Comparative study of HPLC-CAD and ELSD method for determination of glyceryl triricinoleate in castor oil

RAN Wen-hua; PENG Li-fang; LENG Ze-shan; LI Wen-wen; HAO Ji; LIU Jia-jia; XIAO Shu-wen; ZHANG Yang-yang

doi:10.3969/j.issn.1003-3734.2024.12.012

Abstract：Objective:To study and establish an HPLC-CAD method for determination of triglyceride in castor oil,compare it with that of USP by ELSD,and explore the rationality of different detection methods.Methods:For the RP-HPLC-ELSD method,the chromatographic column was C18(250 mm×4.6 mm,5 µm);mobile phase:A methanol,B isopropanol;gradient elution:0～20 min,A 100％～50％;20～23 min,A 50％～0％;23～25 min,A 0％～100％;25～35 min,A 100～100％,1.0 mL·min-1;column temperature 35 ℃;evaporation temperature:40 ℃,N2 speed:1.5 L·min-1.Standard curve method or area normalization method was used for quantitative analysis.For the RP-HPLC-CAD method,the chromatographic column was C18(250 mm×4.6 mm,5 µm);mobile phase:A methanol,B isopropanol;gradient elution:0～20 min,A 100％～50％;20～22 min,A 50％～30％;22～30 min,A 30％;30～32 min,A 30％～100％;32～40 min,A 100％;column temperature 35 ℃;acquisition frequency:10 Hz,filter constant:3.6 s,evaporation temperature:50 ℃.Standard curve method or area normalization method was used for quantitative analysis.Results:The results and method rationality of ELSD and CAD detector were compared and discussed respectively by area normalization method.On the basis of this,the feasibility of the determination of glyceryl triricinoleate in castor oil by standard curve method with glycerol trioleate and glyceryl triricinoleate(triricinoleoyl-glycerol)as reference standard was discussed.Conclusion:An HPLC-CAD calibration curve method was established with glycerol triolein as reference standard.For determination of glyceryl triricinoleate content,the response consistency of CAD detector is higher than that of ELSD,and its area normalization result is closer to the true content.