9/13/2023 0 Comments Ultra mas in englishTherefore, its use is recommended, but the isotope abundance ratio will be even lower when the target content is very low in the complex matrix, which may affect isotope matching. Isotope information is very important in HRMS and is an effective supplement to the first-order extracted mass. When the retention time does not meet these requirements, subsequent matching of other conditions such as fragment ions and isotope information is required. If the confirm mode is selected, the retention time is the optional condition for compound confirmation. When the retention time does not meet the requirements, subsequent screening of the fragment ions and isotope abundance ratios will not be performed. As for the selection of the matching mode, if the identify mode is selected, the retention time is a necessary condition for compound confirmation. When the retention time in the self-built database matches the sample collection method, it should be used as one of the screening conditions. The limits of detection (LODs) were 0.02 mg/kg for the 32 drugs in the liquid sample and 0.02 mg/kg for 29 compounds in the solid sample the LODs for chlorothalidone, udenafil, and desmethyl thiosildenafil in the solid sample were 0.04 mg/kg. Therefore, solid and liquid negative matrix extracts were used to prepare a series of mixed standard solutions in order to reduce the ME values. Thiohomo sildenafil, desmethyl thiosildenafil, and chlorpretadalafil exhibited strong matrix inhibitory effects in the solid matrix. The matrix effect (ME) values of the 32 compounds ranged from 0.61 to 0.95 in the solid matrix and from 0.73 to 1.09 in the liquid matrix. The recoveries were 60.4% to 109.3% in the liquid matrix, with the RSDs ranging from 0.77% to 8.2%. Except dapoxetine, hydroxythiohomo sildenafil, thiohomo sildenafil, thiosildenafil, desmethyl thiosildenafil, the recoveries ranged from 50.5% to 84.5% in the solid matrix, with the relative standard deviations (RSDs) ranging from 1.2% to 13%. All the compounds showed an excellent linear relationship, with correlation coefficients ( r 2) above 0.99. The measured and theoretical values of the exact mass of the 32 compounds in the two matrix-spiked solutions were within an error of 5×10 -6, and the MS 2 fragment ions were within an error of 1×10 -5. All the 32 compounds could be well separated within 17 min. Positive and negative ion full scanning/data-dependent secondary scanning mode was used to collect the 32 target compounds within 17 min, and TraceFinder software was used to screen the fragment ions. The analytes were separated on a Hypersil gold vanquish column (100 mm×2.1 mm, 1.9 μm) by gradient elution with acetonitrile/water (containing 0.1%(v/v) formic acid) as the mobile phase at a flow rate of 0.3 mL/min. The experimental conditions such as the type of extraction solvent and chromatographic column temperature were explored in detail. An HRMS database was established by comparing the response intensity of each compound in the positive and negative modes. This research focused on the derivatives of illegally added drugs. In addition, the key points of the database establishment and application are summarized. A novel method based on ultra-high performance liquid chromatography-orbitrap high-resolution mass spectrometry (UHPLC-Orbitrap HRMS) was developed for the rapid screening and confirmation of 32 illegally added drugs in slimming and anti-impotence health foods.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |