scholarly journals A novel catalytic adsorptive stripping voltammetric method for the determination of germanium ultratraces in the presence of chloranilic acid and the V(IV)·HEDTA complex

2020 ◽  
Vol 24 (11-12) ◽  
pp. 2891-2899
Author(s):  
Jerzy Zarębski ◽  
Andrzej Bobrowski ◽  
Agnieszka Królicka ◽  
Julia Gonciarczyk ◽  
Vasiliki Manolopoulou ◽  
...  
Keyword(s):  
Limit Of Detection ◽  
Electrolyte Composition ◽  
Hanging Mercury Drop Electrode ◽  
Film Electrode ◽  
Optimal Conditions ◽  
Subsequent Reduction ◽  
Adsorbed State ◽  
Chloranilic Acid ◽  
Effects Of Ph

Abstract A novel, sensitive catalytic adsorptive stripping voltammetric procedure which can be used to determine trace amounts of germanium is described. The method is based on the interfacial accumulation of the complex formed by Ge(IV) and the product of the reduction of chloranilic acid on the hanging mercury drop electrode or the renewable silver amalgam film electrode, and its subsequent reduction from the adsorbed state followed by the catalytic action of the V(IV)·HEDTA complex. The presence of V(IV)·HEDTA greatly enhances the adsorptive stripping response of Ge. The reduction of the Ge(IV) in the presence of chloranilic acid and V(IV)·HEDTA was investigated in detail and the effects of pH, electrolyte composition, and instrumental parameters were studied. Under optimal conditions, the catalytic peak current of germanium exhibited good linearity for Ge(IV) concentrations in the range of 0.75–60 nM (for 60 s of accumulation at −0.1 V, r2 = 0.995) and a low limit of detection (LOD = 0.085 nM). The procedure was successfully applied to determine Ge in water samples.

Synthesis of CdTe/Fe3O4 for Quantitative Detection of BSA

2013 ◽  
Vol 446-447 ◽  
pp. 45-49
Author(s):  
Xiu Pei Yang ◽  
Xiao Cui Yang ◽  
Yu Li Fu ◽  
Xiu Mei Cheng ◽  
Zhi Jing Tan
Keyword(s):  
Ph Value ◽  
Limit Of Detection ◽  
Quantitative Detection ◽  
Relative Fluorescence Intensity ◽  
Optimal Conditions ◽  
Selective Determination ◽  
Straight Line ◽  
Line Equation ◽  
Effects Of Ph

A new kind of functionalized CdTe/Fe3O4was synthesized for the quantitative and selective determination of bovine serum albumin (BSA). The effects of pH value, reaction time, temperature and dosage of CdTe/ Fe3O4on the detection of BSA were investigated. Under optimal conditions, the straight line equation: F/F0=1.40412+0.07216 C (μmol/L) was found between the relative fluorescence intensity and the concentration of BSA in the range of 0.69-5.52 μmol/L, and the limit of detection was 0.18 μmol/L.

The polarographic and voltammetric determination of 2,6-dicyano-4-nitro-2'-acetylamino-4'-diethylaminoazobenzene

1990 ◽  
Vol 55 (6) ◽  
pp. 1508-1517 ◽  
Author(s):  
Jiří Barek ◽  
Dagmar Civišová ◽  
Ashutosh Ghosh ◽  
Jiří Zima
Keyword(s):  
Azo Dye ◽  
Differential Pulse ◽  
Differential Pulse Polarography ◽  
Determination Limit ◽  
Polarographic Reduction ◽  
Hanging Mercury Drop Electrode ◽  
Optimal Conditions ◽  
Pulse Polarography ◽  
Pulse Voltammetry

The polarographic reduction of the title azo dye was studied and optimal conditions were found for its analytical utilization in the concentration range 1 . 10-6 - 1 . 10-7 mol l-1 using differential pulse polarography and 1 . 10-6 - 1 . 10-8 mol l-1 using fast scan differential pulse voltammetry or linear scan voltammetry at a hanging mercury drop electrode. When the latter technique is combined with adsorptive accumulation of the studied substance on the surface of the hanging mercury drop, the determination limit can be further decreased to 3 . 10-9 mol l-1.

scholarly journals First Electrochemical Method of Nitrothal-Isopropyl Determination in Water Samples

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Dariusz Guziejewski ◽  
Agnieszka Nosal-Wiercińska ◽  
Sławomira Skrzypek ◽  
Witold Ciesielski ◽  
Sylwia Smarzewska
Keyword(s):  
Environmental Samples ◽  
Electrochemical Method ◽  
Concentration Level ◽  
Stripping Voltammetry ◽  
Adsorptive Stripping Voltammetry ◽  
Hanging Mercury Drop Electrode ◽  
Optimal Conditions ◽  
Step Potential ◽  
Accumulation Time

