RETRACTED: Preconcentration and solid-phase extraction of beryllium, lead, nickel, and bismuth from various water samples using 2-propylpiperidine-1-carbodithioate with flame atomic absorption spectrometry (FAAS).

This article has been retracted at the request of the Editors-in-Chief. Please see Elsevier Policy on Article Withdrawal (http://www.elsevier.

RETRACTED: Simultaneous flow-through determination of nitrites, nitrates and their mixtures in environmental and biological samples using spectrophotometry.

This article has been retracted at the request of the Editors-in-Chief. Please see Elsevier Policy on Article Withdrawal (http://www.elsevier.

Facile and sensitive determination of selenium (IV) in pharmaceutical formulations by flow injection spectrophotometry.

An automated flow injection spectrophotometric method has been developed for the rapid, simple, selective, and sensitive determination of selenium (IV) from various pharmaceutical multivitamin and mineral formulations. The method was based on the oxidation of 4-aminoantipyrine (4-amino-l,2-dihydro-1,5-dimethyl-2-phenyl-3H-pyrazole-3-one; 4-AAP) by selenium in presence of acidic medium and the coupling with N-(naphthalen-l-yl)ethane-1,2-diamine dihydrochloride (NEDA) to give a violet color derivative. Gilson P2 mini pulse peristaltic pump has been used for introducing the selenium (IV), dilute HCl, 4-AAP and NEDA solutions into reaction coil by an automatic system.

Facile and sensitive spectrophotometric determination of vanadium in various samples.

Novel reactions were developed for facile, sensitive and selective rapid spectrophotometric determination of trace amounts of vanadium(V) in various samples. The methods were based on the interactions of 3-methyl-2-benzothiazolinone hydrazone hydrochloride (MBTH) with N-(1-naphthyl)ethylenediamine dihydrochloride (NEDA) in the presence of vanadium to give blue colored derivative or on oxidation of dopamine hydrochloride (DPH) by vanadium in acidic medium and coupling with MBTH to yield pink color derivative. The blue color derivative having an absorbance maximum at 595nm was stable for 9 days and the pink color derivative with λ(max) 526nm for 5 days.

Speciation determination of chromium(III) and (VI) using preconcentration cloud point extraction with flame atomic absorption spectrometry (FAAS).

bis-[2-Hydroxy-1-naphthaldehyde] thiourea was synthesized and preconcentration cloud point extraction (CPE) for speciation determination of chromium(III) and (VI) in various environmental samples with flame atomic absorption spectrometry (FAAS) has been developed. Chromium(III) complexes with bis-[2-hydroxynaphthaldehyde] thiourea is subsequently entrapped in the surfactant micelles. After complexation of chromium(III) with reagent, the analyte was quantitatively extracted to the surfactant-rich phase in the non-ionic surfactant Triton X-100 after centrifugation.

WITHDRAWN: Copper(II) preconcentration on Amberlite XAD-2010 loaded microorganisms prior to its spectrophotometric determination.

This article has been withdrawn consistent with Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy).

Preconcentration and solid phase extraction method for the determination of Co, Cu, Ni, Zn and Cd in environmental and biological samples using activated carbon by FAAS.

2-{[1-(2-Hydroxynaphthyl) methylidene] amino} benzoic acid (HNMABA) was synthesized for solid phase extraction (SPE) to the determination of Co, Cu, Ni, Zn and Cd in environmental and biological samples by flame atomic absorption spectrophotometry (FAAS). These metals were sorbed as HNMABA complexes on activated carbon (AC) at the pH range of 5.0+/-0.

RETRACTED: Development of novel reactions for the simple and sensitive spectrophotometric determination of vanadium in various samples.

This article has been retracted at the request of the Editors-in-Chief. Please see Elsevier Policy on Article Withdrawal (http://www.elsevier.

Solid phase extraction method for the determination of lead, nickel, copper and manganese by flame atomic absorption spectrometry using sodium bispiperdine-1,1'-carbotetrathioate (Na-BPCTT) in water samples.

A novel column solid phase extraction procedure was developed for the determination of lead, nickel, copper and manganese in various water samples by flame atomic absorption spectrometry (FAAS) after preconcentration on sodium bispiperdine-1,1'-carbotetrathioate (Na-BPCTT) supported by Amberlite XAD-7. The sorbed element was subsequently eluted with 1M nitric acid and the acid eluates are analysed by Flame atomic absorption spectrometry (FAAS). Various parameters such as pH, amount of adsorbent, eluent type and volume, flow-rate of the sample solution, volume of the sample solution and matrix interference effect on the retention of the metal ions have been studied.

