Origins of Green Analytical Chemistry

Valorization of Peanut Skin as Agricultural Waste Using Various Extraction Methods: A Review

Peanuts (Arachis hypogea) can be made into various products, from oil to butter to roasted snack peanuts and candies, all from the kernels. However, the skin is usually thrown away, used as cheap animal feed, or as one of the ingredients in plant fertilizer due to its little value on the market. For the past ten years, studies have been conducted to determine the full extent of the skin's bioactive substance repertoire and its powerful antioxidant potential. Alternatively, researchers reported that peanut skin could be used and be profitable in a less-intensive extraction technique. Therefore, this review explores the conventional and green extraction of peanut oil, peanut production, peanut physicochemical characteristics, antioxidant activity, and the prospects of valorization of peanut skin. The significance of the valorization of peanut skin is that it contains high antioxidant capacity, catechin, epicatechin resveratrol, and procyanidins, which are also advantageous. It could be exploited in sustainable extraction, notably in the pharmaceutical industries.

Overview of Analytical Methods for Evaluating Tinidazole

BACKGROUND

Tinidazole (TIN) has amoebicidal, giardicidal, antifungal, and antimicrobial activities. It is marketed in the form of tablets. Analytical methods to assess the quality of TIN-based products are essential for correct pharmacotherapy.

OBJECTIVE

The objective of this review is to show an overview of the existing analytical methods for evaluating TIN, according to the quality control (QC) analysis routine and green analytical chemistry (GAC).

RESULTS

Official compendia show a method for evaluating TIN in tablets by nonaqueous titration, which has limitations (materials on the mg scale using solvents considered not recommended and harmful). The literature shows some analytical methods for evaluating TIN, both physicochemical and microbiological. The most used physicochemical method is UV (41%), and second is HPLC (28%). Among the microbiological methods, agar diffusion and turbidimetric methods are equally divided. The most studied matrix is TIN tablets (73%), and the most used solvent is methanol.

CONCLUSIONS

The literature shows space for the development of analytical methods according to GAC for evaluating TIN, optimizing time, resources, and materials, reducing waste generation, and opting for less aggressive reagents, solvents, and diluents.

HIGHLIGHTS

This review shows the status of analytical methods, both physicochemical and microbiological, for the analysis of TIN in pharmaceutical matrix, in the context of routine analysis of the chemical-pharmaceutical industries and of GAC.

A Novel Green Micellar HPLC-UV Method for the Estimation of Vandetanib in Pure Form, Human Urine, Human Plasma and Human Liver Microsomes Matrices with Application to Metabolic Stability Evaluation

Vandetanib (Caprelsa^®; VNB) is a prescription medicine that is used for the treatment of medullary thyroid cancer that has disrupted other body parts or that cannot be removed by surgery. It is considered a tyrosine kinase inhibitor (TKI). Fast, sensitive and validated HPLC-UV was established for VNB quantification in pure human biological fluids (urine and plasma) and human liver microsomes (HLMs). This analytical methodology was applied also to the metabolic stability assessment of VNB. This method was performed using a phenyl column (250 mm × 4.6 mm id, 5 µm particle size). A sodium dodecyl sulphate solution (0.05 M, pH 3.0 using 0.02 M orthophosphoric acid) containing 0.3% triethylamine and 10% n-butanol was used as a mobile phase and was pumped isocratically at a flow rate of 0.7 mL/min and at a 260 nm detection wavelength. The total elution time was 6 min with an injection volume of 20 μL. The linearity of the established methodology ranged from 30 to 500 ng/mL in pure form and 50 to 500 ng/mL (r² ≥ 0.9994) in human biological fluids and HLMs. No significant interference from the matrix components was observed. The proposed methodology revealed the benefits of being green, reliable and economic.

