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ABSTRACT. Charge transfer complexes of some antifungal drugs fluconazole (FLU), sertaconazole nitrate (SER) and miconazole nitrate (MCO) as electron donor with the σ-acceptor iodine (I2) and 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ), p-chloranilic acid (p-CLA) and 7,7,8, as π-acceptors in acetonitrile were investigated. The formation of the colored charge-transfer complexes were utilized in the development of simple, rapid and accurate spectrophotometric methods for the analysis of the cited drugs in pure forms and pharmaceutical formulations at 365 nm for MCO and SER using I2 method, at 460 nm for FLU and SER using DDQ method, at 535 and 530 nm for FLU and SER, respectively, using p-CLA method and at 842 nm for MCO and SER using TCNQ method. The optimum experimental conditions have been studied carefully and optimized. Beer's law was obeyed over the concentration ranges of 2.0-28, 10-240 and 2.0-160 µg mL −1 for MCO, FLU and SER, respectively, with good correlation coefficients (0.9996-0.9999). Molar absorpitivity, Sandell sensitivity, relative standard deviation, limit of detection and quantification were calculated. The obtained data refer to high accuracy and precision of the proposed method. The obtained results were confirmed by inter and intra-day accuracy and precision with percent recovery of 99.1-100%, 99.3-101% and 99.1-101% for MCO, FLU and SER, respectively. These data were compared with those obtained using official methods for the determination of the cited drugs. The proposed methods were applied successfully for simultaneous determination of the cited drugs in their pharmaceutical formulations with good accuracy and precision and without interferences from common additives.

Simple, rapid, cost-effective, sensitive and extractive spectrophotometric methods were developed for the determination of two antifungal drugs (i.e., sertaconazole nitrate (SER) and miconazole nitrate (MCO)) in pure and dosage forms. The methods are based on the formation of ion-pair complexes between the drugs and acid dyes (i.e., bromocresol purple (BCP), bromophenol blue (BPB) and methyl orange (MO)) in acidic buffer solutions. The formed complexes were extracted with chloroform and measured at 410, 416 and 427 nm for SER and at 408, 415 and 426 nm for MCO using BCP, BPB and MO, respectively. The analytical parameters and their effects on the reported systems were investigated. Beer's law was obeyed in the 1.0-20 and 1.0-24 g mL −1 ranges for SER and MCO, respectively. The composition of the ion pairs was determined to be 1:1. The molar absorptivity, Sandell sensitivity, limits of detection and limits of quantification were calculated. Other method validation parameters, such as precision, accuracy, robustness, ruggedness and selectivity, were satisfactory. The proposed methods have been successfully applied for the analysis of the studied drugs in their pure and dosage forms. Statistical comparison of the results with the reference methods indicated excellent agreement and no significant difference in accuracy and precision.

A new, eco-friendly, and rapid micelle-mediated preconcentration technique was described for trace mercury in water, food and hair samples perior to its spectrophotometric determination. The developed method depended on cloud point extraction supported with ionic liquid (IL-CPE) for extraction of mercury utilizing a nonionic surfactant (Triton X-114) and 1-hexadecyl-3methylimidazolium chloride (C16MeImCl) ionic liquid, as an extracting phase in the presence of 5-benzyl-4-[4methoxybenzylideneamino)-4H-1,2,4-triazole-3-thiol (BMBATT) as a new chelating agent at pH 7.0. The influence of varous analytical variables on improving the extraction performance was tested. In the range of 2.0-600 µg L −1 , the calibration curve was linear with correlation coefficient of 0.9997. The detection limit and preconcentration factor were 0.4 µg L −1 and 100, respectively. The reliability and precision of the developed IL-CPE system as the relative standard deviation (RSD %) of 100 and 400 µg L −1 mercury were in the range 1.0 and 2.4%, respectively (n=10). The validity of the developed IL-CPE approach was confirmed by the analysis of certified reference materials (NIST-1641d mercury in natural water and NCS ZC81002B human hair). The applicability of proposed IL-CPE technique was demonstrated successfully by estimation of trace mercury in real water, food and hair samples.

Objective: An eco-friendly, simple and sensitive vortex-assisted ionic liquid-based dispersive liquid-liquid microextraction method (VA-IL-DLLµE) has been proposed to enrich and determine trace levels of cadmium (Cd2+ ) and lead (Pb2+ ) ions in water, vegetables and tobacco samples, prior to its FAAS determination. Methods: The proposed method based on utilization of ionic liquid (IL) (1-hexyl-3-methylimidazolium tris(pentafluoroethyl)trifluorophosphate [HMIM][FAP]) as an extraction solvent for both ions after the complexation with 4,5-dihydroxy-3-phenylazo-2,7-naphthalenedisulfonic acid, disodium salt (Chromotrope 2R) at pH 6.5. The impact of different analytical parameters on microextraction efficiency was optimized. Results: In the ranges of 1.0–300 and 2.0-400 μg/ml, the calibration graphs were linear. The limits of detection were 0.3 and 0.6 μg/ml for Cd2+ and Pb2+ ions, respectively. The preconcentration factor was 100. The relative standard deviation (RSD %)<3.0%, which indicates the proposed method has high precision. Conclusion: The proposed VA-IL-DLLµE method was developed and applied for the estimation of Cd2+ and Pb2+ ion content in various water, vegetables and tobacco samples, and satisfactory results were obtained. The obtained recovery values showed good agreement with the certified values.