Volume 40, Issue 1

A modern development discusses the synthesis and validity of simple, sensitive, and versatile spectrophotometric methods for Bi(III) and Al(III) determination in pharmaceutical formulations have been conducted. In the present paper, 4-(4 acetamidophenylazo) pyrogallol has been synthesized as a new organic compound, 4-APAP, by coupling pyrogallol in a regulated pH medium with diazotized p-aminoacetanilide. 4-APAP was identified by methods of FT-IR, 1H-NMR, 13C-NMR, and thermal analysis (thermogravimetry and differential scanning calorimetry). Solvatochromic activity was also studied in solvents with different polarities. The Kamlet and Taft linear solvation energy relationship was used to correlate shifts in UV-Visible spectra of 4-APAP with Kamlet-Taft parameters (α, β, and π*). The optimum assay conditions showed linearity from 0.3–13 to 0.5–11 μg·mL −1 for Bi(III) and Al(III), respectively. Molar absorptivity values were 3.365 × 10 4 and 0.356 × 10 4 L·mol −1 ·cm −1 for Bi(III) and Al(III), with similar Sandell's sensitivity measures of 0.006 and 0.008 μg·cm −2 . Detection limits and quantification limits were 0.013 and 0.043 μg·mL −1 for Bi(III), respectively, and 0.018 and 0.059 μg·mL −1 for Al(III) with the relative standard deviation for determination of both metal ions using 4-APAP probe being <2.0%. The validity, accuracy, and efficiency of the approaches were demonstrated by the determination of Bi(III) and Al(III) in different formulations.

Two new potentiometric sensors were created for the quantification of bisoprolol fumarate and alverine citrate in bulk pharmaceutical dosage forms and human serum. Bisoprolol and alverine sensors were manufactured by combining potassium tetrakis ( p -chlorophenyl) borate ion pairs to serve as electroactive substances, plasticized poly (vinyl chloride) matrix membranes, and o -nitrophenyl octyl ether. They demonstrated high responses over the concentration ranges of 1.0×10 −6 to 1.0×10 −2 mol L −1 bisoprolol and alverine with close to Nernstian cationic slopes of 52 and 56 mV decade −1 , respectively. The detection limits for bisoprolol and alverine were 2.6×10 −6 and 1.75×10 −6 mol L −1 , respectively. For both medications, the response time was instantaneous (2.0 s). The working pH ranges for bisoprolol and alverine were 4.50–8.50 and 2.00–8.80, respectively. For both sensors, the life cycle was long (3 months). The sensors were used in pharmaceutical dosage types for the assay of bisoprolol and alverine, recording average recoveries of 99.40% and 99.98% respectively and were also successfully used for estimating the two drugs in human serum with an average recovery of 99.60% for both drugs. For all multiple staged interfering materials, the reported latest potentiometric sensor methods displayed high selectivity. The current sensor obtained a high percentage recovery and an excellent relative standard deviation compared with those obtained from previously published methods.

A new organic molecule probe has been introduced as a “turn-off” fluorescent sensor to detect trace quantities of UO 2 2+ in the presence of several transition metals with promising results. The procedure is based on quenching the fluorescence intensity of 6-chloro-2 H -1,2,4-benzothiadiazine-7-sulfonamide 1,1-dioxide ( L ) in the presence of various UO 2 2+ concentrations in methanol. The UO 2 2+ and L species interact through electrostatic interaction between negatively charged nitrogen atom of the sulfonamide group of L and positively charged UO 2 2+ , thus facilitating the non-radiative recombination of UO 2 2+ and L through the charge transfer or electron transfer processes and leading to the fluorescence quenching of L . The mechanism of quenching was addressed and proved to be static quenching. The impressive quenching of the fluorescence intensity of L by different concentrations of UO 2 2+ has been successfully used as a new sensor to measure UO 2 2+ in methanol at λ ex = 340 nm, λ em = 380 nm with a linear dynamic range of 0.08–5.0 µM and detection limit and quantification limit of 0.0276 and 0.0837 µM, respectively. The L sensor shows interesting advantages compared to other developed sensors with adequate performance, such as broader linear range and lower detection limit, selectivity, and simplicity, which illustrate its useful practical use. Graphical abstract Fluorescence quenching detection of UO 2 2+ in aqueous solution based on an organic molecule probe of 6-chloro-2 H -1,2,4-benzothiadiazine-7-sulfonamide 1,1-dioxide.

