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Kaempferia galanga L. extract contains ethyl p-methoxycinnamate (EPMC) and ethyl cinnamate (EC), which have several pharmacological activities. EPMC and EC have been successfully isolated, but the %yield was low. Therefore, developing an isolation method to increase the %yield result of EPMC and EC is essential. The molecularly imprinted polymers have been applied to separate lot of active compounds from natural products with excellent results. MIP synthesis is usually performed using a single template with high selectivity for the target analyte but only detect single chemical compounds. Hence, this study synthesized multi-template molecularly imprinted polymers (MT-MIPs) for isolating EPMC and EC simultaneously using methacrylic acid as a functional monomer and ethylene glycol dimethacrylate or trimethyl propane trimethacrylate (TRIM) as a crosslinker. The study results indicate that MT-MIP produced with TRIM is more effective in separating EPMC and EC simultaneously in K. galanga L. extracts. However, the yields of EPMC and EC were still low. The yields of EPMC and EC in n-hexane extracts were 1.557 and 1.929%, with purity of 66.330 and 61.510%, respectively. Further research is necessary to determine the ideal functional monomer and its ratio to template molecules to obtain the excellent selectivity of the MT-MIPs used for simultaneously isolating EPMC and EC.

Background: Pigment Red 53 is a dangerous synthetic dye that is often added to cosmetics, even though its use in cosmetic products has been prohibited because of possible impacts on health. Faster and more sensitive detection of Pigment Red 53 is needed for onsite analysis to protect the community from illegal cosmetics that contain the dye. Indicator color charts are a kind of analytical method that can be used to detect Pigment Red 53 in cosmetic products, including lipstick, rouge, and eyeshadow. Such charts are practical, fast, and can be used for onsite analysis. Methods: In this study, an indicator for Pigment Red 53 detection was obtained through a reagent reaction that caused a specific color change. An indicator color chart was then produced by setting out in paper form the series of colors which resulted from the reaction of specific chemical reagents and Pigment Red 53 solutions at concentrations of 10, 20, 40, 60, 80, and 100 ppm. Results: The testing results showed that the indicator color chart may be used as an initial screening method for the detection of Pigment Red 53 in cosmetic products with a detectable minimum concentration of 10 ppm. Out of nine samples, only one (Eyeshadow 3) tested positive for Pigment Red 53. Further analysis was carried out on the indicator color chart and the results showed good agreement with TLC and UV–Vis spectrophotometry methods. Conclusion: The results reported in this paper demonstrate that the indicator color chart is a good prospective method for onsite analysis to detect Pigment Red 53 in cosmetic samples, with a lower detection limit compared to polymer‐based indicators. [ABSTRACT FROM AUTHOR]

Diazepam (DZP) is a benzodiazepine drug used as an anti-drug and sedative. It is often misused to induce or create euphoria in combination with other drugs (high or fly sensation) or administered alone. So far, screening for DZP abuse with sensitive analytical methods is needed, as its small concentrations make it difficult to detect. Increased sensitivity of the analytical method can be obtained by using a preparation method that selectively separates the analyte from the sample matrix. Molecularly imprinted polymer (MIP) is one of the preparation solutions with good selectivity, specificity, and sensitivity. MIP was made from DZP as a template, itaconic acid, and ethylene glycol dimethacrylate in a composition of 1:4:20. MIP was made by precipitation polymerisation to obtain microsphere polymer type. MIP had a binding capacity value of 0.0557 mg/g and followed the Freundlich isotherm. Application of the microsphere MIP on spiked blood serum resulted in a recovery of 105.63 ± 1.0% for MIP compared to 21.28 ± 0.4% for non-imprinted polymer, with the imprinting factor value reaching 4.96. Hence, MIP DZP with itaconic acid as a functional monomer and propanol as a porogen, fabricated by the precipitation polymerisation method, is a promising sorbent for DZP extraction in biological fluids.

