In recent times, the counterfeiting of pharmaceuticals has been considered a serious trouble especially in developing countries that acquire poor inspection programs. Sildenafil, vardenafil and tadalafil (phosphodiesterase type 5 inhibitors) products have gained wide popularity in treating sexual disorders, for which they are subjected to counterfeiting. For this purpose, a simple, rapid, and novel HPLC method with ultraviolet detection has been simply developed for the simultaneous determination of vardenafil, sildenafil, and tadalafil, and their counterfeits (dapoxetine, paroxetine, citalopram, tramadol and yohimbine) in pharmaceutical dosage forms and counterfeit products such as instant coffee and honey. The separation was carried out on a C₁₈ column, with acetonitrile and an aqueous 0.05% formic acid solution as the mobile phase with a gradient program and at a flow rate of 1 mL min⁻¹. UV detection was accurately set at 230 nm. The total run time was 11 min for elution of these eight drugs. A UPLC-MS/MS method was also developed, by which compounds were separated in only 6 min, and it was used as a confirmatory tool for studied compounds by identification of their mass spectra. Proposed methods were validated by following ICH guidelines. Both methods were found to be linear, specific, precise and accurate, and they were efficiently applied to analyze 50 commercial products including honey sachets, instant coffee and pharmaceutical products marketed as aphrodisiacs and suspected to contain PDE5-inhibitors.

Overexposure to food colorants above the allowed daily intake (ADI) level can provoke hyperactivity and other disturbed behaviors especially in children. Two new methods were developed to separate five synthetic colorants, which were Tartrazine (E102), Sunset Yellow (E110), Allura Red (E129), Carmoisine (E122), and Brilliant Blue (E133). They are labeled on a large variety of commercial food products in the Egyptian market without mentioning their definite concentrations. Therefore, there was a real need to determine these colorants with simple, accurate, and fast methods. This is the first study to determine these colorants in a wide variety of food products present in the Egyptian market. The HPLC approach with photodiode array detection was developed to quantify these colorants, on a C18 column, with a mobile phase composed of acetonitrile and water containing 1% ammonium acetate (pH 6.8), separation was carried out using a gradient program. The colorants were eluted and efficiently separated within 9 min. Then, as a complementary technique to HPLC, the UPLC-ESI–MS/MS approach was developed for identification and accurate mass measurement of the colorants found in high concentrations, the colorants were obtained simultaneously in negative mode, the run time was only 3 min. These developed methods were validated according to ICH recommendations and they were applied to analyze 65 food products including jelly powder, puddings, ice cream powders, concentrated soft drink powders, carbonated drinks, chewing gums, and sugar confectionery.

In this study, a Quick, Easy, Cheap, Effective, Rugged and Safe method (QuEChERS) method was optimised to extract 30 pesticides which are the most used in Egypt in soil and drainage water. Optimisation was performed by Experimental Design expert 7.1 to get better recoveries. The procedure combined with a developed GC-MS for determination of these pesticides. Total analysis time was 36 min with 1 ml injection volume. The limit of quantification (LOQ) was ranged between 4.59 ng/ml, and 15.91 ng/ml for all pesticides. Most standard deviations were in the range between 0.41 and 1.41 indicating satisfactory accuracy. The validated method was applied to Egyptian soil and drainage water samples brought from different places in Damietta city. Dimethoate, β-Endosulfan, DDD, Malathion, Vinclozolin, DDT, Endrin, Cyprodinil, Primiphos ethyl, Tetradifon, Parathion ethyl and Diazinon were detected and quantified. So risk assessment on human health should be considered especially for those pesticides.

One of the most applied procedures for the determination of trace analytes in complex matrices is QuEChERS (an acronym for Quick, Easy, Cheap, Effective, Rugged, and Safe). QuEChERS procedures include an extraction step followed by a dispersive solid-phase extraction (dSPE) for analytes cleaning-up from the matrix components. A challenging task in QuEChERS procedures is extracting and determining pesticides from samples of high fat such as milk samples. This challenge induced the innovation of new adsorbents for the clean-up step such as Z-Sep Plus® and EMR-Lipid® to enable removal of fatty matrix components without affecting the recovery of hydrophobic analytes. This work aims to apply experimental design to optimize the combined application of both QuEChERS clean-up adsorbents; Z-Sep Plus® and EMR-Lipid® in addition to other QuEChERS parameters in the determination of eight pesticides: hexachlorocyclohexane, dichlorodiphenyldichloroethane, dichlorodiphenyltrichloroethane, primiphos ethyl, diazinon, malathion, endrin, and dimethoate in milk matrix. This was augmented by optimization of GC–MS/MS and UPLC-MS/MS to detect and determine analytes in extracts. The experimental design of QuEChERS procedure enabled the optimization of Z-Sep Plus®- and EMR-Lipid®-added adsorbent amounts with other method parameters to enable the maximum recovery of analytes. Furthermore, the optimized methods enabled low detection limits of the studied pesticides within a short analysis time (28 min for GC and 12 min for LC methods, respectively). The procedure was validated according to European SANTE/11312/2021 Guideline. Quantitation limit ranged from 1.7 to 3.2 ng/mL for GC–MS/MS method and from 1.7 to 3 ng/mL for UPLC-MS/MS method. Greenness assessment of the methods followed four approaches indicating an excellent value of greenness for the proposed methods. Furthermore, 45 real milk samples collected from the Egyptian market were tested with the developed procedure for the presence of pesticides.

Implementing green analytical techniques has been one of the main objectives of the analytical chemistry community for the past two decades. The aim of transitioning to green analytical chemistry is to establish new methods environmentally benign instead of traditional methods. According to WHO, 20 million people worldwide are affected by schizophrenia, and 45 million people worldwide are affected by bipolar disorders. For that, in this work we develop a green HPTLC method to quantify simultaneously the four antipsychotics chloropromazine HCl, asenapine maleate, quetiapine fumarate and aripiprazole in pure form and tablet formulations. In this chromatographic method, separation was performed using silica gel 60 F254 HPTLC plates, the mobile phase composed of binary mixture of green solvents (ethanol : water (9 : 1 v/v)) which gave compact band with Rf values ranged between 0.14 to 0.70 for the drugs. The method was validated for linearity, accuracy, precision, selectivity and robustness according to ICH guidelines. It was assessed for greenness by analytical Eco-scale and compared with reported HPTLC methods for single analysis of these antipsychotics.