Determination Of Micro Amounts Research Articles

Determination of Micro Amounts of Promethazine Hydrochloride in Pure and Pharmaceutical Samples Using UV- Visible Spectrophotometry

This study presents the development of a novel, facile, and overly sensitive spectrophotometric approach for quantifying promethazine hydrochloride (PRO) within its pharmaceutical formulations. The method capitalizes on an oxidative coupling reaction, achieved through the oxidation of the compound in an acidic milieu utilizing ammonium cerium (IV) sulfate dehydrate (Ce+4) solution. This process leads to the creation of a green-colored solution, which, upon conjugation with 5-aminosalicylic acid, exhibits maximum absorption at a wavelength of 598 nm. The methodology investigated several parameters, encompassing oxidation duration, temperature, quantities of oxidizing agent and coupling reagent, and determining the stoichiometric ratio between promethazine hydrochloride and 5-aminosalicylic acid. The established ratio was confirmed to be 1:1. Numerous organic solvents were evaluated, with water emerging as the optimal choice due to its pronounced absorption characteristics at the 598 nm wavelength. The applicability of Beer's law was verified over a concentration range of 2 - 28 μg/mL of promethazine hydrochloride, with a calculated molar absorption coefficient of 1.9606 x 104 L/mol∙cm. The Sandell sensitivity index was determined as 0.0164 μg/cm2, while the relative standard deviation (RSD) ranged from 0.8553- 1.2671%. Notably, recovery percentages were also within the 99.88 – 100.34% range. The efficacy of this technique was effectively demonstrated through its successful application in the analysis of pharmaceutical formulations containing promethazine hydrochloride, employing the standard method as a benchmark.

Photometric Determination of Cobalt (Ii) With 4-Sulfo β-Nitroso α-Naphthol

At the moment development of science and technology sets important tasks for the science of analytical chemistry. Toxic compounds from various biological and industrial facilities and the development of methods for the separation and detection of their decomposition products one of the main tasks of analytical chemistry.
 Photometric detection, one of the most modern physical and chemical methods for the detection of heavy metals, is widely used today and the new organic reagents are being used to address these issues.
 Photometric determination of micro quantities of elements using organic reagents is one of the new developing methods. Photometric method is fast in nature and does not require expensive equipment with fast and cheap selective action.

SORPTION AND X-RAY FLUORESCENCE DETERMINATION OF MICRO QUANTITIES OF SOME TOXIC METALS IN NATURAL OBJECTS AFTER THEIR PRECONCENTRATION ON MODIFIED SILICA GEL

A method for X-ray fluorescence determination of trace amounts of Pb(II), Cd(II) and Hg(II) ions (up to 250 μg/ml) directly in the sorbent phase after their extraction from solutions in a dynamic sorption mode has been developed. Merck silica gel (particle d 0.1-0.2 mm, specific surface 428.61 m2/g), chemically modified with 4-(2-pyridylazo)-resorcinol functional groups in one step, was used as a sorbent. An energy dispersive X-ray fluorescence analyzer with a semiconductor detector "ElvaX" ("Elvatex", Kyiv) was used in the study.
 It was found that the combined analysis of micro quantities of Pb, Cd and Hg by sorption-x-ray fluorescence method after their preconcentration on silica gel with chemically fixed surfactant requires the use of calibration curves for each metal, taking into account the presence of other ions in solutions.
 The developed by us method of sorption-x-ray fluorescence determination of micro quantities of Pb(II), Cd(II) and Hg(II) after their extraction and preconcentration on silica gel with chemically fixed 4-(2-pyridylazo)-resorcinol can be effectively used for the analysis of natural and man-made objects of complex chemical composition.

Spectrophotometric Determination of Micro Amount of Chromium (III) Using Sodium 4-((4,5-diphenyl-imidazol-2-yl)diazenyl)-3-hydroxynaphthalene-1-sulfonate in the Presence of Surfactant, Study of Thermodynamic Functions and Their Analytical Applications

Using sodium4-((4,5-diphenyl-imidazol-2-yl)diazenyl)-3-hydroxynaphthalene-1-sulfonate (SDPIHN) as a chromogenic reagent in presence of non-ionic surfactant (Triton x-100) to estimate the chromium(III) ion if the wavelength of this reagent 463 nm to form a dark greenish-brown complex in wavelength 586 nm at pH=10,the complex was stable for longer than 24 hours. Beer's low, molar absorptivity 0.244×104L.mol-1.cm-1, and Sandal's sensitivity 0.021 µg/cm2 are all observed in the concentration range 1-11 µg/mL. The limits of detection (LOD) and limit of quantification (LOQ), respectively, were 0.117 µg/mL and 0.385µg/mL. (mole ratio technique, job's method) were employed to investigate the stoichiometry of complexes, and both methods revealed that the metal to reagent ratio is equal 1:3.The absorption impact value of the reagent concentration, surfactant concentration, pH, reaction duration, temperature, addition sequences, ionic strength, masking agent, and the influence of many parameters such as affect cations and anions, among others. The influence of temperature on the reaction, which was referred to as an exothermic reaction, was also taken into account while calculating thermodynamic functions. Researchers investigated some of the complex solid's physical properties, such as solubility, molar conductivity, and melting point, as part of its development. UV-visible rays were used to investigate the chromium complex, while Relative Standard Deviation (RSD%) and Relative Error (E %) were used to assess the precision and accuracy of the novel method.

