Development and validation of a rapid method to quantify neutral lipids by NP-HPLC-charged aerosol detector

The study of triglycerides gastrointestinal fate is of main importance due to their nutritional and health implications. In this matter, there is a need for a specific, reliable and fast method to quantify lipid digestion products. The HPLC-CAD method developed in this work proposes a fast manner to simultaneously quantify triolein, sn1,2/2,3-diolein, sn-1,3-diolein, sn-2-monoolein, sn-1/3-monoolein and oleic acid. First, the HPLC separation was optimized by exploiting the elution gradient program and for quantification, optimal CAD detector settings were selected: evaporator temperature of 35 degrees C and power function value equal to 1.6. Second, the optimized chromatographic method was validated for all analytes. Limits of detection and quantification ranged between 0.8 and 7.3 ng, and between 2.7 and 24.4 ng, respectively. A wide linear range was determined for the six analytes and their calibration curves presented an excellent linear fit (R2 = 0.999, y-intercept = 0.5-2.6%, and RSD <= 8.4 %). Accuracy varied between 93 and 114 %, while precision values ranged between 0.4 and 2.3 %. Finally, the developed HPLC-CAD method was successfully applied to study the digestive fate of an emulsion during in vitro digestion. The proposed HPLC-CAD method constitutes an interesting analytical platform to gain insight into the molecular mechanism of lipid digestion.

Automated summary

The developed HPLC-CAD method allows for simultaneous quantification of multiple lipid digestion products, providing an interesting analytical platform for studying the molecular mechanism of lipid digestion.