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A novel method for separating and enriching trace phthalate esters (PAEs) in river water by solvent sublation and their determination by high-performance liquid chromatography (HPLC) has been developed. The optimal conditions of the solvent sublation were obtained, that is n-hexane as the sublation solvent, pH 7 of the solution, a nitrogen flow rate of 70 mL min-1 and sublation time of 70 min. The floated product under the optimal conditions was determined by HPLC. In the process of HPLC analysis, an Eclipse XDB-C18 chromatographic column was used, and mobile phase consisted of acetonitrile and water using gradient elution, and the flow rate was 1.00 mL min-1. The proposed method was applied to determine eight PAEs in the river water from Fangshan District, Beijing; the recoveries ranged from 76.9 to 120.4%, RSD values from 2.63 to 9.71%, and limit of detection values ranged from 0.001 (for diethyl phthalate and butyl benzyl phthalate) to 0.225 µg L-1 (for dimethyl phthalate and dicyclohexyl phthalate). [ABSTRACT FROM AUTHOR]

A novel method is developed for separating and enriching pyrethroid pesticides from vegetables by solvent sublation, and determination of the pyrethroids is performed by high-performance liquid chromatography (HPLC). The effects of organic solvent, pH of the solution, nitrogen flow rate, and sublation time on the sublation efficiency of pyrethroids are investigated in detail, and the optimal conditions of the solvent sublation are selected. The floated product of vegetables in the optimal conditions is determined by HPLC. The limit of detection values range from 1.4 µg/kg (for bifenthrin) to 4.2 µg/kg (for fenpropathin). The recoveries of spiked vegetable samples are from 85.7% to 110.4%, and relative standard deviation values are from 1.70% to 6.19%. The results are satisfactory. [ABSTRACT FROM AUTHOR]

Solvent sublation was studied as a method of separating and pre-concentrating traces of Zn(II), Cd(II) and Cu(II) as diphenylthiocarbazone (dithizone) complexes for their determination. The experimental conditions, such as pH of solution, amount of dithizone as ligand, stirring time, gas flow rate and flotation time, were optimized. Different non-ionic surfactants and types of organic solvents were optimized for efficient sublation. The analyte ions in a 350?mL sample were complexed as metal-dithizone complexes by adding 10?mL of 0.084% dithizone, 0.5?mL of 0.1% nonylphenol polyoxyethylene ether (NP) and 10?mL of pH 4.3 potassium hydrogen phthalate-sodium hydroxide buffer solution. The solution was stirred with a mechanical stirrer for 30?min. It was transferred to a flotation cell, and the complexes were floated by bubbling air and extracted into 10?mL of methylisobutyl ketone (MIBK) on the surface of the aqueous solution. The analytes in the organic phase were determined by flame atomic absorption spectrometry (F-AAS) for Zn(II) and by graphite furnace atomic absorption spectrometry (GF-AAS) for Cd(II) and Cu(II). The proposed method was applied to determine Zn(II), Cd(II) and Cu(II) in real water samples; the enrichment factor was more than 37, the RSD was less than 4.26%, recoveries ranged from 92.7 to 107.3%, and the detection limits were 1.0?µg?L-1 for Zn(II), 0.006?µg?L-1 for Cd(II) and 0.06?µg?L-1 for Cu(II). The results obtained were satisfactory. [ABSTRACT FROM AUTHOR]

The complexation of baicalin with ferrous (II) and its characterization are reported. A orthogonal test was used to optimize the conditions of the complexation of baicalin and ferrous (II). The composition and structure of baicalin-ferrous (II) complex were characterized by elementary analysis, TG-DTA methods, and IR- and UV-spectral analysis. Coordination bonding is dependent on the nature of the baicalin and ferrous (II) ion, their ratio, the pH of the solution, etc. The strongest complex forms between baicalin and ferrous (II) (2:1 ratio). [ABSTRACT FROM AUTHOR]

In this work, high-purity baicalein was prepared. In the process of preparation, baicalin was obtained from Scutellaria baicalensis Georgi by alkali-solution and acid-isolation methods, and then high-purity baicalein was obtained by hydrolysis of baicalin and column chromatography purification. The purified product was identified by FTIR, UV, 1H NMR and HPLC, and the purity was found to be 99.35%. [ABSTRACT FROM AUTHOR]

In the midst of the opioid crisis in the US, efforts to mitigate overdose risks have become paramount, leading some states to introduce mandates for coprescribing the life-saving overdose reversal drug naloxone. These mandates were designed to specifically address people receiving opioid analgesics who had an elevated risk for overdose. This included people receiving high opioid dosages, those concurrently using benzodiazepines, or those with a history of substance use disorder or overdose. Using a nationally representative, multipayer cohort of patients receiving prescription opioids, we investigated how naloxone codispensing rates changed at the state level from 2016 to 2021 among patients with an elevated risk for overdose. Then we used controlled interrupted time series analyses to assess mandates' longitudinal impact on naloxone codispensing in ten states that implemented mandates. We observed an immediate and significant increase in the naloxone codispensing rates in eight states after the implementation of mandates. Nevertheless, in five of these states, the codispensing rates exhibited a subsequent downward trend after the initial increase. State mandates show potential for improving naloxone codispensing; however, mandates alone might not be adequate for sustained change. Further research is needed to identify strategies complementing and enhancing the impact of mandates in combating the overdose crisis.