In recent years, discovering new drug candidates has become a top priority in research. Natural products have proven to be a promising source for such discoveries as many researchers have successfully isolated bioactive compounds with various activities that show potential as drug candidates. Among these compounds, phenolic compounds have been frequently isolated due to their many biological activities, including their role as antioxidants, making them candidates for treating diseases related to oxidative stress. The isolation method is essential, and researchers have sought to find effective procedures that maximize the purity and yield of bioactive compounds. This review aims to provide information on the isolation or separation methods for phenolic compounds with antioxidant activities using column chromatography, medium-pressure liquid chromatography, high-performance liquid chromatography, counter-current chromatography, hydrophilic interaction chromatography, supercritical fluid chromatography, molecularly imprinted technologies, and high-performance thin layer chromatography. For isolation or purification, the molecularly imprinted technologies represent a more accessible and more efficient procedure because they can be applied directly to the extract to reduce the complicated isolation process. However, it still requires further development and refinement. [ABSTRACT FROM AUTHOR]

During the last decade, advances have been made in nanotechnology using nanomaterials, leading to improvements in their performance. Gold nanoparticles (AuNPs) have been widely used in the field of sensor analysis and are also combined with certain materials to obtain the desired characteristics. AuNPs are commonly used as colorimetric sensors in detection methods. In developing an ideal sensor, there are certain characteristics that must be met such as selectivity, sensitivity, accuracy, precision, and linearity, among others. Various methods for the synthesis of AuNPs and conjugation with other components have been carried out in order to obtain good characteristics for their application. AuNPs can be applied in the detection of both heavy metals and biological molecules. This review aimed at observing the role of AuNPs in its application. The synthesis of AuNPs for sensors will also be revealed, along with their characteristics suitable for this role. In the application method, the size and shape of the particles must be considered. AuNPs used in heavy metal detection have a particle size of around 15–50 nm; in the detection of biological molecules, the particle size of AuNPs used is 6–35 nm whereas in pharmaceutical compounds for cancer treatment and the detection of other drugs, the particle size used is 12–30 nm. The particle sizes did not correlate with the type of molecules regardless of whether it was a heavy metal, biological molecule, or pharmaceutical compound but depended on the properties of the molecule itself. In general, the best morphology for application in the detection process is a spherical shape to obtain good sensitivity and selectivity based on previous studies. Functionalization of AuNPs with conjugates/receptors can be carried out to increase the stability, sensitivity, selectivity, solubility, and plays a role in detecting biological compounds through conjugating AuNPs with biological molecules. [ABSTRACT FROM AUTHOR]

The presence of drug residues in food products has become a growing concern because of the adverse health risks and regulatory implications. Drug residues in food refer to the presence of pharmaceutical compounds or their metabolites in products such as meat, fish, eggs, poultry and ready-to-eat foods, which are intended for human consumption. These residues can come from the use of drugs in the field of veterinary medicine, such as antibiotics, antiparasitic agents, growth promoters and other veterinary drugs given to livestock and aquaculture with the aim of providing them as prophylaxis, therapy and for promoting growth. Various analytical techniques are used for this purpose to control the maximum residue limit. Compliance with the maximum residue limit is very important for food manufacturers according to the Food and Drug Administration (FDA) or European Union (EU) regulations. Effective monitoring and control of drug residues in food requires continuous advances in analytical techniques. Few studies have been reviewed on sample extraction and preparation techniques as well as challenges and future directions for the determination of veterinary drug residues in food. This current review focuses on the overview of regulations, classifications and types of food, as well as the latest analytical methods that have been used in recent years (2020–2023) for the determination of drug residues in food so that appropriate methods and accurate results can be used. The results show that chromatography is still a widely used technique for the determination of drug residue in food. Other approaches have been developed including immunoassay, biosensors, electrophoresis and molecular-based methods. This review provides a new development method that has been used to control veterinary drug residue limit in food. [ABSTRACT FROM AUTHOR]

