Simultaneous determination of tetrahydropalmatine and tetrahydroberberine in rat urine using dispersive liquid–liquid microextraction coupled with high‐performance liquid chromatography

Abstract

Dispersive liquid-liquid microextraction (DLLME) coupled with high-performance liquid chromatography (HPLC)-UV detection was applied in rat urine for the extraction and determination of tetrahydropalmatine (THP) and tetrahydroberberine (THB), both active components in Rhizoma corydalis. Various parameters affecting the extraction efficiency, such as the type and volume of extraction and dispersive solvent, pH, etc. were evaluated. Under the optimal conditions (extraction solvent: 37 μL of chloroform, dispersive solvent: 100 μL of methanol, alkaline with 100 μL of 1 mol/L NaOH, and without salt addition), the enrichment factors of THP and THB were more than 30. The extraction recoveries were 69.8-75.8% and 72.7-77.6% for THP and THB in rat urine, respectively. Both THP and THB showed good linearity in the range of 0.025-2.5 μg/mL, and the limit of quantification was 0.025 μg/mL (S/N=10, n=6). The intra-day and inter-day precision of THP and THB were <12.6%. The relative recoveries ranged from 95.5 to 107.4% and 96.8 to 100.9% for THP and THB in rat urine, respectively. The method has been successfully applied to rat urine samples. The results demonstrated that DLLME is a very simple, rapid and efficient method for the extraction and preconcentration of THP and THB from urine samples.

Analysis of Losartan And Carvedilol in Urine And Plasma Samples Using A Dispersive Liquid–Liquid Microextraction Isocratic Hplc–Uv Method

“…with buffer solution, no white sediments were observed in our experiments. These sediments were mentioned in earlier studies [20][21][22][24][25][26][27][28][29][30][31][32][33][34][35][36][37]. With reference to these findings no pretreatment is needed for urine samples.…”

Simultaneous quantification of l‐tetrahydropalmatine and its urine metabolites by ultra high performance liquid chromatography with tandem mass spectrometry

“…A few analytical methods using HPLC–UV or LC–MS/MS have been established for the quantitation of THP enantiomers or l ‐THP in biological samples . However, none of them are suitable for the simultaneous quantification of l ‐THP and its desmethyl metabolites.…”

Recent Advances in Microextraction Techniques of Antipsychotics in Biological Fluids Prior to Liquid Chromatography Analysis

“…After discarding the upper layer solution, the sedimented phase was evaporated to dryness and the dry residue was reconstituted in 50 µL of a acetonitrile-0.1% phosphoric acid solution which was used as a mobile phase and a 20 µL aliquot was injected into a Ultimate XB-C 18 (150 × 4.6 mm i.d., packed with 5 mm particles) column. The extraction recoveries with this technique were higher than 69% and this method was efficiently applied in real urine samples [26].…”