Separation and Preconcentration of Trace Amounts of Manganese and Nickel from Natural Water Samples by a Diimine Derivative Schiff Base-Coated Silica-Gel Minicolumn

An efficient method for preconcentration of trace amounts of Mn (II) and Ni (II) ions by using a minicolumn (10 mm × 30 mm i.d.) filled with a diimine derivative Schiff base on silica-gel has been reported. The retained analytes on the column were recovered with 5 mL of mixture of nitric acid 5 mol L−1 and methanol (1 : 1) and were determined by a flame atomic absorption spectrometer. Different factors including pH of sample solution, sample volume, amount of sorbent, eluent volume, and interference of other ions have been studied and the optimized conditions developed were utilized for the trace determination of Mn (II) and Ni (II) in natural water samples. The recoveries for the analytes under the optimum working conditions were higher than 98%. The relative standard deviations of the determinations (10 replicate analyses) at 25 μg L−1 of Mn (II) and Ni (II) were 2.5% and 2.3%, respectively. The limit of the detection (3s, n=10) for analytes were found to be 0.20 μg L−1 for Mn (II) and 0.15 μg L−1 for Ni (II). The proposed method was applied to the analysis of natural water samples with satisfactory results

A novel separation/preconcentration procedure using in situ sorbent formation microextraction for the determination of cobalt (II) in water and food samples by flame atomic absorption spectrometry

AbstractA new, simple, low cost, and rapid solid phase extraction method, that was named in situ sorbent formation microextraction (ISSFME), was developed for the selective separation and determination of cobalt (II) in various water and food samples. In the present work, cetyltrimethylammonium bromide was used as a cationic surfactant, perchlorate ion as an ion-pairing agent, and 2-nitroso-1-naphthol as a complexing agent. After extraction, the concentration of cobalt was determined by flame atomic absorption spectrometer. Several variables that affect the extraction efficiencies were investigated and optimized. Under the optimized conditions, the limit of detection was 0.8μgL−1 with a preconcentration factor of 50. The RSD for 10 replicate measurements of 50μgL−1 of cobalt was 2.3%. The accuracy and applicability of the method were tested by evaluating the amount of cobalt in water certified reference materials and various water and food samples

Separation and Preconcentration of Trace Amounts of Manganese and Nickel from Natural Water Samples by a Diimine Derivative Schiff Base-Coated Silica-Gel Minicolumn

An efficient method for preconcentration of trace amounts of Mn (II) and Ni (II) ions by using a minicolumn (10 mm × 30 mm i.d.) �lled with a diimine derivative Schiff base on silica-gel has been reported. e retained analytes on the column were recovered with 5 mL of mixture of nitric acid 5 mol L −1 and methanol (1 : 1) and were determined by a �ame atomic absorption spectrometer. Different factors including pH of sample solution, sample volume, amount of sorbent, eluent volume, and interference of other ions have been studied and the optimized conditions developed were utilized for the trace determination of Mn (II) and Ni (II) in natural water samples. e recoveries for the analytes under the optimum working conditions were higher than 98%. e relative standard deviations of the determinations (10 replicate analyses) at 25 g L −1 of Mn (II) and Ni (II) were 2.5% and 2.3%, respectively. e limit of the detection (3s, 1 for analytes were found to be 0.20 g L −1 for Mn (II) and 0.15 g L −1 for Ni (II). e proposed method was applied to the analysis of natural water samples with satisfactory results

Homogeneous Liquid-Liquid Extraction Method for Selective Separation and Preconcentration of Trace Amounts of Palladium

Abstract: A simple and effective homogeneous liquid-liquid extraction method for selective separation, preconcentration and spectrophotometric determination of palladium(II) ion was developed by using a ternary component system (water / tetrabutylammonium ion (TBA -2 mol L -1 and pH= 3.0), a preconcentration factor 10 was obtained for 10 mL of sample. The analytical curve was linear in the range of 2-100 ng mL -1 and the limit of detection was 0.4 ng mL -1 . The relative standard deviation was 3.2% (n=10). Accuracy and application of the method was estimated by using test samples of natural and synthetic water spiked with different amounts of palladium(II) ion. The method is very simple and inexpensive

Ligand-less Rapidly Synergistic Cloud Point Extraction as an Efficient Method for the Separation and Preconcentration of Trace Amounts of Lead from Food and Water Samples

