Analytical optimization of liquid-liquid extractive spectrophotometric assessment protocol for tetravalent platinum: Analysis of environmental samples and cisplatin.

An easy and reliable method is optimized for extractive spectrophotometric assessment of platinum(IV) with 4-(4'-nitrobenzylideneimino)-3-methyl-5-mercapto-1,2,4-triazole as an extractant. The basis of this method is the formation of red platinum(IV) complex with the above reagent in acetate buffer medium (pH 5.0) and extraction in chloroform. Good linearity with regression equation as y = 1.011 × 104 ×  + 0.002 having correlation coefficient (R2) of 0.998 over concentration up to 17.5 µg mL-1 of platinum(IV) was achieved with apparent molar absorptivity of 1.011 × 104 L mol-1 cm-1. The limit of detection (0.22 µg mL-1), limit of quantification (0.73 µg mL-1) and Sandell's sensitivity (0.0193 µg cm-2) were also estimated. The interference of various cations was removed by using proper masking agents and consequently by using EDTA and citrate to mask certain transition metals, the method becomes highly specific for platinum(IV), including the effects of platinum group metals. The method is effectively used for determination of platinum(IV) from environmental and real samples such as alloys, catalysts, thermocouple wire and pharmaceutical sample.

Preparation, Characterization and In Vitro Biological Activities of New Diphenylsulphone Derived Schiff Base Ligands and Their Co(II) Complexes.

The present work describes the chemical preparation of Schiff bases derived from 4,4'-diaminodiphenyl sulfone (L1-L5) and their Co(II) metal complexes. The evaluation of antimicrobial and anticancer activities against MCF-7 cell line and human lung cancer cell line A-549 was performed. The aforementioned synthesized compounds are characterized by spectroscopic techniques and elemental analysis confirms successful synthesis. The results from the above analytical techniques revealed that the complexes are in an octahedral geometry. The antimicrobial activity of the synthesized Schiff base ligands and their metal complexes under study was carried out by using the agar well diffusion method. The ligand and complex interactions for biological targets were predicted using molecular docking and high binding affinities. Further, the anticancer properties of the synthesized compounds are performed against the MCF-7 cell line and human lung cancer cell line A-549 using adriamycin as the standard drug.

In Vitro Anticancer Screening, Molecular Docking and Antimicrobial Studies of Triazole-Based Nickel(II) Metal Complexes.

Herein we describe the synthesis of a series of nickel(II) complexes (C1-C3) with Schiff bases (HL1-HL3) derived from 4-amino-5-mercapto-3-methyl-1,2,4-triazole and ortho/meta/para-nitrobenzaldehyde having composition [Ni(L)2(H2O)2]. The obtained ligands and their complexes were characterized using physico-chemical techniques viz., elemental analysis, magnetic moment study, spectral (electronic, FT-IR, 1H-NMR) and thermal analysis. The elemental analysis and spectral analysis revealed that Schiff bases behave as monoanionic bidentate ligands towards the Ni(II) ion. Whereas, the magnetic moment study suggested the octahedral geometry of all the Ni(II) complexes. The thermal behavior of the complexes has been studied by thermogravimetric analysis and agrees well with the composition of complexes. Further, the biological activities such as antimicrobial and antifungal studies of the Schiff bases and Ni(II) complexes have been screened against bacterial species (Staphylococcus aureus and Pseudomonas aeruginosa) and fungal species (Aspergillus niger and Candida albicans) activity by MIC method, the results of which revealed that metal complexes exhibited significant antimicrobial activities than their respective ligands against the tested microbial species. Furthermore, the molecular docking technique was employed to investigate the active sites of the selected protein, which indeed helped us to screen the potential anticancer agents among the synthesized ligand and complexes. Further, these compounds have been screened for their in vitro anticancer activity using OVCAR-3 cell line. The results revealed that the complexes are more active than the ligands.

Design and optimization of sensitive analytical spectrophotometric method for micro determination of copper(II) from e-waste by using of novel chromogenic extractant.

In this article, a novel spectrophotometric reagent 1-(pyrimidine)-4, 4, 6-trimethyl-1,4-dihydropyrimidine-2-thiol [PTPT] has been synthesized for liquid-liquid extraction and spectrophotometric determination of copper(II). The as-synthesized ligand has been selectively forms stable complex with copper(II) in basic medium (pH 9.0), in presence of mild pyridine the extraction and color stability has found to be synergistically enhanced. The equilibrium time is 10 min for effective extraction of copper(II) from organic phase and absorbance of colored organic complex in carbon tetrachloride is measured spectrophotometrically at λmax 615 nm against reagent blank. The ternary complex of Cu(II)-PTPT-Py having molar ratio 1:2:2 (M:L:Py) showed green colored complex. The main factors influencing the achievement of synergistic extraction; i.e. pH, ligand concentration, type and volume of the dispersive organic solvents, equilibrium time, synergent concentration and foreign ions were investigated. The Beer's law was obeyed in the concentration range 1-20 µg mL-1 of copper(II) and optimum concentration range is evaluated by Ringbom's plot and it is found that 2.5-25 µg mL-1. In presence of pyridine, molar absorptivity and Sandell's sensitivity of copper(II)-PTPT complex is 2.80 × 103 L mol-1 cm-1 and 0.226 µg cm-2, respectively and in absence of pyridine, molar absorptivity and Sandell's sensitivity of copper(II)-PTPT complex is 1.35 × 103 L mol-1 cm-1 and 0.469 µg cm-2, respectively. The stoichiometry of the copper(II)-PTPT-pyridine complex was calculated by slope ratio method, mole ratio method and Job's method of continuous variation and it has been found as 1:2:2. No significant effects of potentially interfering species i.e. cations and anions were observed. The optimized method was applied for the determination of copper(II) in binary, synthetic mixtures and successfully applied for determination of copper(II) from e-waste samples. The standard deviation (R.S.D.) is 0.11% for n = 5 repetition. The reliability of the developed method is confirmed by comparison of experimental results with atomic absorption spectrophotometer.

