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Abstract

Residues of the fungicides difenoconazole, propiconazole, cyflufenamid, and mandipropamid were determined in tomato fruit using acetonitrile for extraction and LC-MS/MS for quantification. Validation criteria include linearity range, the limit of detection (LOD) and limit of quantitation (LOQ), accuracy in terms of precision and trueness, and matrix effect were studied. The recovery rates of the method ranged from 91.8 to 106.3%. The precision of the method in terms of repeatability at one day (RSDr) and between three days (RSDR) ranged from 2.8 to 6.4% and from 4.3 to 7.6%, respectively, with good trueness from 92.2 to 96.4%. Matrix effects (suppression effects) ranged from 3.8% to 11.1%. The validated method was used to evaluate the dissipation kinetics of three different premix formulations: 30% EC (15% difenoconazole + 15% propiconazole), 14% DC (12.5% difenoconazole + 1.5% cyflufenamid), and 50% SC (25% difenoconazole + 25% mandipropamid) used on field tomatoes in Egypt. A first-order kinetic equation best describes residue dissipation. The calculated half-lives of difenoconazole, propiconazole, cyflufenamid, and mandipropamid were 2.01–2.27, 1.89, 1.97, and 1.71 days, respectively. The dissipation rate of difenoconazole did not differ significantly in the three premix formulations. Mandipropamid also dissipated faster compared to the other fungicides tested. The chronic dietary risk assessment results showed a minimal risk to adult Egyptian consumers. Waiting periods were advised for the safe consumption of tomatoes treated with the tested premix formulations.

Open access

Summary

Reversed phase high-performance liquid chromatography (RP-HPLC) and thin-layer chromatography (TLC)-spectrodensitometric methods have been developed and validated for the separation and quantitation of two binary mixtures: Ofloxacin (OFX) and dexamethasone (DXM) in eye preparation; ciprofloxacin hydrochloride (CIP) and hydrocortisone (HYD) in ear preparation. The linearity ranges of RP-HPLC methods were found to be (2.5–45 μg mL−1) for OFX, (2.5–50 μg mL−1) for DXM and (1–8 μg mL−1) for both CIP and HYD. The percentage recoveries/relative standard deviation (RSD) were found to be 100.36/1.38, 100.13/1.49, 99.98/0.61 and 100.28/1.27, respectively. The linearity ranges of TLC-spectrodensitometric methods were found to be (0.5–2 μg band−1), (0.5–3.5 μg band−1), (0.2–1.6 μg band−1), and (0.6–2 μg band−1) for OFX, DXM, CIP, and HYD, respectively. The percentage recoveries/RSD were found to be 99.98/1.06, 99.93/1.18, 99.74/1.27, and 99.94/1.54, respectively. A comparative study was conducted to show the advantages of the proposed methods which showed that the TLC-spectrodensitometric methods were simpler, more sensitive, and economic, while RP-HPLC methods were more precise and robust. The methods were validated in compliance with the ICH guidelines and were successfully applied for determination of the selected drugs in their laboratory-prepared mixtures and commercial dosage forms.

Open access

This study investigated the diagnostic value of soluble urokinase plasminogen activator receptor (suPAR) and serum lactate in elderly patients with sepsis and evaluated their capacity to predict mortality and their correlation to Sequential Organ Failure Assessment (SOFA) score. The study included 80 participants, divided into two groups: 40 cases (mean age, 68.9 ± 5.9) admitted to the intensive care unit and 40 healthy controls (mean age, 67.1 ± 6.2). Elderly patients with sepsis had significantly higher levels of serum suPAR and lactic acid compared to healthy controls. Receiver operating characteristic (ROC) curve analysis showed that suPAR (cutoff value, ≥4.37 ng/ml) has higher area under the curve (AUC) than lactic acid (cutoff value, ≥1.95 mmol/l) for diagnosing sepsis. Serum lactate has superior prognostic value compared to suPAR with AUC of 0.82 (cutoff value, 2.2 mmol/l) and 0.72 (cutoff value, 6.3 ng/ml), respectively. The diagnostic power of combined usage of suPAR and lactate serum concentrations showed AUC of 0.988 (95% confidence interval 0.934 to 1.0). The combination of both biomarkers either together or with SOFA score may serve as a useful guide to patients who need more intensive resuscitation.

Open access

Abstract

In this study, the mineralogical content of Abu Rusheid mylonite sample was investigated and revealed that the sample is essentially composed of quartz and feldspar (72.14% mass), muscovite (16.6% mass), and contains heavy economic polymetallic minerals of about 2.65% by mass. By studying the differences in the physical properties of this mineral content, a proposed flow sheet was set up to explain the successive physical upgrading steps for concentrating and separating the valuable minerals content and getting rid of the associated gangue minerals. Industrial, economic and strategic polymetallic minerals were identified at Abu Rusheid mylonite sample, including cassiterite, titanite, brass, kasolite, monazite, and uranothorite. A group of sulfide minerals also existed as pyrite, arsenopyrite, galena, and molybdenite in addition to the presence of fluorite and iron oxides bearing rare earth elements (REEs) and base metals. Using dry high intensity magnetic separation followed by wet gravity separation and flotation, three concentrates were obtained; heavy paramagnetic concentrate (monazite, columbite, brass, and jarosite), heavy diamagnetic concentrate (zircon, kasolite, uranothorite, cassiterite, and sulphide minerals) and muscovite concentrate for industrial uses. Physical processing of Abu Rusheid mylonite sample was carried out to produce high grade mineral concentrate used as a raw material for chemical treatment to extract economic elements that necessary for several industries.

Open access