The aim of the research was the use of square wave adsorptive stripping voltammetry (SWAdSV) in conjunction with a hanging mercury drop electrode (HMDE) for the determination of nitrothal-isopropyl. It was found that optimal SW technique parameters were frequency, 200 Hz; amplitude, 50 mV; and step potential, 5 mV. Accumulation time and potential were studied to select the optimal conditions in adsorptive stripping voltammetry: 45 s at 0.0 V, respectively. The calibration curve (SWSV) was linear in the nitrothal-isopropyl concentration range from 2.0 × 10−7 to 2.0 × 10−6 mol L−1 with detection limit of 3.46 × 10−8 mol L−1. The repeatability of the method was determined at a nitrothal-isopropyl concentration level equal to 6.0 × 10−7 mol L−1 and expressed as RSD = 5.5% (n=6). The proposed method was successfully validated by studying the recovery of nitrothal-isopropyl in spiked environmental samples.

scholarly journals Fast and Sensitive Voltammetric Method for the Determination of Rifampicin on Renewable Amalgam Film Electrode

Sensors ◽  
2021 ◽  
Vol 21 (17) ◽  
pp. 5792
Author(s):  
Marek Szlósarczyk ◽  
Robert Piech ◽  
Anna Milc ◽  
Urszula Hubicka
Keyword(s):  
Supporting Electrolyte ◽  
Pulse Height ◽  
Pharmaceutical Formulations ◽  
Pharmaceutical Products ◽  
Film Electrode ◽  
Optimal Conditions ◽  
Step Potential ◽  
Voltammetric Method ◽  
Deposition Step

In this work, a new sensitive voltammetric method for the determination of rifampicin without time-consuming preconcentration is presented. The objective was to develop a simple, fast and sensitive voltammetric procedure for the analysis of rifampicin in pharmaceutical products. The cyclic renewable mercury film silver-based electrode (Hg(Ag)FE) was applied as a working electrode for this purpose. The optimal conditions for the determination of rifampicin were defined, in terms of the composition of supporting electrolyte (including pH) and instrumental parameters (potential and time of deposition, step potential, pulse height). The method was validated resulting in a satisfactory linearity range of 0.4–250.0 µgmL−1; the limits of detection and quantification are 0.12 µgmL−1 and 0.4 µgmL−1, respectively; and the repeatability of the method expressed as RSD is 4.1% (n = 6) with a surface area of 10.9 mm2. The proposed method was successfully applied in the analysis of rifampicin in simple and composed pharmaceutical formulations.

The polarographic and voltammetric determination of the 4'-haloderivatives of N,N-dimethyl-4-aminoazobenzene

1989 ◽  
Vol 54 (6) ◽  
pp. 1549-1563 ◽  
Author(s):  
Jiří Barek ◽  
Helena Haladová-Bláhová ◽  
Jiří Zima
Keyword(s):  
Differential Pulse ◽  
Voltammetric Determination ◽  
Differential Pulse Polarography ◽  
Determination Limit ◽  
Polarographic Reduction ◽  
Hanging Mercury Drop Electrode ◽  
Optimal Conditions ◽  
Pulse Polarography ◽  
Mixed Water

The polarographic reduction of 4-haloderivatives of N,N-dimethyl-4-aminoazobenzene has been studied in mixed water-methanol medium, a mechanism has been proposed and optimal conditions have been found for determination of these substances by TAST polarography with a determination limit of about 1.10-6 mol l-1, by differential pulse polarography with a determination limit of about 1.10-7 mol l-1 and linear scan voltammetry with a determination limit of about 5.10-8 mol l-1. In the latter technique, the determined substance was accumulated by adsorption on the surface of a hanging mercury drop electrode to decrease the determination limit below 1.10-8 mol l-1.

scholarly journals Development of Nanozyme-Labeled Biomimetic Immunoassay for Determination of Sulfadiazine Residue in Foods

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Jingbo He ◽  
Li Zhang ◽  
Longhua Xu ◽  
Feifan Kong ◽  
Zhixiang Xu
Keyword(s):  
High Performance ◽  
Detection Method ◽  
Limit Of Detection ◽  
Milk Powder ◽  
Template Molecule ◽  
Optimal Conditions ◽  
Maximum Residue Limit ◽  
Imprinted Polymer ◽  
Milk Samples

The excessive use and ingestion of residues of sulfonamides harm the human body and the environment. To meet the requirements of the maximum residue limit specified by the Ministry of Agriculture of China, a rapid detection method urgently needs to be developed. In the present study, a molecularly imprinted polymer (MIP) that could selectively recognize sulfadiazine (SDZ) was prepared using SDZ as the template molecule and methacrylic acid as the functional monomer. Using MIP as biomimetic antibody and Au@Pt@SiO2 nanozyme as a marker, a new biomimetic immunoassay was developed to detect sulfadiazine. Under the optimal conditions, the limit of detection (IC15) and sensitivity (IC50) of this method were 0.09 and 6.1 mg/L, respectively. To determine the accuracy of this method, honey and milk samples spiked with sulfadiazine were analyzed, with recoveries in the range of 70.8%-90.2%. The method was also used for the quantitative analysis of sulfadiazine residues in milk powder and milk samples, producing results which correlated well with those obtained by high-performance liquid chromatography.

scholarly journals Application of an Activated Carbon-Based Support for Magnetic Solid Phase Extraction Followed by Spectrophotometric Determination of Tartrazine in Commercial Beverages