Highly reproducible, simple and selective analytical method for extractive UV-visible spectrophotometric determination of ruthenium(III): Analysis of catalyst, fissium alloy and sequential separation.

An easy and selective method has been developed for the extractive spectrophotometric determination of ruthenium(III) with 4-(4'-flurobenzylideneimino)-3-methyl-5-mercapto-1,2,4-triazole (FBIMMT) as a chelating reagent. The basis of the method is the formation of stable complex of 'soft base' FBIMMT with 'soft acid' ruthenium(III). The reagent FBIMMT in n-butanol easily forms extractable yellow coloured complex with ruthenium(III) in acetate buffer of pH 4.8. The absorbance of [Ru(III)-FBIMMT] complex is measured at 394 nm against the reagent blank. Good linearity range of concentration up to 27.0 µg mL-1 of ruthenium(III) is attained with correlation coefficient R2 = 0.998. The optimum concentration range is 6 to 27.0 µg mL-1 which is deduced by Ringbom's plot. The apparent molar absorptivity found to be 2.75 × 103 L mol-1 cm-1. Some additional characteristics such as limit of detection (LOD = 0.48 µg mL-1), limit of quantification (LOQ = 1.19 µg mL-1), and Sandell's sensitivity (SS = of 0.0367 µg cm-2) are also estimated. The composition of [Ru(III)-FBIMMT] complex has been established from Job's continuous variation method, mole ratio method, and log-log plot method. The specificity towards ruthenium(III) is well studied and appropriate masking agents are applied wherever required to boost it. The intra-day and inter-day precision values are found to be brilliant with % relative standard deviation of 0.52 and 0.68 respectively with % accuracy within the range of 99.00-100. The method is effectively used for determination of ruthenium(III) from water samples, binary and ternary synthetic mixtures, fissium alloy samples and catalyst materials. A scheme for sequential group separation of ruthenium(III), palladium(II) and osmium(VIII) has also been developed. The reproducible results of the present method confirm that the method has a good potential for quantitative determination of ruthenium(III) from various matrices.

An efficient, cost effective, sensing behaviour liquid-liquid extraction and spectrophotometric determination of copper(II) incorporated with 4-(4'-chlorobenzylideneimino)-3-methyl-5-mercapto-1, 2, 4-triazole: Analysis of food samples, leafy vegetables, fertilizers and environmental samples.

The aim of the present work is to develop an efficient, simple and selective moreover cost-effective method for the extractive spectrophotometric determination of copper(II) by using the Schiff base 4-(4'-chlorobenzylideneimino)-3-methyl-5-mercapto-1, 2, 4-triazole [CBIMMT]. This chromogenic reagent forms a yellow coloured complex with copper(II) in acetate buffer at pH4.2. The copper(II) complex with ligand is instantly extracted into chloroform and shows a maximum absorbance at 414nm which remains stable for >48h. The composition of extracted complex is found to be 1:2 [copper(II): reagent] which was ascertained using Job's method of continuous variation, mole ratio method and slope ratio method. Under optimal conditions, the copper(II) complex in chloroform adheres to Beer's law up to 17.5µgmL-1 of copper(II). The optimum concentration range obtained from Ringbom's plot is from 5µgmL-1 to 17.5µgmL-1. The molar absorptivity, Sandell's sensitivity and enrichment factor of the extracted copper(II) chelate are 0.33813×104Lmol-1cm-1, 0.01996µgcm-2 and 2.49 respectively. In the extraction of copper(II), several affecting factors including the solution pH, ligand concentration, equilibrium time, effect of foreign ions are optimized. The interfering effects of various cations and anions were also studied and use of masking agents enhances the selectivity of the method. The chromogenic sulphur containing reagent, 4-(4'-chlorobenzylideneimino)-3-methyl-5-mercapto-1, 2, 4-triazole has been synthesized in a single step with high purity and yield. The synthesized reagent has been successfully applied first time for determination of copper(II). The reagent forms stable chelate with copper(II) in buffer medium instantly and quantitatively extracted in chloroform within a minute. The method is successfully applied for the determination of copper(II) in various synthetic mixtures, complexes, fertilizers, environmental samples such as food samples, leafy vegetables, and water samples. The results are compared with those obtained with a reference procedure. Good agreement was attained. All the obtained results are indicative of a convenient, fast method for the extraction and quantification of micro levels of copper(II) from various environmental matrices without use of sophisticated instrumentation and procedure. The method showed a relative standard deviation of 0.42%.

Liquid anion exchanger study of gold (III) from aqueous halide media with N-n-octylaniline.

N-n-octylaniline in xylene is used for the extractive separation of gold(III) from halide media. Gold(III) was extracted quantitatively with 10 ml of 2% reagent in xylene from 0.5-10 M and 0.5-8 M hydrochloric acid and hydrobromic acid, respectively. It was stripped from the organic phase with ammonia buffer solution (pH 10.1) and estimated spectrophotometrically with stannous chloride. The effect of metal ion, acids, reagent concentration and of various foreign ions has been investigated. Method is applicable to the analysis of synthetic mixtures containing platinum metals and alloy samples. The method is fast, accurate and precise.