Utilizing two different sustainable and green spectrophotometric approaches using derivative ratio spectra for the determination of a ternary severely overlapped mixture: application to veterinary formulation

Mathematical manipulation technique has proven to be a very powerful tool for efficient processing and handling of highly overlapped spectra. This work introduced two green and sustainable approaches for the successful recovery of the ternary mixture, Tylosin tartarate (TYL), Sulfadimdine (SLD), and Trimethoprim (TRI). The approaches were constructed using three different methods, derivative ratio spectrum zero-crossing method (DRSZ), double divisor ratio spectra derivative method (DDRD), and factorized derivative ratio method coupled with spectrum subtraction (FDRM-SS). The two approaches succeeded in recovering the three drugs (Linearity range achieved were 0.5-5 µg/mL for TYL, 0.3-1.3 µg/mL for SLD, and 0.3-5 µg/mL for TRI), giving convenient standard deviations and satisfactory recovery percentages. The recommended methods have been verified in accordance with (ICH) guidelines. When the results were statistically compared to the official methods, no significant difference was found. Both AGREE-Analytical GREEnness Metric Approach and Software, and White Analytical Chemistry (WAC) RGB model gave scores of 0.93 and 97.2%, respectively, which proved that the approaches were eco-friendly and abiding by the sustainability principles.

Validation of UHPLC-ESI-MS/MS Method for Determining Steviol Glycoside and Its Derivatives in Foods and Beverages

The aim of this study was to validate a method for determining nine types of steviol glycoside and its derivatives in food and beverage products, using ultrahigh-performance liquid chromatography tandem mass spectrometry with electrospray ionization (UHPLC ESI MS/MS). The performance characteristics of the analysis method were determined along with their suitability for the intended use. Coefficient of determination (R2) calibration curves from 0.2 to 1.0 mg L-1 were in the ranges of 0.9911-0.9990, 0.9939-1.0000 and 0.9973-0.9999 for a beverage, yogurt and snack, respectively. Intra-day precisions in terms of percent relative standard deviation (% RSD) of concentration, at 0.2, 0.5 and 1.0 mg L-1, for the beverage, yogurt and snack were lower than 15% (1.1-9.3%). At all concentrations, percentage recoveries were in the accepted range of 70-120%. For the matrix effect study, matrix-matched calibration was used for all compounds, obtaining a linear concentration range from 0.2 mg L-1 to 1.0 mg L-1. Almost all matrix-matched results presented as percentage recoveries were within the accepted range of 80-120%. The limit of detection (LOD) for steviol glycosides ranged from 0.003 to 0.078 μg g-1, while the limit of quantitation (LOQ) ranged from 0.011 to 0.261 μg g-1. These results indicate that the modified test method can be applied to determine the presence of steviol glycoside and its derivatives in a wide range of sample matrices.

Determination of Mycotoxin Contamination Levels in Rice and Dietary Exposure Assessment

The contamination by aflatoxins, ochratoxin A, and zearalenone of samples of paddy and polished rice stored in silos located in Chiriquí, Panama, was evaluated. A total of 23 samples were extracted using immunoaffinity columns and analyzed by high-performance liquid chromatography (HPLC) with a fluorescence detector (FLD) and post-column photochemical derivatization. For the method used, the detection limits were lower than 0.25 μg/Kg for aflatoxins (AFB1, AFB2, AFG1, AFG2) and ochratoxin A and 9.35 μg/Kg for zearalenone; the limits of quantification were between 0.25 and 18.75 μg/Kg, respectively. Of the samples analyzed, all of the paddy rice samples were positive for at least one of the mycotoxins studied, zearalenone being the one found with the highest incidence (90.91%); for the polished rice samples, the mycotoxin with the highest incidence was zearalenone (50%), although in concentrations lower than those established in European legislation (100 μg/Kg). The estimate of the daily zearalenone intake according to the concentrations found was always less than 0.07 μg/Kg/bw. This is the first report on the determination of 6 mycotoxins in rice grains from Panama by the HPLC-FLD methodology. Considering the high incidence of mycotoxins in the analyzed rice samples, regular control in the production process is recommended to improve quality and ascertain its safety.