Extraction for Mo(VI), W(VI) and Mn(VII) as Oxyanions by Incorporation Cloud Point with Liquid Ion Exchange Methods

Highly sensitive method for separation and determination of micro amount of oxyanion for Mo(VI), W(VI), and Mn(VII) was performed. It has been done after formation of ion pair association complexes with Safranin as complexing agent including joint cloud point extraction with liquid ion exchange methods in the presence of non-ionic surfactant Triton X–100. The study is based on the values of wavelength of maximum absorbance, λmax= 536, 533, and 534nm respectively. Optimal conditions have been pinpointed high extraction efficiency needed for HCl concentration (1.0, 1.0 and 0.6) M respectively in the presence of 50µg metal ions in 10mL aqueous solutions. Besides, the stoichiometry of probable extracted structure of ion pair complexes was1:1:1 for all extracted complex, in addition to other effective parameters on extraction efficiency in this study.

Spectrophotometric determination of micro amount of mercury (II) using an (Azo) derivative in the presence of surfactant

Imidazole azo ligand (DPIDA), one of the azo compounds, was prepared and tested in the sample. In addition to the regular azoth protocol. Because of their ability to form stable complexes with metal ions in some oxidation states, imidazole azo ligands are important heterocyclic azo ligands in coordination chemistry. The complexation of the imidazole azo ligand (DPIDA) was accomplished by adding 4,5-diphenyl imidazole and N1, N1-dimethylbenzene1,4-diamine dihydrochloride. Measurements of 1HNMR, IR, UV-Vis, and molarity Their conductivity demonstrates their octahedral geometry with a bidentate ligand coordinated from an (N3) atom of the imidazole ring and one nitrogen atom of the azo group. The thesis also looked at using this reagent was used to do spectroscopy with the mercury (II) ion in binary water solution, and it was revealed that the reagent is difficult with the ion and has the highest sensitivity. The exact wavelength of absorption is (554) nm (pH = 6). Even though the pH was higher in the concentration range of (0.1 – 6.0 g /mL) with adherence to Beer's law, it was revealed to be a dynamic mercury pair reagent with the stability of more than (24 hours).

REMOVAL OF LEAD (II) WITH POLY 3-(AZA-18-CROWN-6) SILICA BONDED PHASE FROM SUCCINATE MEDIUM AND SAMPLES ANALYSIS

A method was described for the determination of micro amount of lead (II) with Poly 3-(Aza-18-crown-6) Silica bonded phase employed as an ion-pair forming a neutral complex from Sodium succinate medium (0.01 to 3.0 M). The adsorbed ion-pair complex was back eluted with 0.5 M hydrochloric acid and determined spectrophotometrically with PAR. The various parameters like concentration of acid, equilibrium time, back eluting agents, loading capacity were optimized for quantitative adsorption of lead (II). The applicability of the proposed method was successfully applied to the analysis of diverse ions, binary mixture of associated metal ions, ternary mixtures, alloys, ayurvedic samples and water samples and lead (II) was determined with the PAR and results of analysis were confirmed by AAS.

Regularities of transformation of dimethoate in apple agrocenoses

The aim of the research was to identify the regularities of dimethoate transformation in apple agrocenoses under the influence of protection technologies.Methods. The work was done in Toxicological laboratory of the North Caucasus Federal scientific center of horticulture, viticulture, winemaking. The research was conducted in field and laboratory conditions with using of methodological approaches based on modern methods and techniques. The pilot territory was laid in close corporation PPF Central. The extraction of analyzed compounds by plant and soil material is carried out according to the "Guidelines for the determination of micro-quantities of pesticides in plants, processed products, soil and water".Results. The background determination of organophosphate pesticides in soil before the planned treatments during this year revealed: the substance of dimethoate is higher the hygienic regulations in 1.3-1.4 times in 53% of the examined samples. During the harvest period, the content of dimethoate in all soil samples exceeded the permissible concentration, in the control version includes 0.3-0.5 PC of dimethoate. The accumulation of dimethoate is associated with its ability to react with complexing metal ions, which count in our soils is sufficient.Conclusion. Compiling the apple protection system is recommended to take into account that the annual using of dimethoates implying a violation of hygienic standards in soil and apple fruits. If there is a single application, residual amounts of dimethoate are in apple fruits, and their concentrations are exceeding or staying in the maximum permissible level. The samples were taken after 40 days of treatment. We recommend to exclude these insecticides (including D. V. dimetoate) from the apple tree protection system or use single application every 2 years in the first half of growing season.

