Direct determination of propranolol in urine by spectrofluorimetry with the aid of second order advantage

Mercury (II) sensing using a simple turn-on fluorescent graphene oxide based aptasensor in serum and water samples

A simple, highly sensitive, and selective fluorometric aptasensing platform based on aptamer and graphene oxide (GO) is proposed for the determination of mercury (II) ion (Hg2+). In the designed assay, two aptamer probes, a carboxy-fluorescein (FAM) labeled aptamer (aptamer A) and its complementary (aptamer B) with partial complement containing several mismatches and GO as the quencher were used. In the absence of Hg2+, both A and B aptamers were adsorbed on the surface of GO by π-π-stacking, leading to fluorescence quenching of FAM due to fluorescence resonance energy transfer (FRET). Upon exposure to Hg2+, the A and B aptamer strands bind Hg2+ and form T-Hg2+-T complexes, leading to the formation of a stable double-stranded aptamer. The double-stranded aptamer is detached from the GO surface, resulting in the recovery of FAM fluorescence. The fluorescence intensity (FI) of the developed sensor was correlated with the Hg2+ concentration under optimized experimental conditions in two wide linear ranges, even in the presence of 10 divalent cations as interferences. The linear ranges were obtained from 200.0 to 900.0 fM and 5.0 to 33.0 pM, a limit of detection (LOD) of 106.0 fM, and a limit of quantification (LOQ) of 321.3 fM. The concentration of Hg2+ was determined in five real samples containing three water and two serum samples, using spiking and standard addition methods and the results were compared with the spiked amounts and atomic absorption (AAS) as standard method respectively, with acceptable recoveries. Furthermore, in the standard addition method, to overcome the effects of matrix influence of real samples in quantitative predictions, the excitation-emission matrix (EEM) data for samples was simultaneously analyzed by multivariate curve resolution with alternating least squares (MCR-ALS) as a second-order standard addition method (SOSAM).

Manufacturing of a Sensitive and Selective Optical Sensor Based on Molecularly Imprinted Polymers and Green Carbon Dots Synthesized from Cedrus Plant for Trace Analysis of Propranolol

In this article, a new optical sensor was developed using a molecularly imprinted polymers layer coated with new green carbon dots (CDs) for the determination of propranolol. First, the CDs were synthesized for the first time from Cedrus plant through the hydrothermal method. Then, a nanolayer molecularly imprinted polymer (MIP) was applied on the CDs (MIP-CDs) in the presence of propranolol as a template using a reverse microemulsion technique. Afterward, propranolol was removed from MIP-CDs nanocomposites using a mixture of ethanol and acetonitrile, and the obtained nanocomposite was used as a fluorescence sensor for propranolol determination. Under the optimal conditions, the sensor response was linear in the range of 0.8 - 65.0 nmol L^-1 with a detection limit of 0.2 nmol L^-1. The results confirmed that the sensor has some advantages such as cost-effectiveness, rapid response, high sensitivity and selectivity for propranolol determination.

Propranolol

Propranolol is a noncardioselective β-blocker. It is reported to have membrane-stabilizing properties, but it does not own intrinsic sympathomimetic activity. Propranolol hydrochloride is used to control hypertension, pheochromocytoma, myocardial infarction, cardiac arrhythmias, angina pectoris, and hypertrophic cardiomyopathy. It is also used to control symptoms of sympathetic overactivity in the management of hyperthyroidism, anxiety disorders, and tremor. Other indications cover the prophylaxis of migraine and of upper gastrointestinal bleeding in patients with portal hypertension. This study provides a detailed, comprehensive profile of propranolol, including formulas, elemental analysis, and the appearance of the drug. In addition, the synthesis of the drug is described. The chapter covers the physicochemical properties, including X-ray powder diffraction, pK, solubility, melting point, and procedures of analysis (spectroscopic, electrochemical, and chromatographic). In-depth pharmacology is also presented (pharmacological actions, therapeutic dosing, uses, Interactions, and adverse effects and precautions). More than 60 references are given as a proof of the abovementioned studies.

Second-order data obtained by beta-cyclodextrin complexes: a novel approach for multicomponent analysis with three-way multivariate calibration methods

This research reports the first application of β-cyclodextrin (β-CD) complexes as a new method for generation of three way data, combined with second-order calibration methods for quantification of a binary mixture of caffeic (CA) and vanillic (VA) acids, as model compounds in fruit juices samples. At first, the basic experimental parameters affecting the formation of inclusion complexes between target analytes and β-CD were investigated and optimized. Then under the optimum conditions, parallel factor analysis (PARAFAC) and bilinear least squares/residual bilinearization (BLLS/RBL) were applied for deconvolution of trilinear data to get spectral and concentration profiles of CA and VA as a function of β-CD concentrations. Due to severe concentration profile overlapping between CA and VA in β-CD concentration dimension, PARAFAC could not be successfully applied to the studied samples. So, BLLS/RBL performed better than PARAFAC. The resolution of the model compounds was possible due to differences in the spectral absorbance changes of the β-CD complexes signals of the investigated analytes, opening a new approach for second-order data generation. The proposed method was validated by comparison with a reference method based on high-performance liquid chromatography photodiode array detection (HPLC-PDA), and no significant differences were found between the reference values and the ones obtained with the proposed method. Such a chemometrics-based protocol may be a very promising tool for more analytical applications in real samples monitoring, due to its advantages of simplicity, rapidity, accuracy, sufficient spectral resolution and concentration prediction even in the presence of unknown interferents.

Dispersive liquid–liquid microextraction based on solidification of floating organic droplet followed by spectrofluorimetry for determination of carvedilol in human plasma

Background: Simple, chip and rapid analytical methods are required in biomedical analysis laboratories to support therapeutic drug monitoring units in hospitals. The present work aimed to provide such a method for quantitative determination of carvedilol in plasma samples. Results: A new, simple, precise and efficient method was developed for the determination of carvedilol in human plasma using a dispersive liquid–liquid microextraction based on solidification of floating organic droplet, followed by spectrofluorimetry method. Some important parameters such as types and volumes of extraction and disperser solvents, pH, salt effect and sample volume were optimized. Under the optimized experimental conditions, the method provided a linear range of 40 to 300 ng ml-1, with a correlation coefficient of 0.996. The limit of detection, lower limit of quantification and upper limit of quantification were 18, 40 and 300 ng ml-1, respectively. The found recovery was from 98.2 to 102.2%, the mean intra- and inter-day precisions were 8.3 and 6.4%, respectively. The relative error for accuracy varied from 0.4 to 2.2%. The short-term temperature and freeze–thaw stability studies showed that carvedilol in human plasma was stable for sample preparation and analysis after storage. Conclusion: The proposed method provided reasonable acceptable results and could be used for therapeutic monitoring of carvedilol.

Detection and quantitation of β-blockers in plasma and urine

β-blockers are a class of antihypertensive drugs that are used for the management of cardiac arrhythmias, cardioprotection after myocardial infarction (heart attack) and hypertension. They have revolutionized the medical management of angina pectoris and are recommended as first-line agents by national and international guidelines. Although β-blockers are still the cornerstone for the treatment of heart failure, some of the drugs in this category are prohibited in several sports requiring vehicle control and bodily movements as they reduce heart rate and tremors, and improve performance. As a result, urine analysis of β-blockers is mandatory in doping control and toxicological screening. The determination of plasma levels of β-blockers helps to ensure noncompliance in patients with persistent hypertonia to confirm the diagnosis of β-blocker poisoning and for therapeutic drug monitoring. This review provides a comprehensive account of various analytical methods developed for detection and quantitation of β-blockers in plasma and urine.