Ion-association Complex Research Articles

Synthesis of 4-Amino-N-[2 (diethylamino)Ethyl]Benzamide Tetraphenylborate Ion-Associate Complex: Characterization, Antibacterial and Computational Study.

The 4-amino-N-[2 (diethylamino) ethyl] benzamide (procainamide)-tetraphenylborate complex was synthesized by reacting sodium tetraphenyl borate with 4-amino-N-[2 (diethylamino) ethyl] benzamide, chloride salt, and procainamide in deionized water at room temperature through an ion-associate reaction (green chemistry) at room temperature, and characterized by several physicochemical methods. The formation of ion-associate complex between bio-active molecules and/or organic molecules is crucial to comprehending the relationships between bioactive molecules and receptor interactions. The solid complex was characterized by infrared spectra, NMR, elemental analysis, and mass spectrometry, indicating the formation of ion-associate or ion-pair complex. The complex under study was examined for antibacterial activity. The ground state electronic characteristics of the S1 and S2 complex configurations were computed using the density functional theory (DFT) approach, using B3LYP level 6-311 G(d,p) basis sets. R2 = 0.9765 and 0.9556, respectively, indicate a strong correlation between the observed and theoretical 1H-NMR, and the relative error of vibrational frequencies for both configurations was acceptable, as well. HOMO and LUMO frontier molecular orbitals and molecular electrostatics using the optimized were used to obtain a potential map of the chemical. The n → π* UV absorption peak of the UV cutoff edge was detected for both configurations of the complex. Spectroscopic methods were structures used to characterize the structure (FT-IR and 1HNMR). In the ground state, DFT/B3LYP/6-311G(d,p) basis sets were used to determine the electrical and geometric properties of the S1 and S2 configurations of the title complex. Comparing the observed and calculated values for the S1 and S2 forms, the HOMO-LUMO energy gap of compounds was 3182 and 3231 eV, respectively. The small energy gap between HOMO and LUMO indicated that the compound was stable. In addition, the MEP reveals that positive potential sites were around the PR molecule, whereas negative potential sites were surrounding the TPB site of atoms. The UV absorption of both arrangements is comparable to the experimental UV spectrum.

Application of reactive dyes in Validation of favipiravir from pharmaceutical dosages

Simple sensitive and accurate ion pair complex formation with reactive dyes, extractive spectrophotometric methods have developed for the estimation of favipiravir in pharmaceutical dosage form. The methods are based on the formation of ion paired coloured complexes by the drug with reactive dyes like Congo red, eriochrome black T and methyl orange in acidic medium. The ion associated complexes were formed and quantitatively extracted under the experimental condition in chloroform. The absorbance values were measured at 490 nm, 500 nm, and 430 nm respectively. The proposed methods were validated statistically. Recoveries of methods were carried out by standard addition method. The linearity was found to be 5.0-30.0 μg/ml, 5 -12 μg/ml, and 2-20 μg/ml for methods respectively. The low values of standard deviation and percentage RSD indicate high precision of methods. Hence these methods are useful for routine estimation of favipiravir in pharmaceutical dosages.

Use of sodium tetraphenylborate reagent for conductometric titration of Amlodipine Besylate in pure and pharmaceutical forms

Simple, accurate and reliable conductometric method for the quantitative determination of Amlodipine Besylate (AML) in pure form and pharmaceutical formulations using sodium tetraphenylborate (TPB) in aqueous solution at 20°C has been described. The method is based on the formation of ion association complex of cation coming from the cited drug with tetraphenylborate anion and the conductance of the solution is measured as a function of the volume of titrant. Many experimental conditions were evaluated. The described procedure allowed the determination of AML in double distilled water in the range of 0.200-1.000mM. The accuracy of the method is indicated by the excellent recovery 98.60-101.40%, and the precision is supported by the low relative standard deviation < 4.74 %. The method was further applied successively to pharmaceutical formulations with no interference from the excipients, the results obtained were compared statistically with those obtained by the official method and showed no significant differences regarding accuracy and precision.