To determine the trace amount of four benzoic acid esters in cosmetics, ionic dispersive liquid–liquid microextraction (DLLME) and magnetic solid-phase extraction were combined and optimized. After solvent optimization, 1-octyl-3-methylimidazolium hexafluorophosphate was selected as the extraction solvent to form hydrophobic droplets in the process of ionic DLLME, followed by removal of ions from the sample solution containing Fe 3 O 4 @GO nano-materials. The magnetic nano-materials were characterized using Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, and vibrating sample magnetometer. Some parameters affecting the efficiency of extraction were optimized using Box-Behnken design. Under optimized conditions, the limit of detection for all the preservatives was less than 0.135 mg/L and the accuracy ranged from 88.5% to 101%. This technology could determine the trace amount of preservatives in cosmetics with comparatively higher accuracy and sensitivity.

Sensitive DNA assays are of importance in life science and biomedical engineering, but they are heavily dependent on thermal cycling programs or enzyme-assisted schemes, which require the utilization of bulky devices and costly reagents. To circumvent such requirements, we developed an isothermal enzyme-free DNA sensing method with dual-stage signal amplification ability based on the coupling use of catalytic hairpin assembly (CHA) and Mg 2+ -dependent deoxyribozyme (DNAzyme). In this study, the sensing system involves a set of hairpin DNA probes for CHA (ensuring the first stage of signal amplification) as well as ribonucleobase-modified molecular beacons that serve as activatable substrates for DNAzymes (warranting the second stage of signal amplification). An experimentally determined detection limit of about 0.5 pM is achieved with a good linear range from 0.5 to 10 pM. The results from spiked fetal bovine serum samples further confirm the reliability for practical applications. The non-thermal cycling, enzyme-free, and dual-amplified features make it a powerful sensing tool for effective nucleic acid assay in a variety of biomedical applications.

The widespread coronavirus 2019 (COVID-19) pandemic, attributed to the severe acute respiratory syndrome coronavirus-2, has resulted in global lockdowns and excess mortality. Remdesivir (RM) is the first and only antiviral drug that the US Food and Drug Administration (FDA) has approved so far for COVID-19. The treatment protocol involves multidrug combinations, basically depending on RM, in addition to antimicrobials, antipyretics, corticosteroids, and anticoagulants. This study develops and validates sensitive and selective RM screening in spiked human plasma in the presence of commonly co-administered drugs. Hydroxychloroquine, azithromycin, paracetamol, dexamethasone, and anticoagulants (rivaroxaban and edoxaban) have been detected simultaneously with RM in the same biological matrix. Separation has been efficiently achieved by simple reversed phase HPLC with dual detectors. Diode array detector and fluorimetric detection have been used to compare their sensitivity and selectivity. Both assays have been validated according to bioanalytical FDA validation parameters. Chromatographic separation and quantitation of RM along with concomitant drugs instantly bioscreen COVID-19 multiple therapy medication in 10 min run time. Furthermore, the proposed in vitro study takes the lead for prospective testing of possible drug–drug interactions that alter the pharmacokinetic profiles of drugs.

Volatile organic compounds are released by different sources causing air pollution. Moreover, some of these carbon-based organic chemicals are considered as biomarkers in the exhaled breath of individuals and can be used to identify various kinds of diseases. Hence, the increasing demand to control air quality and human health has promoted the development of monitoring systems based on high-performance gas sensing structures. This review highlights the achievements in sensing technologies for the detection of volatile organic compounds. Particularly, chemiresistive gas sensors and detection systems based on the terahertz spectroscopy method are outlined. The progress in research studies is discussed and the potential of both techniques is evaluated considering the current challenges. Afterward, a brief summary is also provided along with the advances and issues for future investigations and the manufacturing of highly sensitive and selective monitoring systems.

