RESUMO
In Shijiazhuang City, ozone ï¼O3ï¼ pollution occurs frequently in June every year. In June 2023, the average O3 8 h concentration ï¼O3-8hï¼ pollution exceeded 80% of the days in the month, and O3 was the primary pollutant, accounting for 100%. For an O3 heavy pollution process from June 11 to 18, the air quality model WRF-CMAQ was used for simulation, and the average error data MFB and MFE were -10.47% and 17.96%, respectively, which was within the ideal error range. The CMAQ process analysis module was used to simulate the physical and chemical processes in Shijiazhuang City, and the dry deposition ï¼DDEPï¼ contribution concentration was -23.88 µg·m-3, which was the main process of O3 consumption, whereas the transport process ï¼TRANï¼ was the main source of O3, among which the contribution was more significant in vertical transport ï¼VTRAï¼. At the same time, the source analysis module ï¼ISAMï¼ was used to analyze the O3 contribution of local and surrounding areas in Shijiazhuang City. The results showed that the contribution rate of local industry sources in Shijiazhuang City was as followsï¼ traffic source ï¼12.54%ï¼ > industrial source ï¼6.94%ï¼ > residential source ï¼6.56%ï¼ > power source ï¼4.75%ï¼. The long-distance transmission source ï¼BCONï¼ continued to be in the first place with a high contribution rate of 63.31%. In the heavy pollution period under stable weather, the contribution concentration of BCON in the D02 layer of the nested domain to Shijiazhuang City was lower than the sum of the marked area. Among the surrounding cities, Baoding City had the highest contribution rate under stable weather, accounting for 26.21%. In the late period, the contribution concentration of Xingtai City increased rapidly under the action of high-value southwest wind. To effectively reduce O3 pollution, it is necessary to reduce emissions in the city and to control the upwind cities in advance, and the implementation of inter-regional joint prevention and control is the key.
RESUMO
Diosgenin, a steroidal sapogenin, has attracted attention worldwide owing to its pharmacological properties, including antitumor, cardiovascular protective, hypolipidemic, and anti-inflammatory effects. The current diosgenin analysis methods have the disadvantages of long analysis time and low sensitivity. The aim of the present study was to establish an efficient, sensitive ultrahigh-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) approach for pharmacokinetic analysis of diosgenin amorphous solid dispersion (ASD) using tanshinone IIA as an internal standard (IS). Male Sprague-Dawley rats were orally administered diosgenin ASD, and orbital blood samples were collected for analysis. Protein precipitation was performed with methanol-acetonitrile (50 : 50, v/v), and the analytes were separated under isocratic elution by applying acetonitrile and 0.03% formic acid aqueous solution at a ratio of 80 : 20 as the mobile phase. MS with positive electron spray ionization in multiple reaction monitoring modes was applied to determine diosgenin and IS with m/z 415.2â¶271.2 and m/z 295.2â¶277.1, respectively. This approach showed a low limit of quantification of 0.5 ng/ml for diosgenin and could detect this molecule at a concentration range of 0.5 to 1,500 ng/ml (r = 0.99725). The approach was found to have intra- and inter-day precision values ranging from 1.42% to 6.91% and from 1.25% to 3.68%, respectively. Additionally, the method showed an accuracy of -6.54 to 4.71%. The recoveries of diosgenin and tanshinone IIA were 85.81-100.27% and 98.29%, respectively, with negligible matrix effects. Diosgenin and IS were stable under multiple storage conditions. Pharmacokinetic analysis showed that the C max and AUC0â¶t of diosgenin ASD were significantly higher than those of the bulk drug. A sensitive, simple, UPLC-MS/MS analysis approach was established and used for the pharmacokinetic analysis of diosgenin ASD in rats after oral administration.