Use of sodium tetraphenylborate reagent for conductometric titration of Amlodipine Besylate in pure and pharmaceutical forms

Simple, accurate and reliable conductometric method for the quantitative determination of Amlodipine Besylate (AML) in pure form and pharmaceutical formulations using sodium tetraphenylborate (TPB) in aqueous solution at 20°C has been described. The method is based on the formation of ion association complex of cation coming from the cited drug with tetraphenylborate anion and the conductance of the solution is measured as a function of the volume of titrant. Many experimental conditions were evaluated. The described procedure allowed the determination of AML in double distilled water in the range of 0.200-1.000mM. The accuracy of the method is indicated by the excellent recovery 98.60-101.40%, and the precision is supported by the low relative standard deviation < 4.74 %. The method was further applied successively to pharmaceutical formulations with no interference from the excipients, the results obtained were compared statistically with those obtained by the official method and showed no significant differences regarding accuracy and precision.

Estimation of terbinafine HCL by spectophotometric analysis with Tpooo, Nb12br and WFB

One simple and sensitive procedure (simple spectrophotometric method) for the assay of drug Terbinafine HCl in pure form and formulations. This method involves the formation of ion-association complex between TRB and the TPOOO, NB12BR and WFB. In order to establish the optimum conditions necessary for rapid and quantitative formation of coloured product with maximum stability and sensitivity, the author performed experiments by measuring the absorbance at λmax 480nm,420nm and580nm of respective series of solutions, varying one and fixing the other parameters in each case such as type, volume and concentration of acid, organic solvent used for extraction, ratio of organic phase to aqueous phase during extraction, shaking time and temperature. The variable parameters were optimized. The results were statistically validated.

Derivatization reaction-based multi-spectroscopic techniques for ultrasensitive and rapid detection of phosphate in food using Nile blue A as probe

Herein, a multi-spectroscopic assay based on a derivatization reaction was proposed for phosphate detection. In this assay, the phosphate with weak spectral signals was transformed to a large ion-association complex via a derivatization reaction. The operation procedure of the assay was easily performed by physically mixing sulfuric acid, derivatization reagent, phosphate (or sample solution), and dye probe (Nile blue A) for 10 min. Considerable changes in three types of spectral signals, i.e., resonance Rayleigh scattering (RRS), fluorescence, and ultraviolet-visible absorption, could be achieved. Under certain conditions, good linear relationship was obtained between each of the three signal variations and the phosphate concentration. The assay shows good selectivity and high sensitivity with limits of detection (LOD) of 4.8, 4.9 and 5.2 ng/mL for the RRS method, fluorophotometry and spectrophotometry, respectively. The multi-spectroscopic assay was applied to detect phosphate in real food samples, achieving recoveries of 93.3 %–109.6 % and relative standard divisions of 1.8 %–7.1 %. Owing to its speediness, easy operation, high sensitivity, good selectivity, self-comparison function, the multi-spectroscopic assay exhibits great potential for determination of phosphate in complex samples and provides an instructive strategy for detecting analytes with no or weak spectral signal.

Spectrophotometric Determination of Domperidone Maleate, Carvedilol, Dimetindene Maleate and Cinnarizine in Pharmaceuticals by Ion Association Complex Formation with Erythrosine B Dye

Spectrophotometric Determination of Domperidone Maleate, Carvedilol, Dimetindene Maleate and Cinnarizine in Pharmaceuticals by Ion Association Complex Formation with Erythrosine B Dye

Applying resonance Rayleigh scattering and spectrofluorimetric techniques for the selective determination of neomycin sulfate using Congo red as a probe: Applications for wastewater analysis.

Two simple, sensitive, and low-cost fluorescence spectroscopy methods for neomycin (NEO) detection were developed. Both methods were based on the interaction between NEO and Congo red (CR) in acidic buffer medium to form an ion-association complex. The quenching effect of the formed ion-association complex on the fluorescence of CR at 421 nm is a basic principle of fluorescence analysis, whilst the resonance Rayleigh scattering (RRS) method was used to enhance the resonance Rayleigh scattering spectrum at 384 nm by adding NEO. Experimental conditions such as pH, temperature, reaction time, CR concentration, and the ionic strength of the two methods were investigated and optimized. In addition, the effect of common coexisting substances on the method was tested and the results showed good selectivity. The composition of ion-association complexes, the reaction mechanism, and reasons for the enhanced intensity of RRS are discussed. Under optimum conditions, the responses of the fluorescence spectrophotometry and RRS methods showed good linearity with NEO concentrations in the range 0.2-3.0μg ml-1 and 0.1-3.0μg ml-1 , respectively. The detection limits of fluorescence spectrophotometry and RRS spectroscopy techniques were 0.02 μg ml-1 and 0.01 μg ml-1 , respectively. Finally, the two methods were applied to the analysis of wastewater and the results were satisfactory.

