4000 qtrap linear ion

Example 6

Mass spectrometry analyses were conducted using an Applied Biosystems (Foster City, Calif.) 4000 QTRAP linear ion trap quadrupole mass spectrometer to characterize TAG molecular species. The total neutral lipid extract for ESI-MS/MS analysis was prepared as described for seed oil content measurement below but without added internal standard and diluted 1:5000 in water/isopropyl alcohol/methanol (55:35:10 v/v/v) containing 25 mm ammonium formate and 4 μL/L formic acid and directly infused into the mass spectrometer at a rate of 20 μL per minute. Instrument settings were as follows: Source temperature 400° C., ESI needle voltage 5.5 kV (positive mode), desolvation potential (DP) 90, entrance potential (EP) 10, Curtain gas (CUR) 10, and gas 1 (GS1) 50 arbitrary units, gas 2 (GS2) 40 arbitrary units. Neutral loss spectra showing the loss of a specific fatty acid from TAG species were generated by monitoring the loss of 189.1 m/z (for C10:0) and 245.1 m/z (for C14:0). Scans were taken over a mass range of 500-1475 m/z with a cycle time of 3 s. Data was collected for five cycles.

Example 6

Mass spectrometry analyses were conducted using an Applied Biosystems (Foster City, Calif.) 4000 QTRAP linear ion trap quadrupole mass spectrometer to characterize TAG molecular species. The total neutral lipid extract for ESI-MS/MS analysis was prepared as described for seed oil content measurement below but without added internal standard and diluted 1:5000 in water/isopropyl alcohol/methanol (55:35:10 v/v/v) containing 25 mm ammonium formate and 4 μL/L formic acid and directly infused into the mass spectrometer at a rate of 20 μL per minute. Instrument settings were as follows: Source temperature 400° C., ESI needle voltage 5.5 kV (positive mode), desolvation potential (DP) 90, entrance potential (EP) 10, Curtain gas (CUR) 10, and gas 1 (GS1) 50 arbitrary units, gas 2 (GS2) 40 arbitrary units. Neutral loss spectra showing the loss of a specific fatty acid from TAG species were generated by monitoring the loss of 189.1 m/z (for C10:0) and 245.1 m/z (for C14:0). Scans were taken over a mass range of 500-1475 m/z with a cycle time of 3 s. Data was collected for five cycles.