Inductively coupled plasma-optical emission spectrometry for on-line determination of multi trace elements in environmental samples after preconcentration by using Borassus flabellifer inflorescence loaded with 2-propylpiperidine-1-carbodithioate.

A procedure was developed for the determination of Cu, Mn, Pb, Cd, Co, Cr, and Zn in water samples by Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES) after preconcentration on synthesized 2-propylpiperidine-1-carbodithioate supported by Borassus flabellifer Inflorescence (BFI). The sorbed element was subsequently eluted with 0.4 M HNO3, and the acid eluates were analyzed by ICP-OES.

Spectrophotometric determination with a chromogenic reagent of lead in vegetables.

A method was developed for the simple, selective, and sensitive spectrophotometric determination of lead in vegetables with synthesized chromogenic reagent 3-[(2,6-dibromo-4-methylphenyl)diazenyl]-4,5-dihydroxy-6-[(2,4,6-tribromophenyl)diazenyl]naphthalene-2,7-disulfonic acid (DBMTBA; 1). In 0.25 M phosphoric acid medium, which greatly increases the selectivity, lead reacts with DBMTBA to form a 1:2 blue complex, which shows maximum absorption at 646 nm.

Simple, selective and sensitive spectrophotometric determination of fenitrothion using novel chromogenic reagent.

A facile, rapid and sensitive spectrophotometric method was developed for the determination of fenitrothion in its formulations, water, food grain and agriculture soil samples with newly synthesised reagent. The method was based on the alkaline hydrolysis of fenitrothion pesticide and resultant hydrolysed product of fenitrothion was coupled with diazotised 4,4'-methylene-bis-(p-amino-3'-hydroxybenzanilide) in basic medium to give orange coloured product having lambdamax 480 nm. The formation of coloured derivatives with the coupling agent is instantaneous and stable for 48 h.

Novel analytical reagent for the application of cloud-point preconcentration and flame atomic absorption spectrometric determination of nickel in natural water samples.

Cloud-point extraction was applied as a preconcentration of nickel after formation of complex with newly synthesized N-quino[8,7-b]azin-5-yl-2,3,5,6,8,9,11,12octahydrobenzo[b][1,4,7,10,13]pentaoxacyclopentadecin-15-yl-methanimine, and later determined by flame atomic absorption spectrometry (FAAS) using octyl phenoxy polyethoxy ethanol (Triton X-114) as surfactant. Nickel was complexed with N-quino[8,7-b]azin-5-yl-2,3,5,6,8,9,11,12octahydrobenzo[b][1,4,7,10,13]pentaoxacyclopentadecin-15-yl-methanimine in an aqueous phase and was kept for 15 min in a thermo-stated bath at 40 degrees C. Separation of the two phases was accomplished by centrifugation for 15 min at 4000 rpm.

Cloud point extraction of palladium in water samples and alloy mixtures using new synthesized reagent with flame atomic absorption spectrometry (FAAS).

The present paper outlines novel, simple and sensitive method for the determination of palladium by flame atomic absorption spectrometry (FAAS) after separation and preconcentration by cloud point extraction (CPE). The cloud point methodology was successfully applied for palladium determination by using new reagent 4-(2-naphthalenyl)thiozol-2yl azo chromotropic acid (NTACA) and hydrophobic ligand Triton X-114 as chelating agent and nonionic surfactant respectively in the water samples and alloys. The following parameters such as pH, concentration of the reagent and Triton X-114, equilibrating temperature and centrifuging time were evaluated and optimized to enhance the sensitivity and extraction efficiency of the proposed method.

Preconcentration technique for the determination of trace elements in natural water samples by ICP-AES.

A procedure was developed for the determination of Cd, Cu, Zn, Co, Ni, Mn, Pb and Mo in water samples by inductively coupled plasma atomic emission spectrometry (ICP-AES) after preconcentration on a morpholine dithiocarbamate (mor-DTC) supported by bagasse (Saccharam aphisinaram). The sorbed elements were subsequently eluted with 4,M HNO3 and the acid eluates were analysed by ICP-AES. The influence of various parameters such as pH, flow rate of sample, eluent concentration, volume of the sample and volume of eluent were investigated to enhance the sensitivity of the present method.

Facile and sensitive spectrophotometric determination of carbosulfan in formulations and environmental samples.

Facile, selective and sensitive spectrophotometric method has been developed for the determination of carbosulfan in insecticidal formulations, fortified water, food grains, agriculture wastewater and soil samples with newly synthesized reagents. The method was based on acid and alkaline hydrolysis of the carbosulfan pesticide, and the resultant hydrolysis product of carbosulfan was coupled with 2,6-dibromo-4-methylaniline to give a yellow color product with lambda(max) of 464 nm or interaction with 2,6-dibromo-4-nitroaniline to produce yellow colored product with lambda(max) of 408 nm or coupling with 2,4,6-tribromoaniline to form red colored product has a lambda(max) of 471 nm. Under optimal conditions, Beer's law range for 2,6-dibromo-4-methylaniline (DBMA) was found to be 0.