Development of Spectrophotometric Procedures for the Simultaneous Determination of Voxilaprevir, Sofosbuvir and Velpatasvir in Pure Form and in Tablets Ion-Association Complex Method

Two spectrophotometric procedures are developed for the estimation of three antihepatitic drugs namely Voxilaprevir (VOXL), Sofosbuvir (SOFOS) and Velpatasvir (VELP) in pure form and in different pharmaceutical formulations. The first method is based on the oxidation of velpatasvir and sofosbuvir with potassium iodate in an acidic medium followed by extracting the liberated iodine with cyclohexane and measurement at λ= 525 nm. Beer’s law is valid in the concentration ranges from 10–400 and 5–400 µg/ml for velpatasvir and sofosbuvir, respectively. The apparent molar absorptivity of the resulting-colored complex was found to be 1.34 × 10 for velpatasvir and sofosbuvir, respectively. The second method is based on the interaction of the antithepatatis drugs, Voxilaprevir, Velpatasvir and sofosbuvir in 1,2-dichloroethane with bromophenol blue (BPB), bromocresol green (BCG) and bromocresol purple (BCP) in the same solvent to produce stable colored ion pairs with maximum absorbance at 385–405 nm. Regression analysis of Beer’s plots showed good correlation in the concentration ranges 10–60, 10–60 and 5–40 µg/mL for voxilaprevir and 1.64 × 103 l.mol−1.cm−1 for velpatasvir, 10–150, 10–150 and 10–60 µg/mL−for sofosbuvir with BPB, BCG and BCP reagents, respectively. The limit of detection is 0.46–7.69 µgml11 for sofosbuvir and 10–250, 10–150 and 10–100 µgml−1 and limits of quantitation range between 1.52–8.53 µgml1. The optimum assay conditions were investigated and the recovery of the drugs from their dosage forms ranged from 99.33% to 100.5%. Intraday relative standard deviations (RSD) were 0.029–1.397% and the correlation coefficients ranged from 0.9992 to 1. The two methods can be applied successfully for the determination of these drugs in tablets. The results of analysis were validated statistically through recovery studies.

Simple Extractive Spectrophotometric Method for Determination of Favipiravir from Pharmaceutical Formulation

Simple sensitive and accurate extractive spectrophotometric methods have developed for the estimation of favipiravir in pharmaceutical dosage form. The methods are based on the formation of coloured complexes by the drug with reagents like bromophenol blue, solochrome dark blue and bromocresol green in acidic medium. The ion associated complexes were formed and quantitatively extracted under the experimental condition in chloroform. The absorbance values were measured at 420nm, 495nm and 430nm respectively. The proposed methods were validated statistically. Recoveries of methods were carried out by standard addition methods. The linearity was found to be 1.0-12.0μg/ml, 2-20μg/ml, 1-16μg/ml for methods 1, 2 and 3 respectively. The low values of standard deviation and percentage RSD indicate high precision of methods. Hence these methods are useful for routine estimation of favipiravir in tablets.

Ultrasensitive Chemically Modified Carbon Paste Sensor for Reliable and Selective Potentiometric Determination of Trace Amounts of Sitagliptin in Real Samples

AbstractA new chemically modified potentiometric carbon paste electrode was fabricated based on incorporation of the ion association complex of sitagliptin‐phosphotungstate to determine sitagliptin. The proposed sensor displayed a Nernstian slope of 59.4 mV/decade for sitagliptin over a concentration range of 1.7×10−8 to 2.2×10−5 M and a detection limit of 9.1×10−9 M. It represented the advantages of fast response, long lifetime and, most importantly, excellent selectivity for sitagliptin versus a wide variety of usual inorganic cations and also biological species such as amino acids and sugars. The temperature dependence of sensor potential was examined, and it was figured out that the sensor has a low thermal coefficient in the temperature range of 15–55 °C. The sensor was applied to determine sitagliptin in pharmaceutical tablets, milk and blood serum samples. The obtained suitable recoveries and relative standard deviations confirmed that the developed sensor could be precisely applied to determine sitagliptin in real samples.