Hg2+ is one of the most dangerous pollutants that can cause damage to organs and the immune system. The common detection methods of Hg2+ require sophisticated instrumentation and a long time for analysis. The purpose of this study was to develop a sensor for the detection of Hg2+ using filter paper immobilized by gold nanoparticles (AuNPs) conjugated with cyanuric acid (CA). The clear color change from pink to bluish purple is the response of the CA-AuNPs filter paper sensor to exposure to Hg2+. Detection can be observed visually with the naked eye and/or with imageJ software; the detection limit is 0.05 µM. The colorimetric response of the sensor was also selective towards Hg2+ after testing with different metal ions. In addition, the response from the sensor was also consistent for lake water samples spiked with Hg2+. The results of this research provide a promising basic technology for the development of sensors that are affordable, fast, portable, and easy to use for the detection and monitoring of Hg2+ levels in water. [ABSTRACT FROM AUTHOR]

Educational activities on the use of plant pigments as acid-base indicators in acid-base titrations and how to extract them have been carried out at a high school located in Babakan Village, Ciwaringin District, Cirebon Regency with a pre-test stage to determine the baseline knowledge of students regarding acid-base indicators and pigments, followed by education and ended with a post test using the same material as the pre-test. The pre-test was conducted to measure high school knowledge regarding pigments, extraction methods and their use as acid-base indicators by giving 4 basic questions, to 136 participants. Then continued with the presentation of material using the lecture method using Powerpoint slides accompanied by a demo in the form of videos and questions and answers, after that followed by a post test using the same questions, where 55.88% experienced an increase, 43.38% experienced fixed results, and 0.7% which decreased. The results of the analysis of the results of the post-test and questionnaires after the activity showed that the students were able to adapt to the learning system of the PPM activity implementation team, which means that students were able to develop their knowledge, learn from previous experiences (pre-test) as well as additional information from the material provided by the team. PPM implementers during education and discussions. [ABSTRACT FROM AUTHOR]

Dexamethasone is a chemical drug that is usually added to herbal medicine because of its effects on pain relief, arthritis, anti-inflammation, etc. Chemical drugs should not be used in herbal medicine because uncontrolled consumption causes some side effects. A polymer-based indicator was developed to detect dexamethasone in herbal medicine samples in a fast and simple way compared to instrumental analysis. The indicator strips were made by mixing polymethylmethacrylate (PMMA) polymer with sulfuric acid (H2SO4) as a reagent. When reacting with dexamethasone, H2SO4 can cause the color to change into a specific light pink-purple color. Indicator strips were prepared with a composition of 5% PMMA in ethyl acetate:H2SO4 (9:1) by using the reagent blending method. The indicator strips showed a pink-purple color when they were applied to a positive herb containing dexamethasone. The indicator strips could selectively detect dexamethasone rather than other active substances that are often found in herbal medicine. These indicator strips could also detect dexamethasone with the smallest detection limit of 13.13 ppm, and they had a stability of up to 36 days. Detection was carried out in real samples to show the performance of the indicator strips. The result showed that of nine samples, five were confirmed to contain dexamethasone. These results showed a good agreement with the results of thin-layer chromatography (TLC) and high-performance liquid chromatography (HPLC). According to the result, these indicator strips provide a simple and applicable method for on-site analysis to detect dexamethasone in samples. [ABSTRACT FROM AUTHOR]

Natural pigments occur in plants as secondary metabolites and have been used as safe colourants in food. Studies have reported that their unstable colour intensity might be related to metal ion interaction, which leads to the formation of metal–pigment complexes. This underlines the need for further investigations on the use of natural pigments in metal detection using colorimetric methods, since metals are important elements and can be hazardous when present in large amounts. This review aimed to discuss the use of natural pigments (mainly betalains, anthocyanins, curcuminoids, carotenoids, and chlorophyll) as reagents for portable metal detection based on their limits of detection, to determine which pigment is best for certain metals. Colorimetric-related articles over the last decade were gathered, including those involving methodological modifications, sensor developments, and a general overview. When considering sensitivity and portability, the results revealed that betalains are best applied for copper, using a smartphone-assisted sensor; curcuminoids are best applied for lead, using a curcumin nanofiber; and anthocyanin is best applied for mercury, using anthocyanin hydrogel. This provides a new perspective on the use of colour instability for the detection of metals with modern sensor developments. In addition, a coloured sheet representing metal concentrations may be useful as a standard to support on-site detection with trials on masking agents to improve selectivity. [ABSTRACT FROM AUTHOR]