Development of simple and sensitive spectrophotometric method for the determination of bendiocarb in its formulations and environmental samples.

Facile, selective and sensitive spectrophotometric method has been developed for the determination of bendiocarb in its insecticidal formulations, fortified water, food grains, agriculture wastewater and agriculture soil samples with prepared reagents. The method was based on alkaline hydrolysis of the bendiocarb pesticide, and the resultant hydrolysis product of bendiocarb was coupled with 2,6-dibromo-4-methylaniline to give a yellow color product with lambda max of 457 nm or coupling with 2, 6-dibromo-4-nitroaniline to produce a red colored product with lambda max of 474 nm or coupling with 2, 4, 6-tribromoaniline to form orange red colored product has a lambda max of 465 nm. Under optimal conditions, Beer's law range for 2, 6-dibromo-4-methylaniline (DBMA) was found to be 0.

Spectrophotometric determination of V(V) in environmental, biological, pharmaceutical and alloy samples by novel oxidative coupling reactions.

A Novel, rapid, sensitive and selective reactions are developed for spectrophotometric determination of trace amounts of vanadium (V) in environmental, biological, pharmaceutical and alloy samples was studied. The methods were based on interactions of 4-bromophenyl hydrazine (4-BPH) with N-(1-naphthyl ethylenediamine dihydrochloride (NEDA) in the presence of vanadium in acidic medium (acetate buffer of pH 3.0) to give violet colored derivative or on the oxidation of 4-bromophenyl hydrazine by vanadium in basic medium and coupling with chromotropic acid (CA) to yield red color derivative.

Facile and sensitive spectrophotometric determination of synthetic pyrithroids in their formulations, water and grain samples.

A novel reagent was introduced for the facile and sensitive spectrophotometric determination of synthetic pyrethroids in their formulations (fenvalerate, cypermethrin and decamethrin), water and grain samples. These methods were based on the hydrolysis of synthetic pyrethroids under the alkaline conditions to form respective aldehyde groups. These groups were condensation with 3-methyl-2-benzothiazolinone hydrochloride (MBTH) to yield color derivatives having lambda(max) at 520 nm for fenvalerate, 516 nm for cypermethrin and 512 nm for decamethrin.

Extractive spectrofluorometric determination of quinalphos using fluorescein in environmental samples.

A simple, sensitive, convenient and low cost spectrofluorometric technique for determination of quinalphos is described. Quinalphos is decomposed with sodium ethoxide. Resultant sodium diethyl thiophosphate (Na-DETP) is extracted with a cationic fluorescein as ion pair complex into 1-chloro-2-nitrobenzene.

Studies of selenium in environmental samples and synthetic mixtures by spectrophotometry.

A rapid, highly sensitive and selective spectrophotometric method for the determination of traces of selenium(IV) is described. The method is based on oxidation of p-nitroaniline by selenium(IV) followed by coupling reaction with N-(1-naphthalene-1-yl)ethane-1,2-diamine dihydrochloride (NEDA) in neutral medium to give red colored derivative with lambda(max) 515 nm and is stable for more than 10 days at 35 degrees C. Beer's law is obeyed for selenium(IV) in the concentration range of 0.

The facile flow-injection spectrophotometric detection of gold(III) in water and pharmaceutical samples using 3,5-dimethoxy-4-hydroxy-2-aminoacetophenone isonicotinoyl hydrazone (3,5-DMHAAINH).

A simple, sensitive and rapid flow-injection spectrophotometric method was developed for the determination of trace amounts of Au(III) in aqueous dimethylformamide (DMF). The method is based on formation of Au(III)-(3,5-DMHAAINH)3 complex. The optimum conditions for the chromogenic reaction of Au(III) with 3,5-DMHAAINH is studied and the colored (reddish brown) complex is selectively monitored at lambda(max) 490 nm at pH 6.

The determination of nickel(II) after on-line sorbent preconcentration by inductively coupled plasma atomic emission spectrometry using Borassus Flabellifer inflorescence loaded with coniine dithiocarbamate.

A procedure was developed for the determination of nickel(II) in water samples by inductively coupled plasma atomic emission spectrometry (ICP-AES) after preconcentration on coniine dithiocarbamate (CDC) supported by Borassus Flabellifer inflorescence. The sorbed element was subsequently eluted with 0.4M nitric acid and the acid eluates are analysed by ICP-AES.