Extraction of Natural Fragrance Ingredients: History Overview and Future Trends

For centuries, perfumes consisted in a combination of natural ingredients, mainly of plant origin. From the 19th century on, the advent of organic synthesis enabled the deployment of multiple synthetic olfactory notes, enriching significantly the perfumers' portfolio. Chemistry is ever since the foundation of modern perfumery. However, sustainable-minded consumers, massively rejecting synthetics for safety and ecological issues, engaged a global return to nature in numerous sectors, and the fragrance industry is not outdone. Sustainable extraction of natural products, making use of innovative technologies, process intensification and agro-based solvents, constitutes the answer to develop eco-conceived fragrant ingredients covering every olfactory family without endangering biodiversity any further. The objective of this review is to draw a clear picture of where those technological advances are today and to assess the ones that may be effectively transposed at the industrial scale tomorrow.

Gloeothece sp. as a Nutraceutical Source-An Improved Method of Extraction of Carotenoids and Fatty Acids

The nutraceutical potential of microalgae boomed with the exploitation of new species and sustainable extraction systems of bioactive compounds. Thus, a laboratory-made continuous pressurized solvent extraction system (CPSE) was built to optimize the extraction of antioxidant compounds, such as carotenoids and PUFA, from a scarcely studied prokaryotic microalga, Gloeothece sp. Following "green chemical principles" and using a GRAS solvent (ethanol), biomass amount, solvent flow-rate/pressure, temperature and solvent volume-including solvent recirculation-were sequentially optimized, with the carotenoids and PUFA content and antioxidant capacity being the objective functions. Gloeothece sp. bioactive compounds were best extracted at 60 °C and 180 bar. Recirculation of solvent in several cycles (C) led to an 11-fold extraction increase of β-carotene (3C) and 7.4-fold extraction of C18:2 n6 t (5C) when compared to operation in open systems. To fully validate results CPSE, this system was compared to a conventional extraction method, ultrasound assisted extraction (UAE). CPSE proved superior in extraction yield, increasing total carotenoids extraction up 3-fold and total PUFA extraction by ca. 1.5-fold, with particular extraction increase of 18:3 n3 by 9.6-fold. Thus, CPSE proved to be an efficient and greener extraction method to obtain bioactive extract from Gloeothece sp. for nutraceutical purposes-with low levels of resources spent, while lowering costs of production and environmental impacts.

SIMCA Modeling for Overlapping Classes: Fixed or Optimized Decision Threshold?

An approach exploiting the principles of Receiver Operating Characteristic (ROC) curves for the simultaneous optimization of both the complexity and the decision threshold in Soft Independent Modeling of Class Analogy (SIMCA) classification models is here proposed. The outcomes resulting from the analysis of two simulated and four real case-studies highlight that, in the presence of strong overlap among various categories of samples, the implemented method can lead to better classification efficiency in external validation, compared to fixing such a threshold a priori. This guarantees a higher robustness toward class dispersion. On the other hand, in cases of clearer and more definite separation among the different groups of observations, their classification performance is equally satisfactory for test samples.

Green bioanalysis: some innovative ideas towards green analytical techniques

The key target of green chemistry is to make compounds and materials available to mankind, while causing no harm to the environment. In the 21st century analytical scientists are more concerned about green analytical method development. The number of literatures on green chemistry has undergone a dramatic increase in the new millennium. Green bioanalytical techniques aim to minimize or eliminate the hazardous waste associated with bioanalytical methods. An efficient and sincere approach towards bioanalytical method development has an enormous contribution towards green analysis. The selection of organic constituents of the mobile phase, choice of sample extraction process, adoption of an appropriate separation procedure and a few others, control the green chemistry approach of the bioanalytical method. In routine practice, UHPLC–MS can be the most suitable approach, while supercritical fluid chromatography is one of the best available techniques for green bioanalytical methods. Nevertheless, there always remains great scope of further research on green bioanalytical methods.

Pressurized liquid extraction as a green approach in food and herbal plants extraction: A review

Pressurized liquid extraction is a "green" technology for the extraction of nutraceuticals from foods and herbal plants. This review discusses the extraction principles and the optimization of the extraction parameters that improves the extraction efficiency. The use of different solvent mixtures and other extraction additives to enhance the efficiency of the extraction are discussed. Dynamic mode of extraction in Pressurized liquid extraction, and the use of combined and hyphenated sample preparation and analytical techniques are presented. This work discusses how different studies used Pressurized liquid extraction to enrich phenolic compounds, lignans, carotenoids, oils and lipids, essential oils and other nutraceuticals from foods and herbal plants.