Trace Determination of Thorium with 6-Chloro-3-hydroxy-2- (2′-furyl)-4H-chromen-4-one as an Analytical Reagent

A simple, rapid, highly sensitive and selective method for the spectrophotometric determination of micro amounts of thorium(IV) has been worked out using 6-chloro-3-hydroxy-2-(2′-furyl)-4H-chromen-4-one (CHFC) as a complexing agents in a acidified (CH3COOH, pH 3.5) medium. The yellow complex shows a maximum absorbance at 425-435 nm. The method obeys Beer′s law upto 3.5 μg Th cm-2. As many as 31 cations and 11 anions and/or complexing agents do not interfere. The method has good reproducibility and can be satis-factorily applied to the determination of thorium in samples corresponding to Australian monazite in composition.

Fluorometric Flow Injection Method for the Determination of Ammonia based on Hantzsch Reaction and Its Application to Ammonia Determination in the Atmosphere Original Paper

A Hantzsch reaction was, for the first time, applied to the determination of ammonia, and a novel, simple and highly sensitive method based on the reaction among ammonia, acetylacetone and formaldehyde was developed. The yellow color product, 3,5-diacetyl-1,4-dihydrolutidine, was detected fluorometrically at an excitation wavelength (λex) of 420 nm and an emission wavelength (λem) of 505 nm. The reaction conditions were optimized, and then the method was successfully applied to ammonia determination in the atmosphere. The optimal conditions were examined with respect of improving the sensitivity of ammonia determination under the moderate conditions. Under the optimized conditions, the proposed method was characterized by a linear calibration with a correlation coefficient of 0.9995 in the range of 1x10 M to 5x10 M. Sample throughput of 21 h, the standard deviation (RSD) of 0.56% (n=8) for 1x10 M ammonia standard solution, and the detection limit of 10 M (S/N=3) were achieved. The interference from cations and anions was also investigated. The proposed method was applied to the determination of micro amounts of ammonia in indoor and outdoor air by coupling with a batchwise collection/concentration method.

Inversion-chronopotentiometric determination of microquantities of nickel and cobalt in waters

The technique has been developed for measuring microconcentrations of nickel and cobalt in aqueous solutions and natural water by means of pulse inversion chronopotentiometry having sufficient reproducibility and accuracy by criteria of metrological certification.

Kinetic-spectrophotometric determination of neomycin

A new kinetically-based spectrophotometric method for the determination of micro quantities of neomycin is described in this paper. It is an adaptation of the modified Berthelot method which is a widely used colorimetric procedure for urea determination. The method was developed due to neomycin effect on 2,2′-dicarboxyindophenol formation. The experimental conditions for successful determination of neomycin were optimized. The relative standard deviation (RSD) for the neomycin concentration interval of 77–154 μg/mL, ranges from 0.7 to 1%. The method was directly applied to determining neomycin in ophthalmic drops. The obtained results in analyzed pharmaceutical samples were in accordance with disc-diffusion microbiological method results.

Spectroscopic, analytical and DFT calculation studies of two novel Al3+ complexes derived from 2,4,6-tri-(2-pyridyl)-1,3,5-triazine (TPTZ)

In this study TPTZ is used exclusively as an analytical reagent for the determination of micro amounts of Al3+ ions with high accuracy and lower detection limit, which reach 2.7ppm. The developed blue color of Al3+-TPTZ complex was used selectivity to determine the concentration and the geometry of the Al3+ complex using continuous variation and molar ratio methods. Also, the novel Al3+ complexes derived from the reaction of TPTZ were synthesized. The solid complexes were characterized by elemental analyses, spectral (IR, UV–vis., 1H NMR, mass) and magnetic measurements. The isolated complexes have the general formulae, [Al(TPTZ)Cl3]·H2O·1½EtOH (1:1; M:L) and [Al2(TPTZ)Cl6(EtOH)2] (2:1; M:L). IR spectra indicate that TPTZ behaves in a bidentate manner in case of 1:1 and 2:1 (M:L). Elemental analyses and mass spectra of the complexes suggest the existence of an octahedral structure around the Al3+ ions. DFT calculations were used to determine the geometry of complexes.