Novel extractive visible spectrophotometric method for determination of antihypertensive drug irbesartan with sulfonephthalein acid dyes in tablets

Irbesartan (IRB) is one of the drugs used for the treatment of hypertension. The present work develops and validates two methods for the evaluation of irbesartan in bulk and tablets. Sulfonephthalein acid dyes, bromophenol blue (BPB), and bromocresol purple (BCP) were used to produce stable yellow ion-association complexes with the basic drug IRB in dry chloroform. The colored products are quantified spectrophotometrically at their corresponding λmax. The relation between the absorbed signal and the drug concentration was linear up to 45.0 μg mL-1 (n = 6, r ≥ 0.9998). LOD reaches 40 ng mL-1. The composition of the ion associates was found 1:1 by Job’s and mole ratio methods. Application of the suggested methods to dosage forms is presented with percentage recoveries ranging from 99.33% to 101.67%. The results of the analysis were validated statistically and compared with the official method. No interference was observed from common pharmaceutical adjuvants.

Absorption and Resonance Rayleigh Scattering Spectra of Ag(I) and Erythrosin System and Their Analytical Application in Food Safety.

In pH 4.4∼4.6 weakly acidic media, erythrosine (Ery) can react with Ag(I) to form hydrophobic ion-association complex, which can further aggregate to form nanoparticles with an average particle size of about 45 nm under the action of water phase extrusion and van der Waals force. As a result, it could lead to a decrease of absorbance, a significant enhancement of resonance Rayleigh scattering (RRS) and the appearance of a new emission spectrum. Based on these Phenomena, two new methods (spectrophotometry and RRS) were established for the determination of trace Ag(I). The detection limits for Ag(I) by spectrophotometry and RRS are 9.74 and 0.12 ng/ml, respectively. In this paper, we have investigated the formation of nanoparticles, the optimum reaction conditions, the influence factors, explored the reason for enhancement of the scattering intensity and the effect of coexisting substance. This research shows that RRS method not only has good selectivity and high sensitivity, but also is simple and rapid. Analyzing of actual samples and standard samples, the determination result of this method is consistent with that of standard methods (Flame atomic absorption spectroscopy). Thus the method had potential feasibility to analysis for Ag(I) in the environmental water samples, pharmaceutical, and food industries.

Qualitative and quantitative analysis of some co-existing colorants in some hard candies

Based on the results of qualitative analysis, a simple and accurate acidity-controlled absorption spectroscopy method for the determination of certain coexisting pigments in commercial candies is established. Using a Tris−HCl (pH 3.6) reaction medium, brilliant blue (BRI) and tartrazine (TAR) react with malachite green (MAG); tartrazine and sunset yellow (SUN) react with brilliant green (BRG); and curcumin (CUR) and sunset yellow react with crystal violet (CRY). They all form binary ion association complexes. Their linear range are 0.06–21.4 mg/L (BRI-MAG, 628 nm), 0.06–11.8 mg/L (TAR-MAG, 436 nm), 0.04–11.8 mg/L (TAR-BRG, 425 nm), 0.04–9.1 mg/L (SUN-BRG, 502 nm), 0.03–10.0 mg/L (SUN-CRY, 484 nm), and 0.03–11.1 mg /L (CUR-CRY, 390 nm), respectively. The detection limit and quantification limit of each system are 0.041 mg/L and 0.71 mg/kg (MAG system), 0.035 mg/L and 0.61 mg/kg (BRG system), and 0.030 mg/L and 0.52 mg/kg (CRY violet system), respectively. This method is simple, rapid, accurate, sensitive and selective. The coexisting pigments curcumin, tartrazine, sunset yellow, and brilliant blue can be determined without pigment separation and complex mathematical model. It has been used in the determination of actual candies with satisfactory results.

