Analytica, Volume 3, Issue 4 (December 2022) – 6 articles

The body of work described in this research paper evaluates the compatibility between Fenbendazole (Fen), which is a broad-spectrum anthelmintic with promising antitumor activity, and three polymeric excipients commonly applied in pharmaceutical dosage forms. The assessment of binary mixtures was performed by differential scanning calorimetry and thermogravimetric analysis/derivative thermogravimetry to predict physical and/or chemical interactions, followed by X-ray diffraction spectroscopy (XRD), Fourier transform infrared spectroscopy (FTIR), and high-performance liquid chromatography (HPLC) to confirm or exclude any interactions. Thermal studies suggested the presence of interactions between Fen and P 407, PCL, and PLA. To validate these data, XRD showed that Fen is compatible with PCL and PLA, suggesting some interaction with P 407. FTIR demonstrated that PCL and PLA can establish physical interactions with Fen; moreover, it suggested that P 407 interacts not only physically but also chemically, which was later proved by HPLC to be only new intermolecular interactions. This work supports the further application of P 407, PCL, and PLA for the development of new medicinal and veterinary formulations containing Fen, since they do not affect the physical and chemical characteristics of the active ingredient and consequently its bioavailability and therapeutic efficacy. Full article

Green(er) sample preparation technologies still dominate as the anticipated improvement in all analytical protocols. Separation scientists all over the world continuously strive to comply with the Green Analytical Chemistry (GAC) demands. To follow this trend, microextraction techniques are constantly evolving to bridge the gap between Green Analytical Chemistry and sample pretreatment. A research group from Florida International University, Miami, Florida has introduced fabric phase sorptive extraction (FPSE) in 2014 that was considered as a new milestone in microextraction technologies at that time. Two years later, the same research group introduced an advantageous innovative configuration that combines the stirring and extraction mechanism into a single sample preparation device, keeping all the benefits originally offered by classical FPSE. Magnet integrated fabric phase sorptive extraction (MI-FPSE) was eventually introduced as a new, advantageous implementation of FPSE. This device exhibits the advantageous role of the increase in extraction kinetics through sample diffusion, resulting in improved extraction efficiency of the microextraction device and supports the need for combining processes for better promotion and implementation of the principles of Green Analytical Chemistry. The applications of MI-FPSE are presented herein, showing the essential role that this technique can play in analytical and bioanalytical sample preparation. Full article

Picloram and 2,4-D are systemic herbicides used to control a wide range of broad-leaved weeds and post-emergence annual and perennial broad-leaved weeds, respectively. The use of plant protection products containing Picloram and 2,4-D necessitates the development of analytical methods, useful for the laboratories focused on control, for monitoring. In this study, we designed and validated an analytical method for the rapid determination of picloram and 2,4-D by HPLC-DAD. The method involves the extraction of the substances by sonication of the sample with methanol, followed by dilution in acetonitrile, and direct injection on a liquid chromatography system, based on the use of a Gemini C18 column. We used an isocratic mobile elution consisting of acetonitrile and water acidified 1% with H₃PO₄ (50:50, v/v). We validated the proposed method, which demonstrated linearity within the concentration range of 0.01–0.028 mg/mL for picloram and 2,4-D, with a correlation coefficient (R²) of 0.9993 for picloram and 0.9999 for 2,4-D. We considered precision, repeatability and selectivity in the validation. The repeatability of the method expressed as percent of relative standard deviation (%RSD) was lower than 1% for both substances. The proposed method is suitable for the simultaneous determination of picloram and 2,4-D in pesticide formulations. Full article

In spite of the application of different cleaning procedures, the marble used for the portrait bust of Queen Margherita di Savoia continued to show permanent discoloration, consisting of an unevenly distributed grayish alteration, mainly on the front part. In this work, a multi-analytical, non-invasive approach was proposed using spectrocolorimetry, reflectance spectroscopy and multispectral imaging. The initial assumption, suggesting the presence of altered protective materials based on organic products (such as waxes or oils,) applied in the past according to traditional practices, was excluded, revealing instead the presence of deposits of particulate matter, which penetrated inside the crystalline structure of the marble, leading to a variation in its shade. Cleaning tests were also carried out to define the best product, using sustainable chemicals such as Polar Varnish Rescue^®, alkoxyde surfactant, disodium EDTA, GLDA and Politect^® Base in order to identify the best methodology and materials for sustainable cleaning, respecting the integrity of the original matter. Politect^® Base demonstrated better action in comparison to the other products tested, and similar results were obtained with GLDA, which could be applied in areas where the Politect^® is less efficient (e.g., lace). Full article

Starch is a polysaccharide that is abundantly found in nature and is generally used as an energy source and energy storage in many biological and environmental processes. Naturally, starch tends to be in miniscule amounts, creating a necessity for quantitative analysis of starch in low-concentration samples. Existing studies that are based on the spectrophotometric detection of starch using the colorful amylose–iodine complex lack a detailed description of the analytical procedure and important parameters. In the present study, this spectrophotometry method was optimized, tested, and applied to studying starch content of atmospheric bioaerosols such as pollen, fungi, bacteria, and algae, whose chemical composition is not well known. Different experimental parameters, including pH, iodine solution concentrations, and starch solution stability, were tested, and method detection limit (MDL) and limit of quantification (LOQ) were determined at 590 nm. It was found that the highest spectrophotometry signal for the same starch concentration occurs at pH 6.0, with an iodine reagent concentration of 0.2%. The MDL was determined to be 0.22 μg/mL, with an LOQ of 0.79 μg/mL. This optimized method was successfully tested on bioaerosols and can be used to determine starch content in low-concentration samples. Starch content in bioaerosols ranged from 0.45 ± 0.05 (in bacteria) to 4.3 ± 0.06 μg/mg (in fungi). Full article

A fluorescence off-on method for the detection of Sorghum mosaic virus (SrMV) based on fluorescence resonance energy transfer (FRET) was developed in this study. The biosensor was realized by the adsorption of SrMV coat protein (CP) on gold nanoparticle (AuNP) and conjugation of anti-SrMV antibody (Ab) on cadmium telluride quantum dot (CdTe QD). The optimum quenching efficiency was about 50% obtained at a CdTe QD-Ab/AuNP-CP ratio of 1:7. Moreover, the feasibility of the developed biosensor was verified by the detection of purified CP and the limit of detection was estimated as 0.02 μg/mL. This strategy was also successfully applied to monitor SrMV CP in plant sap with a recovery rate between 97.7 and 107.4%. The developed biosensor is a simple, rapid, and efficient technique which does not need excessive washing and separation steps. Full article