Lc 20at series hplc system

Quantitative analysis was carried out on a Shimadzu LC-20AT Series HPLC system equipped with PL-ELS 1000 evaporative light-scattering detector (Shimadzu, Kyoto, Japan), a quaternary solvent delivery system and a column temperature controller. Chromatographic separation was conducted with the Agilent Infinity Lab Poroshell120 EC-C8 column (2.7 μm, 3.0 mm × 100 mm). The mobile phase was methanol with isocratic elution, and the flow rate was 0.3 mL/min. The column oven temperature was set at 25 °C throughout the analytical process, and the injection volume was 5 µL. The ELSD detector parameters were set as follows: nebulizing gas pressure, 3.4 bar; heating tube temperature, 40 °C; gain value, 11; filter value, 10 s. Shimadzu LC solution software (ver. 1.21SPI) was used for data collection.
For the quantitation of TAGs, the SSDMC method was developed according to a previous study [7 (link)]. The OOO was selected as the internal single standard, and the relative conversion factor (RCF, Fi) was displayed in Table S2. Briefly, the RCF was calculated based on the correlation between the chromatographic response and the concentration of the analyte. Due to the similar structures of these seven compounds, the RCFs of these six analytes compared to OOO were finally confirmed as 1.0.

Mobile phase was a mixture of acetonitrile and 0.02 M phosphate buffer solution pH 2.7 (35 : 65, v : v). The 0.02 M phosphate buffer solution pH 2.7 was prepared by dissolving 2.72 g of potassium dihydrogen phosphate and 3 mL of triethylamine in 900 mL of water, adjusting the pH to 2.7 ± 0.1 by orthophosphoric acid, adding water to make 1000 mL, mixing the solution well, filtering it through 0.45 μm membrane filter, and degassing it by sonication for 15 minutes before using it. The flow rate of mobile phase was maintained at 1.0 mL/min. The analysis was carried out on an Shimadzu LC-20AT series HPLC system equipped with a PDA detector set at 254 nm for recording chromatograms. The chromatographic separation was conducted on a Luna C18 column (250 × 4.6 mm, 5 μm) maintained at 25°C. The injection volume was 50 μl.

The mobile phase was a mixture of methanol and 0.002 M tetrabutylammonium sulfate solution whose composition was set by the gradient program in Table 1. The 0.002 M tetrabutylammonium sulfate solution was prepared by dissolving 1.16 g of tetrabutylammonium sulfate in 1000 mL of water, filtered through a 0.45 µm membrane filter, and degassed by sonication for 15 minutes before used. The flow rate of the mobile phase was maintained at 1.0 mL/min. The analysis was carried out on a Shimadzu LC-20AT series HPLC system equipped with a PDA detector set at 280 nm for recording chromatograms. The chromatographic separation was conducted on a Luna C8 column (250 × 4.6 mm, 5 µm) maintained at 25°C. The injection volume was 20 µl.

The concentrations of 6β-hydroxytestosterone were determined on a Shimadzu LC-20 AT series HPLC system (Shimadzu Corporation, Kyoto, Japan) by injecting 20 μL aliquots of the processed samples onto an Agilent Eclipse Plus C18 column (4.6 × 250 mm, 5 μm), which was heated in a column oven to 30°C. The isocratic mobile phase consisted of (A) acetonitrile and (B) water (containing 0.1% formic acid) (60:40, v:v) and was delivered at 1 ml/min. The UV detector wavelength was set to 247 nm for ATO and 245 nm for 6β-hydroxytestosterone.