Green electrochemical and chromatographic quantifications of the extremolyte ectoine in halophilic bacterial cultures and related pharmaceutical preparations

The realistic implementation of electrochemistry into bacterial biosynthesis monitoring programs has always been a challenging task. In this study, two simple, rapid, selective, and sensitive potentiometric sensors were developed and optimized for quantitative analysis of the extremolyte / osmoprotector ectoine (ECT) in halophilic bacterial cultures and also in its related pharmaceutical products. The developed sensors were a Polyvinyl chloride membrane sensor (ECT-PVC) and a coated graphite sensor (ECT-CG). They were established based on the ion association complex of ectoine cation with phosphotungstic acid (ECT-PTA) counter anion as ion exchange site using dioctyl-phthalate (DOP) as a solvent mediator or plasticizer. The sensors exhibited fast, stable, selective, and linear Nernstian responses over a broad range of concentrations ranging from 1 × 10−5 to 1 × 10−2 M of the studied drug. The developed sensors were optimized and cross-validated with a proposed HPLC method according to ICH guidelines. The proposed methods were successfully employed to quantify the studied drug in three different types of halophilic bacterial cultures and in an ectoine nasal spray pharmaceutical product. The selected bacteria species were Chromohalobacter salexigens, Halobacillus halophilus, and Halomonas elongata. The proposed methods were statistically compared with the reported methods, demonstrating no significant difference with respect to accuracy and precision. Greenness and environmental impact were also evaluated for the proposed procedures, verifying that they were excellent green and eco-friendly analytical methods.

Spectrophotometric Determination of Molybdenum(VI) as a Ternary Complex with 4-Nitrocatechol and Benzalkonium Chloride.

A new liquid—liquid extraction system for molybdenum(VI) was studied. It contains 4-nitrocatechol (4NC) as a complexing chromogenic reagent and benzalkonium chloride (BZC) as a source of heavy cations (BZ+), which are prone to form chloroform-extractable ion-association complexes. The optimum conditions for the determination of trace molybdenum(VI) were found: concentrations of 4NC and BZC (7.5 × 10−4 mol dm−3 and 1.9 × 10−4 mol dm−3, respectively), acidity (3.75 × 10−2 mol dm−3 H2SO4), extraction time (3 min), and wavelength (439 nm). The molar absorptivity, limit of detection, and linear working range were 5.5 × 104 dm3 mol−1 cm−1, 5.6 ng cm−3, and 18.6–3100 μg cm−3, respectively. The effect of foreign ions was examined, and the developed procedure was applied to the analysis of synthetic mixtures and real samples (potable waters and steels). The composition of the extracted complex was 1:1:2 (Mo:4NC:BZ). Three possible structures of its anionic part [MoVI(4NC)O2(OH)2]2− were discussed based on optimizations at the B3LYP/3-21G level of theory, and simulated UV/Vis absorption spectra were obtained with the TD Hamiltonian.

Use of dye aggregation phenomenon for spectrophotometric and SIA-LAV determination of bismuth(III) as a specific ion association complex between tetraiodobismuthate and Astra Phloxine

A simple, rapid, highly sensitive and selective non-extraction spectrophotometric and sequential injection analysis with lab-at-valve (SIA-LAV) methods for the determination of bismuth(III) have been developed based on the formation of a specific ion association complex (IA) between tetraiodobismuthate(III) anion and the polymethine dye Astra Phloxine (AP). The changes in the absorption spectra resulting from the formation of the IA are explained in the framework of the exciton theory by the aggregation of dye ions. The analytical wavelength was chosen in the region of an intense narrow bathochromically shifted band with maximum at 600 nm related to the band of the aggregated dye in a specific IA. It was shown that any cationic dye, including representatives of triphenylmethane, rhodamine and polymethine dyes, is capable of forming specific IAs. One of the most important prerequisites for the formation of a specific IA is its relatively low solubility. The UV–visible spectrum of the AP cation was calculated using the time-dependent density functional theory (TD-DFT). Superiority of the TD-DFT with the Franck-Condon approximation, which takes into account vibronic effects, was shown over the traditional non-vibrationally resolved TD-DFT calculations. The PBE1PBE functional is the most suitable in comparison with the used M06, CAM-B3LYP, WB97XD and M11 functionals. Carrying out the chemical reaction and mixing in an external mixing chamber allowed the mixing conditions to be adapted to the requirements necessary for the complete formation of the specific IA. Thus, the maximum possible sensitivity was achieved, which was about an order of magnitude higher than when using the classical SIA approach. Calibration ranges and detection limits (indicated in parentheses) for the developed spectrophotometric and SIA-LAV procedures were 0.04–0.5 (0.01) and 0.1–1.7 (0.03) mg L−1, respectively. The molar absorptivity and Sandell's sensitivity were found to be 6.6 × 104 mol−1 L cm−1 and 3.16 × 10−3 μg cm−2, respectively. The proposed methods were successfully applied for the determination of bismuth content in pharmaceutical compositions and alloys.

