ABSTRACT
A method was developed for the determination of bifenthrin in tea by ultra performance convergence chromatography ( UPC2 ) . The samples were extracted with petroleum ether and cleaned up with Waters Sep-Pak:Carbon NH2 , and then detected by UPC2 . The mobile phase was the mixture of supercritical CO2 and acetonitrile at a flow rate of 1. 5 mL/min. The separation was conducted on a column of ACQUITY UPC2 TM BEH (100 mmí3. 0 mm,1. 7 μm). The UV detector was set at a wavelength of 220 nm. The detection limit was 20 μg/L. The linear range of bifenthrin was 0. 32-10. 30 mg/L. The recoveries ranged from 88. 7% to 98. 2%. The relative standard deviations (RSD) were from 1. 4% to 2. 8%. The result showed that the UPC2 was more efficient, rapid and low-cost than GC-MS. The method can meet the testing requirements of bifenthrin in tea. The efficacy of UPC2 on testing the concentration of bifenthrin in tea was compared with GC-MS based on National Proficiency Testing and the results were satisfactory.
ABSTRACT
A new method was developed for the determination of 11 fat_soluble vitamins ( A, D, E and K) and its derivatives in vitamin tablets by ultra performance convergence chromatography ( UPC2 ) . The mobile phase was the mixture of supercritical CO2 and acetonitrile at a flow rate of 1 mL/min. The separation was carried out on the Waters Acquity UPC2 HSS C18 SB 100 mm × 3. 0 mm i. d. , 1. 8 μm column. The UV detector was set at a wavelength of 284 nm. The limits of detection ( LOD) were 1. 5-2. 0 mg/L, and the calibration linear for VK1 , VK2 , VK3 and VB3 was 3-300 mg/L, linear for VA, VA palmitate, VA formic acid, VE, VE acetate, VD2 and VD3 was 5-300 mg/L, respectively. Its spiked recoveries were 97. 31%-98. 76%, and the relative standard deviations ( RSDs) were 0. 41%-0. 96%. The method is applicable for the determination of fat_soluble vitamins ( A, D, E and K) and Their derivatives in vitamin tablets.