A simple rapidly synergistic cloud point extraction procedure has been developed for the separation and preconcentration of trace amounts of lead from food and water samples by flame atomic absorption spectrometry (FAAS). Rapidly synergistic cloud point extraction (RS-CPE) greatly simplified and accelerated the procedure of traditional cloud point extraction (CPE). This method was accomplished in room temperature in 1 min. Non-ionic surfactant Triton X-114 was used as extractant. Octanol worked as cloud point revulsant and synergic reagent which lowered the cloud point temperature of Triton X-114 and assisted the subsequent extraction process. Some parameters that influenced cloud point extraction and subsequent determination were evaluated in detail, such as sample pH, amounts of octanol, amounts of Triton X-114, type of diluting solvent, extraction time and ionic strength, as well as interferences. Under optimized conditions (pH 8.5, octanol: 10 µL, Triton X-114: 0.04% w/v and diluting solvent: 1 mol L-1 HNO3 in methanol), an enhancement factor of 40 could be obtained, and the detection limit (LOD) for lead was 1.6 µg L-1. Relative standard deviation for ten replicate determinations of the standard solution containing 100 µg L-1 lead was 2.1%. The proposed method was applied for the determination of lead in food (spinach, rice and black tea bag) and water samples and satisfactory results were obtained

Determination of Trace Amounts of Palladium in Water Samples by Graphite Furnace Atomic Absorption Spectrometry after Dispersive Liquid-Liquid Microextraction

A simple, rapid, and powerful microextraction technique was used for determination of palladium (II) ion in water samples using dispersive liquid-liquid microextraction (DLLME) followed by graphite furnace atomic absorption spectrometry (GF AAS). The different variables affecting the complexation and extraction conditions such as extraction and disperser solvent type, extraction time, pH, and concentration of chelating agent were optimized. Under the optimum conditions, the calibration graph was linear in the ranges of 0.05–1 μg L−1 with detection limit of 0.02 μg L−1. The precision (RSD %) for ten replicate determination at 0.2 μg L−1 of palladium was better than 3.5% and the enrichment factor 166.5 was obtained from only 5.0 mL of sample. Under the presence of foreign ions, no significant interference was observed. Finally, accuracy and application of the method were estimated by using test samples of natural waters spiked with different amounts of palladium

Kinetic-Spectrophotometric Determination of Iodide Based on its Inhibitory Effect on the Decolorization Reaction of Methyl Orange

A simple, sensitive, rapid and reliable method has been developed for spectrophotometric determination of iodide based on its inhibition effect on the redox reaction between bromate and hydrochloric acid. The decolorization of methyl orange by the reaction products was used to monitor the reaction spectrophotometrically at 525 nm. The variables affecting the rate of the reaction were investigated. Under the optimum conditions, the limit of detection is 1.5 × 10-7 mol L-1 and calibration range is 2.0 × 10-6–1.3 × 10-4 mol L-1 of iodide. The linearity range of the calibration graph is depends on bromate concentration. The relative standard deviation of ten-replication determination of 8.2 × 10-5 mol L-1 iodide was 1.4%. The proposed method was applied to the determination of iodide in natural water samples with satisfactory results

Development of an in situ solvent formation microextraction and preconcentration method based on ionic liquids for the determination of trace cobalt (II) in water samples by flame atomic absorption spectrometry

A simple in situ solvent formation microextraction (ISFME) methodology based on the application of ionic liquid (IL) as an extractant solvent and sodium hexafluorophosphate (NaPF6) as an ion-pairing agent was proposed for the preconcentration of the trace levels of cobalt ions. In this method cobalt was complexed with 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol (5-Br-PADAP) and extracted into an ionic liquid phase. After phase separation, the enriched analyte in the final solution is determined by flame atomic absorption spectrometry (FAAS). Some effective factors that influence the microextraction efficiency were investigated and optimized. Under the optimum experimental conditions, the limit of detection and the enrichment factor were 0.97 μg L−1 and 50, respectively. The relative standard deviation (R.S.D.) was obtained as 2.4%. The proposed method was assessed through the analysis of certified reference water and recovery experiments

Determination of Ni(II) and Co(II) by FAAS after preconcentration on modified alumina column

1086-1088A method for the determination of Co(II) and Ni(II) by flame atomic absorption spectrometry after preconcentration on a minicolumn of alumina modified with sodium dodecyl sulfate and schiff's base has been developed. Effects of pH, flow rate, volume of sample solution, capacity of sorbent and interference of foreign ions on the recovery of the analytes have been investigated. Under the optimized conditions (pH = 5; flow rate =15 ml min-1), recovery was greater than 98%. The relative standard deviations (10 replicate analyses) at the 50 ng ml-1 level are 2.5% for Ni(II) and 3.2% for Co(II) and the corresponding limits of detection (3s, n =10) are 0.014 ngml-1 for Ni(II) and 0.007 ng ml-1  for Co(II). The method has been applied for the determination of Ni(II) and Co(II) in natural waters and standard materials