Pigment red 53 is a synthetic dye that has been banned in cosmetic products due to the possibility of causing blood disorders and spleen sarcoma. The indicator strip employs qualitative analysis methods that are simpler, easier, and quicker than an instrumental analysis. The indicator strip is made of a polymethylmethacrylate (PMMA) and polystyrene (PS) mixture using a reagent blending method with specific reagents of concentrated sulfuric acid (H2SO4), concentrated hydrochloric acid (HCl), or 10% sodium hydroxide (NaOH). Pigment red 53 detections with an indicator strip are based on the occurrence of a specific color change reaction between the reagent and pigment red 53 through sulfonation with concentrated H2SO4, neutralization with 10% NaOH, and reaction of pigment red 53's azo group with concentrated HCl. PMMA was made with a concentration of 5% (w/t), and mixtures of PS:PMMA 1:2, 1:3, and 1:4 had solvent-to-specific reagent ratios of 60:40, 80:20, and 90:10. The best results were obtained for PMMA-H2SO4 (90:10), PMMA-HCl (80:20), and PMMA-NaOH (60:40), with the lowest detection limits equaling 20 ppm, 50 ppm, and 20 ppm, respectively. Meanwhile, the best PS:PMMA (1:4)-based indicator strips obtained were PS:PMMA-H2SO4 (90:10), PS:PMMA-HCl (80:20), and PS:PMMA-NaOH (60:40), with the lowest detection limits being 20 ppm, 10 ppm, and 20 ppm, respectively. All indicator strips are stable for at least 80 days. Indicator strips can be used as a simple and applicable method for detecting pigment red 53 in cosmetic products with a good performance. [ABSTRACT FROM AUTHOR]

Chemical drugs have been added to some of the traditional herbal medicine to enhance the therapeutic effect. One of them is dexamethasone which is added in herbal pain relief. To determine the content of dexamethasone in herbal medicine, a quantitative analytical method was developed with the reaction of the formation of a dexamethasone-hydroxylamine complex with fluoranil which was measured by UV-Vis spectrophotometry. Under optimized conditions, the performance of this system to analyze dexamethasone exhibited a good analytical response. The correlation coefficient was (R2) of 0.9965 from a concentration of 1–40 g/mL, LOD, and LOQ of 0.21 μg/mL and 0.64 μg/mL, % recovery for concentrations of 80%,100%, and 120%, are 100.14% ± 0.58; 98.35% ± 1.19; and 99.00% ± 1.18, respectively; and %RSD is 0.75%. The sixteen herbal medicine samples were analyzed to confirm the application of this method. The result showed six samples confirmed containing dexamethasone with levels ranging from 7.44 to 21.61 μg/mL and confirmed with HPLC data. The UV-Vis spectrophotometry method is simple and effective for dexamethasone analysis in herbal medicine. [ABSTRACT FROM AUTHOR]

The general public uses cosmetics daily. Cosmetic products contain substances (ingredients) with various functions, from skincare to enhancing appearance, as well as ingredients that preserve the cosmetic products. Some cosmetic ingredients are prohibited or restricted in certain geographical regions, such as the European Union and the United States of America, due to their potential to cause adverse effects such as cancer, birth defects, and/or developmental and reproductive disorders. However, the ingredients may be used in other regions, and, hence, the monitoring of the cosmetic ingredients actually used is important to ensure the safety of cosmetic products. This review provides an overview of recent analytical methods that have been developed for detecting certain ingredients that are restricted or prohibited by the U.S. Food and Drug Administration (FDA) and/or EU legislation on cosmetic products. [ABSTRACT FROM AUTHOR]

