agilent 6890N gas chromatograph coupled with an Agilent 5973 network mass selective detector. Silylated 4-cumylphenol was directly derivatized from 4-cumylphenol (Sigma Aldrich) and used as internal standard. Silylated BPA and BPS (Sigma Aldrich) were used as external standard. 3 μl of final derived sample was injected into the GC column in splitless mode at 280°C. The quantifiable limit of detection was 0.001ug/g of worm tissue for silylated-BPA and 0.1ug/g of worm tissue for silylated BPS.

Extracted lipids were transmethylated to FAME as previously described [15] and TAG separation was accomplished by thin layer chromatography. FAME was analyzed using an Agilent 6890 Series Gas Chromatography System with an Agilent 5973 Network Mass Selective Detector (Agilent Technologies, Delaware, USA). Chromatography was carried out using a 200 m×250 µm×0.25 µm Varian GC capillary column (Varian Inc., California, USA) with the inlet held at 270°C while 1 µl of the sample was injected using helium as the carrier gas. The oven temperature was programmed for 130°C (10 min) to 160°C (7 min); 160°C to 190°C (7 min), from 190°C to 220°C (22 min) and from 220°C to 250°C (17 min) at a rate of 10°C min⁻¹ for each step. The total analysis time was 75 minutes using 70 eV electron impact ionization and data was evaluated with total ion count.