Cilostazol (CLZ) is a quinolinone derivative possessing anti platelet and vasodilating properties and it is used in the treatment of intermittent claudication. It operates by inhibiting the cyclic guanosine monophosphate (cGMP) dependent phosphodiesterase III which leads to availability of cyclic adenosine monophosphate (cAMP) in blood vessels and platelets owing to vasodilation and reduced calcium-induced contractions. This article illustrates the various reported quantitative methods which can be used to determine cilostazol and its metabolites either alone or in combination forms in pharmaceutical preparation or biological matrices like plasma, serum, and urine. The review covers analytical methods like ultraviolet spectroscopy, fluorescence spectroscopy, electrometric methods, nuclear magnetic resonance spectroscopy, high performance liquid chromatography, high performance thin layer chromatography, ultra-high performance liquid chromatography, and tandem mass spectroscopy from the year 1985 to 2019 with a brief explanation on every analytical method. Among the methods, it was found that most researchers opted for UV and HPLC analytical methods for the estimation of cilostazol.

Even very low concentrations of heavy metal pollutants have adverse effects on the environment and on human health. Thus, determining even trace concentrations of heavy metals in various samples has attracted a lot of attention. The conventional analytical methods used for the sampling and analysis of heavy metals have some limitations, including the effects of the matrix and their high detection limits. Thus, various methods are used for the pretreatment and concentration of the target analytes, and these methods are time-consuming, expensive, and require the use of toxic solvents. In recent years, supramolecular solvent-based microextraction (SSME), a green analytical strategy, has been used to determine low concentrations of heavy metals in various matrices. This method has unique features such as high enrichment factor, short extraction time, and rapid analysis. In addition, it is cost effective because it consumes less chemical reagents than other methods. Also, it is ecofriendly, and it has good sensitivity and selectivity. Herein, we presented a comprehensive review of the application of the SSME technique for the analysis of heavy metals in water, food, and biological samples. Also, we have provided the distinctive properties of the SSME technique, discussed the challenges that lie ahead, and addressed the potential future trend.

This manuscript is a critical review of the analytical methods reported in the existing literature for the determination of mycotoxin patulin at trace/ultra-trace levels in food matrices. The article starts focusing on what mycotoxins are, their “analytical history” (more than 21,000 articles published in Scopus database): each mycotoxin is specific for a given fungus and shows toxic effects, some even being carcinogenic. Most International regulations on mycotoxins are also reported, which pertain official controls in the food chain as well as the sampling methods and the maximum tolerable limits of mycotoxins. Then the manuscript is focused on patulin, a mycotoxin that is mainly produced by the fungal species Penicillium expansum . The main characteristics and properties of patulin are discussed, including its biosynthesis, especially on stored fruits infected by P. expansum and derived products, its toxicology, and some strategies aiming at preventing and/or reducing its presence. The description of the analytical procedure for patulin starts from sampling: the extraction and analytical methods reported are based on the official protocol of the Association of Official Analytical Chemists, which relies on the high-performance liquid chromatography-ultraviolet/diode array detector (HPLC-UV/DAD). Furthermore, an in-depth discussion of the most suitable analytical methods is reported. The first analytical step regards the analyte(s) extraction from the sample, followed by a clean-up phase, and by a final quantitative determination. This last section is divided into reference or confirmation methods, rapid screening and new methods and expected results, i.e., qualitative, quantitative, or semi-quantitative. Reference methods include TLC, GC, HPLC, and MS, whereas rapid methods include enzyme immunoassay tests, dipsticks, and lateral flow tests. Novel analytical methods include fluorescence, near infrared spectroscopy, capillary electrophoresis, and biosensors. Finally, the official method is compared with others present in the literature allowing a multi-target analysis, and its use in combination with other techniques of molecularly imprinted polymers is discussed.

Food safety and quality have gained much attention and the capability to evaluate food quality and safety in a sensitive, rapid, and reliable manner is of great importance in the food industry. Surface-enhanced Raman scattering (SERS) with the advantages of excellent sensitivity, high selectivity, non-destructive nature, and significant enhancement to identify the target has demonstrated a great potential for quick detection of the food sample. The enhancement of Raman signals for SERS is not only related to the interactions between substrates and samples but also the functionalization of substrates to gain SERS active substrates. In the present review, this paper summarized the progress of SERS quantitative analysis and application in food safety detection. The future trends and perspectives were also given.

