β-Agonists have been abused as the growthpromoting agent in food-producing animals over 20 years. The proof of using illegal drugs in food, which is necessary for a regulatory action, usually requires a high degree of specificity and sensitivity. This paper reported an ultra-high performance liquid chromatography (UHPLC)-ESI/MS/MS method for the confirmation of multi-residues of the 13 β-agonist compounds in milk. A wide range of analytes related to β-agonists (brombuterol, cimaterol, clenbuterol, clenpenterol, clorprenaline, hydroxymethylclenbuterol, isoxsuprine, mabuterol, ractopamine, ritodrine, salbutamol, terbutaline, tulobuterol) with similar chemical structures was investigated in order to demonstrate the applicability of our method. This method consists of a two-step extraction and a MCX SPE cleanup. The final extract was separated by UHPLC within 5 min and then injected in an electrospray ionization mass spectrometry for the determination. Using clenbuterol-D9, salbutamol-D3, and ractopamine-D5 as internal standards, and accomplishing with the matrix matched calibration curves to compensate for the matrix effects, the quantitative data showed good linear response within the concentration ranges studied. The detection limits (CCα) and detection capabilities (CCβ) of the analytes were found in the range of 0.01-0.16 μg/L and 0.03-0.21 μg/L, respectively. Recoveries of the compounds were found from 82.5% to 101% at the spiked level of 0.05-2.5 μg/L, and the relative standard deviation was within the range of 7.17% and 16.4%. Furthermore, an inter-laboratory study among eight laboratories was conducted to further validate the method, and the results were found satisfactory.
A method for determining residues of four botanical insecticides oxymatrine, matrine, rotenone, and azadirachtin in fish by liquid chromatographyelectrospray tandem mass spectrometry (LC-MS/MS) is described. The extraction was achieved using acetonitrile, with the addition of sodium chloride to induce a salting out effect before using n-hexane to defat. Chromatographic separation is achieved on Phenomenex Luna C18 column in the mobile phase composition of acetonitrile and 5 mmol/L ammonium acetate buffer consisting formic acid to provide protons for LC-MS/ MS analysis. Accomplishing with the matrix matched calibration curves to compensate for the matrix effect, the quantitative data showed good linear response within the concentration ranges studied. Detection is carried out using positive-ion electrospray tandem mass spectrometry. Calibrations were linear over a working range of 0.5-50 μg/L for oxymatrine, matrine, rotenone, and 2-200 μg/L for azadirachtin. The average recoveries and the relative standard deviation ranged from 88.6-95.7% and 7.58-10.2%, respectively, in spiked fish samples at concentration levels ranging from 0.5 to 10 μg/kg for oxymatrine, matrine, and rotenone and from 2 to 50 μg/kg for azadirachtin. The limits of detection for oxymatrine, matrine, rotenone, and azadirachtin were 0.29, 0.37, 0.21, and 1.4 μg/kg, respectively. The method is accurate, specific, and sensitive for the analysis of the studied botanical insecticides residues in fish samples.
A method for the determination of methylene blue (MB) and its metabolites (azure A, azure B and azure C) in rat blood by CE-electrospray ionization mass spectrometry (CE-ESI-MS) was developed in this paper. Different analytical parameters were investigated in detail such as pH and concentration of separation buffer, and ESI-MS instrumental parameters. Under the optimum conditions, MB and its metabolites were separated and detected in 27.3 min. LODs (defined as S/N=3) of this method were 0.22, 0.25, 0.10 and 0.30 μg/mL for MB, azure A, azure B and azure C, respectively. To get a satisfactory extraction efficiency of MB and its metabolites in rat blood, different extraction solutions were studied. By using this method, MB and its metabolites (azure A, azure B and azure C) were successfully analyzed in rat blood samples.
Objective: To observe the efficacy of arsenic trioxide(AS2O3) with ATRT for the treatment of patients with acute promyelocytic leukemia(APL). Methods: Seventy-four patients with APL, from 2000 to 2006, were randomly divided into two groups. Thirty-eight patients as treating group received AS2O3+ATRA, another thirty-six patients as control group were treated only AS2O3+ARTA+chemotherapy(DA or HA). Results: The first induced complete remission (CR) was 100%, the three-year relapse rate was 2.6%, the six-year continuous complete remission(CCR) rate was 94.6% for treating group. The rate of CR, the three-year relapse and CCR were 81.3%, 30.7% and 61.5% respectively for control group. The side effects such as myelosuppression, severe infection or septicemia, hepatic, renal and myocardial damage, and the digestive tract side effect were mild compared with that in control group(p<0.01). In treating group, the hyperleukocytosis was not observed, Incidence of the three-year treatment-related mortality (TRM) was 0%, the control group was 16.7%. Conclusion: The combination of AS2O3 and ATRA can obtain a higher CCR, low relapse rate and mild treatment side effects.
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