Thermo itq1100 gc ion trap ms

Concentrations of remaining ricinoleic acid and accumulating fatty acid products in the medium (i.e., ketone 2 and ester 3) were determined as described previously45 . The reaction medium was mixed with a 3-fold volume of ethyl acetate containing 5 g L⁻¹ palmitic acid as an internal standard. The organic phase was harvested after vigorous vortexing and then subjected to derivatization with N-methyl- N-(trimethylsilyl)trifluoroacetamide (TMS). The TMS derivatives were analyzed using a Thermo Ultra Trace GC system connected to an ion trap mass detector (Thermo ITQ1100 GC-ion Trap MS, Thermo Scientific). The derivatives were separated on a nonpolar capillary column (30-m length, 0.25-μm film thickness, HP-5MS, Agilent). A linear temperature gradient was programmed as follows: 90 °C, 5 °C min⁻¹ to 280 °C. The injection port temperature was 230 °C. Mass spectra were obtained by electron impact ionization at 70 eV. Scan spectra were obtained within the range of 100–600 m/z. Selected ion monitoring (SIM) was used for the detection and fragmentation analysis of the reaction products. Concentration of the reaction substrates and products was determined on a basis of calibration curves, which were determined using commercially available products or products isolated in our lab45 .

The concentrations of the remaining fatty acids and accumulating carboxylic acids in the medium (e.g., 9-hydroxynonanoic acid (6), 1,9-nonanedioic acid (8)) were determined as described previously [13 (link),19 (link),20 (link)]). The reaction medium was mixed with an equal volume of ethyl acetate containing 0.5 g/L methyl palmitate as an internal standard. The organic phase was harvested after vigorous vortexing and subjected to derivatization with N-methyl-N-(trimethylsilyl) trifluoroacetamide. The trimethylsilyl derivatives were analyzed using a Thermo Ultra Trace GC system connected to an ion trap mass detector (Thermo ITQ1100 GC-ion Trap MS, Thermo Scientific, Indianapolis, IN, USA). The derivatives were separated on a nonpolar capillary column (30 m length, 0.25 mm film thickness, HP-5MS, Agilent Technologies, Palo Alto, CA, USA). A linear temperature gradient was programmed as 160 °C, 25 °C/min to 235 °C, and 3 °C/min to 253 °C. The injection port temperature was 230 °C. Mass spectra were obtained within the range of 100–600 m/z. Selected ion monitoring was used for detection and the fragmentation analysis of the reaction products.

The concentrations of remaining carboxylic acids in the medium such as ricinoleic acid, n-heptanoic acid, and ω-hydroxyundec-9-enoic acid were determined as described previously [5 (link)]. The reaction medium was mixed with an equal volume of ethyl acetate containing palmitic acid as an internal standard. The organic phase was harvested after vigorous vortexing and was then subjected to derivatization by adding N-methyl-N-(trimethylsilyl) trifluoroacetamide (TMS). The TMS derivatives were analyzed using a Thermo Ultra Trace GC system connected to an ion trap mass detector (Thermo ITQ1100GC-ion Trap MS, Thermo Scientific, and Indianapolis, IN, USA). The derivatives were separated on a non-polar capillary column (30 m length, 0.25 μm film thickness, HP-5MS, Agilent Technologies, Palo Alto, CA, USA). A linear temperature gradient was programmed as 90°C, 5°C/min to 280°C. The injection port temperature was 230°C. Mass spectra were obtained by electron impact ionization at -70 eV. Scan spectra were obtained within the range of 100–600m/z. Selected ion monitoring (SIM) was used for the detection and fragmentation analysis of the reaction products.