Neonicotinoid insecticides are widely used to kill and prevent unwanted insects from attacking growing crops. Extensive use of insecticides in various compartments of the environment has led to adverse effect on the health of living organisms. Several analytical methodologies have been reported for extraction and quantification of neonicotinoid insecticides in various matrices. The analytical detection techniques range from traditional to modern or state of the art quantification methods. The traditional analytical techniques include gas chromatography and high-performance liquid chromatography. These methods require extensive sample pretreatment before identification, separation, and quantification of target analytes. Advanced detection techniques refer to the sensor technologies based on optical, biorecognition, molecular imprinted polymers chemical, and piezoelectric. In this review, a summary and explanation of the various traditional analytical and advanced methodologies for extraction, separation, detection, and quantification of neonicotinoid insecticides residue in water samples have been discussed.

Accurate, precise, and rapid analytical monitoring of various nuclear materials is essential for the smooth functioning of nuclear reactors. Ion chromatography (IC) has emerged as an effective analytical tool for simultaneous detection of different ions in a wide range of materials used in the nuclear industry. The major advantages over other techniques include superior selectivity and sensitivity for detection of anions and cations, wide dynamic range, and speciation studies of ions. This article provides an overview of different ion chromatographic methodologies developed for the analyses of various nuclear materials such as fuel, control rods, moderator, coolant, and process streams. Comparison of various analytical aspects of IC over the other routine techniques reveals the ease and multidimensional capability of the technique. An insight is given to the modern variations in the field such as coupling of IC with other techniques for the characterization of nuclear matrices, implementation of capillary IC in terms of miniaturization, and so on. The information presented herein will serve as a very useful resource for investigators in the field of characterization of nuclear materials.

The determination and separation of enantiomers is an interesting and important topic of research in various fields, e.g., biochemistry, food science, pharmaceutical industry, environment, etc. Although these compounds possess identical physicochemical properties, a pair of enantiomers often has different pharmacological, toxicological, and metabolic activities. For this reason, chiral discrimination by using chromatographic and electromigration techniques has become an urgent need in the pharmaceutical field. This review intends to offer the “state of the art” about the separation of chiral antifungal drugs and several related precursors by both liquid and gas chromatography, as well as electromigration methods. This overview is organized into two sections. The first one describes general considerations on chiral antifungal drugs. The second part deals with the main analytical methods for the enantiomeric discrimination of these drugs, including a brief description of chiral selectors and stationary phases. Moreover, many recent applications attesting the great interest of analytical chemists in the field of enantiomeric separation are presented.

Large volume injection (LVI) in gas chromatography (GC) and online liquid chromatography-gas chromatography (LC-GC) are useful techniques for analyzing the compounds present at very low concentrations in complex samples since they substantially increase the sensitivity of the analysis and simplify sample preparation. LVI avoids the need to concentrate the extract and even the extraction step itself by directly injecting the sample. In online LC-GC, the liquid chromatography (LC) step acts as the sample preparation and/or fractionation step. The main problem in both techniques is the selective elimination of the large volume of solvent without losing the analytes. The TOTAD (through oven transfer adsorption–desorption) interface, based on a widely modified PTV (programmed temperature vaporizer) injector, allows large volumes to be injected into the gas chromatograph using both nonpolar and polar solvents, including water. Consequently, online LC-GC can be carried out whether the LC step is in the normal phase or the reversed phase. Various methods for analyzing trace compounds in food and environmental samples have been developed for LVI and online LC-GC using the TOTAD interface. Such analysis methods require the optimization of several variables common to LVI and online LC-GC and specific variables involved in online LC-GC, which must be optimized by taking into account the nature of the analytes and the characteristics of the sample matrix. This article reviews how each of these variables affects the performance of the analysis.

Rice is the main staple food after wheat for more than half of the world’s population in Asia. Apart from carbohydrate source, rice is gaining significant interest in terms of functional foods owing to the presence of aromatic compounds that impart health benefits by lowering glycemic index and rich availability of dietary fibers. The demand for aromatic rice especially basmati rice is expanding in local and global markets as aroma is considered as the best quality and desirable trait among consumers. There are more than 500 volatile aromatic compounds (VACs) vouched for excellent aroma and flavor in cooked aromatic rice due to the presence of aromatic hydrocarbons, aldehydes, phenols, alcohols, ketones, and esters. The predominant VAC contributing to aroma is 2 acetyl-1-pyrroline, which is commonly found in aerial parts of the crop and deposits during seed maturation. So far, literature has been focused on reporting about aromatic compounds in rice but its extraction, characterization, and quantification using analytical techniques are limited. Hence, in the present review, extraction, characterization, and application of aromatic compound have been elucidated. These VACs can give a new way to food processing and beverage industry as bioflavor and bioaroma compounds that enhance value addition of beverages, food, and fermented products such as gluten-free rice breads. Furthermore, owing to their nutritional values these VACs can be used in biofortification that ultimately addresses the food nutrition security.

