Analysis of insect triacylglycerols using liquid chromatography‐atmospheric pressure chemical ionization‐mass spectrometry

Abstract

An HPLC non-aqueous reversed-phase separation system was adapted for analyzing insect triacylglycerols (TAG). The method uses two conventional Nova-Pak C18 columns connected in series, for a total length of 45 cm. The mobile phase gradient is mixed from acetonitrile and 2-propanol, and the flow rate is programmed from 1.0 to 0.7 mL/min. TAG are detected by atmospheric pressure chemical ionizationmass spectrometry. The method ensures efficient separation of isomers and analysis of high-molecularweight TAG with equivalent chain lengths up to 72. The method performance is demonstrated on analysis of TAG isolated from the fat body of the bumblebee Bombus lucorum.

A comparison of HPLC/APCI-MS and MALDI-MS for characterising triacylglycerols in insects: Species-specific composition of lipids in the fat bodies of bumblebee males

“…The TGs were analysed using an HPLC/APCI-MS method optimised previously [9]. The identity of the TG molecular species was determined from the MS spectra based on the molecular adducts and diacylglycerol fragments [3,8,9].…”

“…However, isobaric molecules are not separated and the signal intensities are less reproducible as compared with HPLC/MS. In our previous research, an HPLC/atmospheric pressure chemical ionisation (APCI)-MS method was optimised for analysing insect TGs [8,9]. The method was used for samples isolated from the fat bodies of bumblebee males to support our hypothesis that pool lipids are precursors of male marking pheromones [10].…”

Solid Phase Micro-extraction (SPME) with In Situ Transesterification: An Easy Method for the Detection of Non-volatile Fatty Acid Derivatives on the Insect Cuticle

“…In the pteromalid wasp Lariophagus distinguendus, the TAG fraction of a cuticular extract is an essential component of the female courtship pheromone (Kühbandner et al 2012). Triacylglycerides are chemically characterized by the chain lengths of fatty acids, the number and position of double bonds, and the position of the fatty acids at the glycerol backbone (Cvačka et al 2006c;Kofroňová et al 2009). They occur in large amounts as lipid droplets in the adipocytes of the insect fat body (Arrese and Soulages 2010;Downer and Matthews 1976), which is a storage site for energy and an important metabolic tissue that converts TAGs into pheromone precursors (Arrese and Soulages 2010).…”

Changes in the Composition of Triacylglycerols in the Fat Bodies of Bumblebee Males During Their Lifetime

“…The small differences between the results may be caused by the use of another LC separation method [17]. The resolution of the peaks in this study is better than in the previous paper [8].…”

“…Ammonium acetate dissolved in 2-propanol/ water (1:1) at a 100 mmol/L concentration was added postcolumn via a tee at a flow rate of 10 lL/min. These conditions are based on our previous work [17]. The atmospheric pressure chemical ionization (APCI) source was operated at 400°C, where the heated capillary temperature was 200°C and the corona discharge current was set to 4.5 lA.…”