The paper-based device for allopurinol detection was developed by an enzymatic reaction. The concept is that allopurinol will act by blocking the xanthine oxidase enzyme to produce uric acid and H2O2, resulting in a color change from purple to pale purple until it is colorless. The concept was proofed by spectrophotometry and was applied in four types of filter paper including Whatman Qualitative No. 1, No. 4, and No. 6, and Whatman 1 chromatography. The application of this system was observed using ImageJ analysis. The performance of the paper reveals that each Whatman has different characteristics with LOD and LOQ range were 1.62-2.24 ppm and 4.91-6.80 ppm, respectively. The stability study shows that all of the paper was stable for 3 days both at room temperature (around 24°C-26°C) and 4°C. The presence of another drug like paracetamol did not prevent allopurinol detection. The real traditional medicine sample was also analyzed to confirm the applicability of this paper, and the result showed good agreement with spectrophotometry data. [ABSTRACT FROM AUTHOR]

Diazepam is a benzodiazepine that has the potency to be misused because it is effective, easily obtained, and inexpensive. The misuse of diazepam is to replace illegal drugs and be a sedative. Separation of diazepam is needed to detect possible drug abuse and to monitor drug levels in blood to ensure the effectiveness of the drug. This study was conducted to obtain a molecularly imprinted solid-phase extraction (MI-SPE) sorbent to separate diazepam from serum samples. This work started at the synthesis stage with the bulk polymerization method, using methyl methacrylate and acrylamide as functional monomers, diazepam as a template, and ethylene glycol dimethacrylate as a crosslinker. The polymer obtained was identified by its adsorption capacity and packaged into a solid-phase extraction (SPE) cartridge, and the extraction conditions were optimized. The optimization results were then used to extract diazepam from the serum sample. The test results showed that the adsorption ability of the molecularly imprinted polymer (MIP) with the functional monomer, methyl methacrylate, was 63.98 ± 0.1%, which is higher than that of the acrylamide MIP monomer, with a value of 43.27 ± 0.1%. The MIP sorbent of methyl methacrylate was applied to the SPE with 200 mg of polymer in a 3 mL cartridge. Diazepam added to serum samples were then passed through the MIP-SPE producing a percent recovery value of 95.31 ± 1.1% for MIP and 60.83 ± 0.3% for nonimprinted polymer (NIP). The results showed that the MI-SPE sorbent made from the monomer methyl methacrylate gave higher extraction recovery results than acrylamide, and it could be used for extracting diazepam from serum samples with or without other substances. [ABSTRACT FROM AUTHOR]

Atenolol is one of the beta-1 blocker drugs that is misused by athletes to increase their performance during competition. Therefore, it is important to analyze atenolol levels in blood selectively. The preparation method that can be used in separating atenolol in sample is molecular imprinting solid-phase extraction (MI-SPE) because it has good selectivity and sensitivity. This study aims to examine the characteristics and analytical performance of imprinted polymers synthesized from functional monomer methyl methacrylate. The stages of this study include the determination of association constants, synthesis of sorbent MI-SPE atenolol using the bulk polymerization method, and precipitation with atenolol as the template, methyl methacrylate as the functional monomer, and propanol as the porogen. The template was extracted from a polymer, and then, the adsorption ability, capacity, and selectivity of MI-SPE and finally the application of the best MI-SPE to spiked serum samples were determined. MI-SPE was also characterized by using Fourier-transform instrument infrared (FTIR) and scanning electron microscope (SEM). The result of characterization with FTIR and SEM showed that MIP made by the precipitation polymerization method was completely polymerized, more porous, and produced smaller particle size with an average value of 0.274 μm. It had better analytic performances than MIP made by bulk polymerization, with affinity value 0.3607 mg/g and homogeneity value 1.3246, and good selectivity toward atenolol with imprinting factor value 22.519. Application of MI-SPE to spiked serum samples has an excellent recovery percentage of 95.46% over 0% for the nonimprinting one. Based on the result of study, MIP made by precipitation polymerization could be used to extract atenolol on serum samples toward drug analysis. [ABSTRACT FROM AUTHOR]