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
José A. Rodríguez ◽  
Karen A. Escamilla-Lara ◽  
Alfredo Guevara-Lara ◽  
Jose M. Miranda ◽  
Ma. Elena Páez-Hernández
Keyword(s):  
Activated Carbon ◽  
Solid Phase Extraction ◽  
Limit Of Detection ◽  
Solid Phase ◽  
Magnetic Solid Phase Extraction ◽  
Phase Extraction ◽  
Optimal Conditions ◽  
Magnetic Solid ◽  
Nonalcoholic Beverages

A method is presented for magnetic solid phase extraction of tartrazine from nonalcoholic beverages. The method involves the extraction and clean-up by activated carbon covered with magnetite dispersed in the sample, followed by the magnetic isolation and desorption of the analyte by basified methanol. The tartrazine eluted from the magnetic support was determined by spectrophotometry. Under optimal conditions, the linear range of the calibration curve ranges from 3 to 30 mg L−1, with a limit of detection of 1 mg L−1. The method was validated by comparing the results with those obtained by HPLC. A precision of<5.0% was obtained in all cases and no significant differences were observed(P<0.05).

Determination of Se(iv) by adsorptive cathodic stripping voltammetry at a Bi/Hg film electrode

2015 ◽  
Vol 7 (5) ◽  
pp. 2121-2128 ◽  
Author(s):  
Parisa Sharifian ◽  
Alireza Aliakbar
Keyword(s):  
Water Samples ◽  
Limit Of Detection ◽  
Stripping Voltammetry ◽  
Open Circuit ◽  
Film Electrode ◽  
Limit Of Quantification ◽  
Cathodic Stripping Voltammetry ◽  
Analytical Range ◽  
Cathodic Stripping

Method and conditions: determination of trace amounts of Se(IV) by adsorptive cathodic stripping voltammetry at the Bi/Hg film electrode in an open circuit system; limit of detection: 0.07 ng mL−1; limit of quantification: 0.25 ng mL−1; RSD: 2.4% (for five replications of 5 ng mL−1 of Se(iv)); analytical range: 2–50 ng mL−1; interference: selective for Se(iv) – no interference; application: determination of Se(iv) in vegetable, fruits and water samples.

scholarly journals Optimization of Kieldahl digestion procedure for determination of mercury in lipstick by Box-Hunter design

2019 ◽  
Vol 16 (3) ◽  
pp. 41
Author(s):  
Nguyen Ngoc Hung ◽  
Huynh Thi Nhan ◽  
Bui Phuoc Hung ◽  
Nguyen Thi Tuyet Nhung ◽  
Phan Thi Hoang Yen
Keyword(s):  
Response Surface ◽  
Limit Of Detection ◽  
Mercury Content ◽  
Good Precision ◽  
Optimal Conditions ◽  
Good Recovery ◽  
Limit Of Quantification ◽  
Optimization Study ◽  
Cold Vapor Atomic Absorption

This article describes the application of response surface methodology to the development of a procedure for mercury determination by cold vapor atomic absorption spectroscopy (CV-AAS) in lipstick samples after digestion by Kieldahl method. A Box-Hunter matrix was used to find optimal conditions for the procedure through a response surface study. Three variables “time, temperature, volume of HNO3 acid” were regarded as factors in the optimization study. In optimized condition, the linearity range was 0.2 ÷ 15 µg/L while the limit of detection (LOD) and limit of quantification (LOQ) were 0.17 and 0.57 ppb, respectively. This method  presented good precision (RSD ≤ 8.2%) and good recovery (81%-109%). This method was applied to determine mercury in seven lipstick samples and the highest mercury content was 0.229 ± 0.016 mg/kg.

scholarly journals Spectrophotometric determination of neomycin sulphate in tablets form via reaction with ninhydrin reagent

2019 ◽  
Vol 10 (2) ◽  
pp. 1392-1396 ◽  
Author(s):  
Khalaf F Alsamarrai ◽  
Menaa Abdulsalam Al-Abbasi ◽  
Eman Thiab Alsamarrai
Keyword(s):  
Spectrophotometric Determination ◽  
Spectrophotometric Method ◽  
Calibration Curve ◽  
Limit Of Detection ◽  
Basic Medium ◽  
Optimal Conditions ◽  
Limit Of Quantification ◽  
Maximum Absorbance ◽  
Ninhydrin Reagent

A new, sensitive, simple and cheap spectrophotometric method for the determination of Neomycin Sulphate (NEO) in pharmaceutical forms has been developed. The method is based on the reaction between NEO and NIN in basic medium. The maximum absorbance was at 574 nm. The conditions affecting the reaction were optimized. Under the optimal conditions, the calibration curve was linear over the range of 0.0002-0.0011 mol/L. The limit of detection and limit of quantification were 5.423×10-6 mol/L, and 1.643×10-5 mol/L, RSD% of seven replicate was 0.8217- 0.8321% and Rec% was between 99.2168-100.8857%. The proposed method was successfully applied to the determination of NEO tablets form.

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