Development and validation of an ultra-high performance supercritical fluid chromatography-photodiode array detection-mass spectrometry method for the simultaneous determination of 12 compounds in Piper longum L.

An ultra-high performance supercritical fluid chromatography-photodiode array detection-mass spectrometry (UHPSFC-MS) method for quality control of Piper longum L. has been developed and optimized. Hexane/isopropanol (70/30, v/v) was determined as the final injection solvent and methanol as the organic modifier. A design-of-experimental (DoE) approach was used to optimize column temperature, back-pressure and the gradient slope simultaneously using Trefoil CEL1 column. The back-pressure, temperature, flow rate were set at 130 bar, 32.5 °C and 1.0 mL/min, respectively. Positive electrospray ionization was used in the single ion monitoring mode. The 12 analytes were analyzed within 8 min using the optimized conditions. The linearities of the standard calibrations were satisfactory with coefficients of determination (R2) > 0.995. The recovery measured varied from 96.34% to 105.00% with relative standard deviation (RSD) ≤ 4.68%. The method was sensitive, reliable and effective, and successfully applied to simultaneous determination of 12 compounds in 28 batches of P. longum.