Gartanin is one of derivated xanthone compound in the pericarp of the mangosteen fruit. Gartanin has several pharmacological activities such as antifungal, antioxidant, anticancer bladder, and anticancer lung. The aims of this research are to analyze gartanin in the extract of mangosteen pericarp that combines with partial least squares multivariate calibration to determine the correlation between the concentration of gartanin in the extract of mangosteen pericarp that analyzes by HPLC and by FTIR spectroscopy. The wavenumbers region of 4000-650 cm-1 was selected for prediction of gartanin in the extracts. The correlation between actual values of gartanin determined by HPLC and FTIR predicted values using FTIR spectroscopy combined with PLS. The results showR2 values for each region are 0.988 and 0.981 for Subang and Tasikmalaya, respectively and for cross-validation values R2 = 0.838, PRESS = 0.0068898, and RMSEC = 0.0003192 for Subang and R2 = 0.969, PRESS = 0.0007422, dan RMSEC = 0.0002151 for Tasikmalaya. The high value of R2 and low value of RMSEC indicated the high accuracy and precision of FTIR spectroscopy for quantification of gartanin in the extracts. These results indicated that FTIR spectroscopy combined with PLS is an alternative technique for determination of gartanin in the extract of mangosteen pericarp (Garcinia mangostana L.). [ABSTRACT FROM AUTHOR]

Traditional herbal medicine in Indonesia is still in great demand and popular in society. The Indonesian government regulations state that herbal medicine should not contain chemical drug due to the toxic effect of uncontrolled consumption. Allopurinol is one of the drugs commonly added to herbal medicine for the treatment of chronic gout. Paper-based analytical device is one of the latest forms of analysis that has been widely used for the identification of chemical elements, environmental contamination, bacteria, and many more. In this study, experiments were conducted using Whatman filter paper No. 1, No. 2, and No. 4 and Whatman chromatography as a paper, and 9 colorimetric reagents were tested for allopurinol detection in herbal medicine. There were 5 specific reagents that reacted positively with allopurinol and only 3 reagents that can be applied to the paper, that is, Folin-Ciocalteu, Tollens, and p-DAB reagent. The results of the optimization show that the most optimal immersion time was 60 minutes with a drying time of 30 minutes at 50°C. Each filter paper has different characteristic; however, there was no significant difference when all of the papers were used as PAD for allopurinol detection. [ABSTRACT FROM AUTHOR]

Objective: Atenolol is one of beta-blocker are prohibited as doping based on World Anti-Doping Agency (WADA). The purpose of this study was to the synthesis of molecular imprinted polymer (MIP) for extraction of atenolol from the sample. Method: This research compared the two of the method, bulk and precipitation polymerization. The MIP was successfully prepared from methacrylic acid as a functional monomer, ethyleneglycoldimethacrylate as a crosslinker, benzoyl peroxide as an initiator, butanol as a porogenic solvent with atenolol as a template molecule. Result: The result showed that the bulk polymerization method produces sorbents that have good adsorption capacity and small particle compare to the precipitation polymerization. Both methods were selective for atenolol. Conclusion: Generally, the MIP solid phase extraction is an alternative method for extraction atenolol from the sample. [ABSTRACT FROM AUTHOR]

Generally, regulation states that herbal medicines are remedies containing plants or preparation of plants as active ingredients only. Paracetamol is one of the drugs that is frequently added in herbal medicine to enhance the effect as an analgesic. The government regulation disallows chemical drugs contained in herbal medicine due to the toxic effect of uncontrolled consumption. On this study, the optical sensor membrane from polymer poly(methyl methacrylate) (PMMA) was synthesized by phase inversion method and was used to detect paracetamol in herbal medicine. PMMA was made in three different concentrations 5%, 7.5%, and 10% and was mixed with ferric chloride (FeCl3), Folin-Ciocalteu, and Nessler reagent as specific colorimetric reagents for paracetamol detection, with a ratio of solvent:reagent was 6:4; 7:3; and 8:2. The result of the experiment shows that PMMA-FeCl3 7.5% (7:3), PMMA-Folin 5% (6:4), and PMMA-Nessler 5% (6:4) give the best performance for paracetamol detection. Real herbal medicine samples were analyzed to confirm the practical application of this sensor, and the result shows good agreement with UV-Vis data. The results show that optical sensor membrane which has been developed can be used as new detection method of paracetamol for community application. [ABSTRACT FROM AUTHOR]