Allelopathy, a complex phenomenon has unveiled both stimulatory and inhibitory effects in plant processes that are mediated by the release of certain chemical compounds commonly known as allelochemicals. Allelochemicals, a form of bioactive secondary metabolites are produced by a diverse group of plants and microbes in response to biotic and abiotic stress. It ranges from a simple hydrocarbon to complex polycyclic aromatic compounds like phenol, flavonoids, tannins, steroids, amino acids, alkaloids and quinones. These plant bioactive compounds are released into the environment via decomposition, exudation, leaching and volatilization that play a significant role in regulating the intra-specific or inter-specific relations with counterparts. A wide variety of methods has been proposed for analyzing the basic mechanism and overall effect of allelochemicals. However, the lack of a reliable and effective method to identify their molecular mode of action and their modulation in the metabolic pathway still remains as a great challenge. From a commercial perspective, these allelochemicals are deemed to be better candidates for green natural herbicides and weedicides that are proven to be environment friendly, unlike synthetic chemicals. In order to pave a way for the economic viability of these chemicals, a basic understanding of their chemistry is inevitable. This review article is focused to give an in-depth understanding of metabolic pathways genes responsible for the elicitation/secretion and the adoption of a suitable downstream process and analytical techniques that can intensify the process.

With the progress of analysis technology and nanotechnology, colorimetric detection has become one of the research hotspots in the field of analytical chemistry. Compared with traditional detection methods, the colorimetric method has many advantages, such as high sensitivity, good selectivity, convenience and fast, as well as low cost. In recent years, metal nanoparticles have been introduced into colorimetry, making the research and application of colorimetry develop rapidly. In this work, we summarize the usual colorimetric detection methods based on metal nanoparticles-based nanozymes and their applications in the last five years. We hope that this work will help readers understand the mechanism and practical application value of nanozyme-based colorimetric biosensors. Meanwhile, this work may give some hints and references for future colorimetric detection research to promote the application and development of nanozyme-based colorimetry in biomedical and environmental analysis.

Antidepressants are a class of compounds widely used in clinical settings for the treatment of several diseases. In the last years there has been a considerable increase in their consumption, representing an important public health issue in several countries. Because they are substances with narrow therapeutic windows, and since they are capable of interacting with other classes of compounds, monitoring of these compounds is of relevance, minimizing the risk of medical interactions as well as side and toxic effects. In addition, understanding the extent of their use, their detection through routine toxicology tests and development of new methods for detection and monitoring is of extreme importance concerning public health, patient well-being, and implications in clinical and forensic situations. The main objective of this work is to perform a critical review on the biological samples used in the detection and quantification of antidepressants with special focus on the techniques for sample preparation.

Surface enhanced Raman is a powerful analytical tool with high sensitivity and unique specificity and promising applications in various branches of analytical chemistry. Despite the fabrication of ingenious enhancement substrate used in laboratory research, the development of simple, flexible, and cost-effective substrate is also great important for promoting the application of SERS in practical analysis. Recently, paper and filter membrane as support to fabricate flexible SERS substrates received considerable attentions. Paper-based SERS substrate has been reviewed but no summary on filter-based SERS substrate is available. Compared with paper, filter membrane has unique advantage in robust mechanics, diverse component, and tunable pore size. These characteristics endow the filter-based substrates great advantages for practical SERS analysis including simple and low-cost substrate preparation, high efficiency in preconcentration, separation and detection procedure. Therefore, filter-based substrates have shown great promise in SERS analysis in environment monitoring, food safety with high sensitivity and efficiency. As more and more work has been emerged, it is necessary to summarize the state of such a research topic. Here, the research on filter involved SERS analysis in the past eight years is summarized. A short introduction was presented to understand the background, and then the brief history of filter-based substrate is introduced. After that, the preparation of filter-based substrate and the role of filter are summarized. Then, the application of filter involved SERS substrate in analysis is presented. Finally, the challenges and perspective on this topic is discussed.