Green and sensitive spectrofluorimetric method for the determination of two cephalosporins in dosage forms.

Using two green and sensitive spectrofluorimetric methods, we quantified two cephalosporins, cefepime (CFM) and cefazolin (CFZ), in raw and pharmaceutical formulations. The first method is based on the reaction between CFM and fluorescamine (borate buffer, pH 8), which yields a highly fluorescent product. After excitation at 384 nm, the fluorescent product emits light at 484 nm. At concentration ranges from 12.0 to 120.0 ng ml−1, the relative fluorescence intensity/concentration curve was linear with a limit of quantification (LOQ) of 2.46 ng ml−1. The second method relied on measuring the CFZ quenching action on acriflavine fluorescence through formation of an ion-associate complex using Britton–Robinson buffer at pH 8. We measured acriflavine fluorescence at 505 nm after excitation at 265 nm. The decrease in acriflavine fluorescence intensity was CFZ concentration-dependent. Using this method, we quantified CFZ in concentrations ranging from 1 to 10 µg ml−1 with a LOQ of 0.48 µg ml−1. We studied and optimized the factors influencing reaction product formation. Moreover, we adapted our methods to the investigation of the mentioned drugs in raw and pharmaceutical formulations with greatly satisfying results. We statistically validated our methods according to International Council on Harmonisation Guidelines. The obtained results were consistent with those obtained with the official high-performance liquid chromatography methods.

Paper-Based Potentiometric Sensors for Nicotine Determination in Smokers' Sweat.

Herein, we describe for the first time, the design and fabrication of a novel nicotine paper-based sensor, in which a miniaturized paper reference electrode is integrated for potentiometric measurements. The paper-based sensors were designed using printed wax barriers to define the electrochemical cell and the sample zones. The electrodes were based on the use of the ion association complexes of the nicotinium cation (Nic) with either tetraphenylborate (TPB) or 5-nitrobarbiturate (NB) counter anions as sensing materials for nicotine recognition. A poly (3,4 ethylenedioxythiophene)/poly-(styrene sulfonate) (PEDOT/PSS) conducting polymer was used as an ion-to-electron transducer. The performance characteristics of the proposed sensors were evaluated and it revealed a rapid and stable response with a Nernstian slope of 55.2 ± 0.3 and 51.2 ± 0.6 mV/decade over the linear range of 1.0 × 10–5 to 1.0 × 10–2 M and detection limits of 6.0 and 8.0 μM for [Nic/TPB] and [Nic/NB], respectively. The sensors revealed a constant response over the pH range 3.5–6.5. The designed sensors provided a portable, inexpensive, and disposable way of measuring trace levels of nicotine coming from different cigarettes and in the collected human sweat of heavy smokers. All results were compared favorably with those obtained by the standard gas chromatographic method.

Resonance Rayleigh scattering technique-using erythrosine B, as novel spectrofluorimetric method for determination of anticancer agent nilotinib: Application for capsules and human plasma

A exceedingly touchy resonance Rayleigh scattering (RRS) strategy for the assurance of nilotinib (NILO) was introduced. In the pH 3.4 acetate buffer solution, NILO reacted with erythrosine B to produce an ion-association complex, which increased the RRS intensity of the studied system. The enhanced RRS intensity (ΔI) was linearly proportional to the concentration of NILO, the linear range of the method was 0.1–1.0 µg/mL and the detection limit (DL) was 0.025 µg/mL. In like manner, this test was connected to distinguish the concentration of NILO in capsules and human plasma with palatable comes about.