Herbal medicine has become popular in recent years as an alternative medicine. The problem arises when herbal medicines contain an undeclared synthetic drug that is illegally added, since it is a natural product that does not contain any chemical drugs due to the potential cause of harmful effects. Supervision of herbal medicines is important to ensure that these herbal medicines are still safe to use. Thus, developing a reliable analytical technique for the determination of adulterated drugs in herbal medicine is gaining interest. This review aims to provide a recent analytical method that has been used within the past 5 years (2016–2021) for the determination of chemical adulterants in herbal medicine. [ABSTRACT FROM AUTHOR]

Codeine is derived from morphine, an opioid analgesic, and has weaker analgesic and sedative effects than the parent molecule. This weak opioid is commonly used in combination with other drugs for over-the-counter cough relief medication. Due to the psychoactive properties of opioid drugs, the easily obtained codeine often becomes subject to misuse. Codeine misuse has emerged as a concerning public health issue due to its associated adverse effects such as headache, nausea, vomiting, and hemorrhage. Thus, it is very important to develop reliable analytical techniques to detect codeine for both quality control of pharmaceutical formulations and identifying drug misuse in the community. This review aims to provide critical outlooks on analytical methods applicable to the determination of codeine. [ABSTRACT FROM AUTHOR]

The interaction of three cationic porphyrins—meso-tetrakis (N-methylpyridinium-4-yl) porphyrin (TMPyP), meso-tetrakis (1,3-dimethylimidazolium-2-yl) porphyrin (TDMImP), and meso-tetrakis (1,2-dimethylpyrazolium-4-yl) porphyrin (TDMPzP)—with five heavy metals was studied computationally, and binding constants were calculated based on data obtained by an experimental method and compared. The reactivity and stability of their complexes formed with lead, cadmium, mercury, tin, and arsenic ions were observed in DFT global chemical reactivity descriptors: the electronic chemical potential (µ), chemical hardness (η), and electrophilicity (ω). The results show that M-TDMPzP has higher chemical hardness and lower electrophilicity compared to M-TMPyP and M-TDMImP, indicating the reaction of TDMPzP with metals will form a more stable complex. Specifically, Cd-TDMPzP complexes can stabilize the system, with a lower energy and electronic chemical potential, higher chemical hardness, smaller electrophilicity, and higher binding constant value compared to Pb-TDMPzP and Hg-TDMPzP. This result suggests that the interaction of the Cd2+ ion with TDMPzP will produce a stable complex. [ABSTRACT FROM AUTHOR]

The use of paper microfluidics to perform chemical measurements for various analytical applications has gained interest over the last decade. One of the growing applications of these platforms is for the qualitative and quantitative determination of drugs. The low cost and self-pumping ability of paper microfluidics are attractive for developing analytical tools capable of on-site drug screening. This review aims to present the unique features of microfluidic paper-based analytical devices (μPADs) that offer advantages to pharmaceutical analysis and evaluate the state-of-the-art technologies and applications of the platform for drug analysis in research and real-world settings. The current challenges and potential future directions of the field are also highlighted. Image of test cards is adapted with permission from A.A. Weaver, H. Reiser, T. Barstis, M. Benvenuti, D. Ghosh, M. Hunckler, B. Joy, L. Koenig, K. Raddell, M. Lieberman, Paper analytical devices for fast field screening of beta lactam antibiotics and antituberculosis pharmaceuticals, Anal. Chem. 85 (2013) 6453–6460. (Copyright 2013 American Chemical Society). Image 1 • A critical review of the emerging use of paper-based devices/μPADs for drug analysis. • Attractive features of μPADs relevant to drug analysis are discussed. • State-of-the-art fabrication methods and detection motifs applicable to drugs. • Applications in discovery, quality control, and tests of drugs in various matrices. • Highlight of challenges and future outlooks of μPADs for drug analysis. [ABSTRACT FROM AUTHOR]