Determination of Micro Amount of Hydrogen Peroxide by a Zero-emission FIA System with Immobilized Peroxidase Enzyme Reactor Column

Determination of Micro Amount of Hydrogen Peroxide by a Zero-emission FIA System with Immobilized Peroxidase Enzyme Reactor Column

Abstracts of the 17th International Symposium on Bioluminescence and Chemiluminescence ‐ (ISBC 2012)

WARNING : The light-emitting molecular structures responsible for the chemiluminescence and fluorescence phenomena are not necessarily the same!

Colorimetric Determination of micro amounts of Sulfate in Rainwater by Reagents of 2-Aminoperimedine coupled to Dinitrosulfonazo III

Colorimetric Determination of micro amounts of Sulfate in Rainwater by Reagents of 2-Aminoperimedine coupled to Dinitrosulfonazo III

Validated Spectrophotometric Assay of Cefepime Hydrochloride and Cefuroxime Sodium Using a Tetrazolium Salt

A simple, rapid and sensitive spectrophotometric method for the determination of micro amounts of cefepime hydrochloride and cefuroxime sodium is described. The method is based on reduction of 2,3,5‐triphenyltetrazolium chloride (TTC) by the cited drugs in slightly alkaline medium leading to formation of a highly colored formazan derivative. Different variables affecting the color development were investigated and optimized. Absorbance measurements were made at 483 nm. Under the proposed conditions, this method is applicable over concentration range of 4–50 µg ml-1 with molar absorpitivities ranging from 5.208 x 103–1.217 x 104 L.mol-1.cm-1 and Sandell′s sensitivities ranging from 1.007 x 10-3–2.727 x10-3 µg cm-2. The proposed method was successfully applied for analysis of the cited drugs in formulations and the recovery percentages ranged from 99.47 to 99.8%. The results obtained demonstrated that the proposed method is equally accurate, precise and reproducible as the reported methods thus it is recommended for quality control and routine analysis where time, cost effectiveness and high specificity of analytical techniques are of great importance.

Determination of micro amounts of 3-(dithien-2-ylmethylene)-1-methylpiperidine, a non-narcotic antitussive.

Abstract A specific colorimetric method for the determination of micro amounts of 3-(dithien-2-ylmethylene)-1-methylpiperidine, a new antitussive and expectorant, is described. Depending on amount, a characteristic colour varying from rose pink to deep bluish purple appears when 2 volumes of a 0·01% solution of ninhydrin in concentrated sulphuric acid are added to 1 volume of an aqueous solution of the drug. After 24 hr at room temperature the colour produced has an absorption maximum at 590 mμ and follows Beer's Law over the range 1–25 μg/ml. The colour is specific for the drug and is sensitive at the μg/ml level. Recoveries from aqueous solution and human urine were 97·4 ± 2·1 and 97·4 ± 1·7% respectively.

Triphenyltetrazolium chloride as a new analytical reagent for molybdenum(VI): Application to plant analysis

Solvent extraction of molybdenum(VI) ion associate with triphenyltetrazolium chloride (TTC) has been studied. TTC was proposed as reagent for the spectrophotometric determination of micro amounts of molybdenum(VI) at λmax 250 nm. The optimum conditions for extraction of molybdenum(VI) as an ionassociation complex with TTC has been determined. Beer’s law is obeyed in the range of 0.5–10 μg/mL molybdenum(VI). The molar absorptivity of the ion-pair is 1 × 106 L/mol cm. The sensitivity of the method is 9.6 × 10−5 μg/cm2. The characteristic values for the extraction equilibrium and the equilibrium in the aqueous phase are: distribution constant KD = 32.64, extraction constant Kex = 2.19 × 1010 association constant β = 6.71 × 108. The interferences of different cations, anions on molybdenum(VI) determination were also investigated. A sensitive and selective method for the determination of microquantities of molybdenum(VI) has been developed. The determination was carried out without preliminary separation of molybdenum. A novel procedure of molybdenum(VI) extraction and spectrophotometric determination in different plant samples was examined.

An improved colorimetric determination of micro amounts of chromium(VI) and chromium(III) using p-aminoacetophenone and phloroglucinol in different samples

The reaction of Cr(VI) with hydroxylamine resulting in its oxidation to nitrite has been utilized for the determination of chromium. The nitrite thus liberated diazotizes p-aminoacetophenone to form diazonium salt which is further coupled with phloroglucinol in an alkaline medium, to form an azo dye. The dye gave maximum absorbance at 420 nm and when extracted in an amino cartridge obeyed Beer’s law in the range from 0.04 to 0.36 μg/mL of Cr(VI) and has a molar absorptivity of 1.04 × 105 L/mol cm. Optimum reaction conditions for diazotization, full colour development and the effect of variables such as temperature, time, and pH have been studied. The proposed method was applied to the determination of chromium in certified samples, air particulates, industrial effluents, and pharmaceutical preparations. The results are in agreement with those obtained by atomic absorption spectrometry.