For the very first time, a microemulsion system in the Winsor II (WII) equilibrium was applied in a sample preparation method for extraction and pre-concentration in the determination of Pb, Cd, Co, ...Tl, Cu and Ni, in natural waters by high resolution continuum source atomic absorption spectrometry (HR-CS AAS). The method was optimized using the graphite furnace atomization. A simplex-centroid design for determine optimum extraction condition (77.5% aqueous phase, 5% of the oil phase, and 17.5% cosurfactant/surfactant ratio - C/S = 4) was applied. The optimized time for the sample preparations was around 30 min. The analytical performance of the optimized method using HR-CS GF AAS showed that the detection limits were: 0.09, 0.01, 0.06, and 0.05 μg L−1 for determination of Pb, Cd, Tl, and Co, respectively and the enrichment factors were between 6 and 19, considered excellent for all analytes. The RSD values were lower than 5%, demonstrating the good precision of the proposed method. When the optimized method was applied using the HR-CS F AAS, the sensibility increased 9 to 12 times for Cu and Ni, respectively. The analytical method was successfully applied for the determination of analytes in Certified Reference Material and real samples for natural waters such as Brackish water (recovery between 107 and 112%), Saline water (recovery between 83 and 94%), Produced water from oil industry (recovery between 98 and 110%) and Fresh water (recovery 80 and 87% to Cu and Ni respectively). All the results confirming the accuracy of the analytical method proposed. The repeatability of the measurements has been better 5% (n = 3), for all elements.
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•A new method using microemulsion in Winsor II equilibrium applied in analytical chemistry.•A simplex-centroid experimental design was used as a multivariate method to assess the optimal efficiency point.•Toxic metals such as Pb, Cd, Co and Tl were analyzed by HR-CS GF AAS with very low limits of detection.•The values of enhancement factors indicate that the method proposed enhances sensitivity at least 6 times.•The surfactant of the system was prepared from materials widely available in the northeast from Brazil.•The proposed method generates minimal waste, which corroborates its eco-friendly status.
In the past, many types of researches have been performed to allow multi-element determinations using atomic absorption spectrometry. The first spectrometers developed for this purpose were proposed ...in the 1970s, using flame and furnace atomizers.
In the early 2000s, a spectrometer equipped with software that allows a fast selection of the hollow cathode lamps was introduced commercially. This equipment operates in a sequential mode, and it enables the determination of up to 16 elements. Many publications have reported its performance.
Over the years, many spectrometers were built adding new technologies, but they were discontinued due to low sensitivity, difficulty for background corrections, etc. However, all the efforts of the past have contributed to the development and consolidation of the high-resolution continuum source atomic absorption spectrometry (HR-CS AAS) using flame and furnace atomizers. This technique allows the establishment of sequential and simultaneous methods for determinations of many elements with high sensitivity and efficient background correction.
simultaneous determination of tin, iron and candium using HR-CS GFAAS. Display omitted
•A historical and current review of the AAS as a multi-element technique have been presented.•A comparison between some spectrometric techniques has been shown.•Applications of an AAS spectrometer with line source as multi-element equipment have been shown.•Advantages and applications of the HR-CS AAS as a multi-element technique have been described in detail.•Use of internal standardization in the AAS has been discussed and some results presented.
Atomic absorption spectrometry (AAS) is one of the most widely used and available methods for analysis of substances and materials. It allows one to determine about 70 elements from the periodic ...table and is characterized by rapidity, high accuracy and sensitivity, as well as simplicity of analytical techniques. A feature of AAS is simultaneous determination of only one element due to the use of a measurement design with a line source (hollow-cathode lamps, high-frequency electrodeless lamps, optical quantum generators, etc.). To make AAS more competitive, the first commercially available continuum source atomic absorption spectrometer was designed in 2004. Unique analytical capabilities of the new instruments found application first of all in the analysis of food, pharmaceuticals, waste and drinking water, oil and petrochemicals, biological objects, etc. This review covers publications on the application of continuum source AAS in analytical chemistry and provides a development outlook of the method.
Sulfur is one of the most abundant elements on the crust of Earth, and it is an essential element for animals and plants. In addition to playing a vital role in living organisms, it has a very ...important use in industry as an ingredient in some chemicals, fertilizers, fungicides, pesticides, pharmaceuticals, and so on. There are limit values for sulfur content in many matrices, which explains why it is important to determine sulfur contents.
This review aims to give an overview of historical development and importance of sulfur determination by high-resolution continuum source atomic absorption spectrometry (HR CS AAS). We primarily focus on recent applications and their optimized parameters for the determination of sulfur in many matrices. The application of sulfur determination by HR CS AAS is evaluated and some scientific properties of sulfur determination by HR CS AAS are also presented.
•Different analytical methods for the determination of sulfur are discussed.•Sulfur analysis by high-resolution atomic absorption spectrometers is discussed.•Factors that influence each technique are discussed.•Advantages and limitations of each technique are addressed.
Air–assisted liquid–liquid microextraction is a sample preparation method having high extraction recoveries and enrichment factors with associated low organic solvent consumption. This method has ...found wide acceptance among researchers due to different advantages, such as simplicity, low cost, and accessibility in most analytical laboratories. The present review focuses on developments of the method since its invention in 2012. The utility of developed method in conjunction with gas chromatography, high performance liquid chromatography, atomic absorption spectrometry, and ultraviolet–visible spectrometry is described. The use of different solvents like ionic liquids, deep eutectic solvents, and organic solvents are considered. Also, derivatization and centrifuge–less methods are reviewed. The survey of literature showed that the method can be used as an efficient and powerful technique for extraction of different compounds. The published reports on determination of the extracted analytes by the method are critically reviewed. Future trends are also mentioned.
•AALLME was introduced and its principles were discussed.•AALLME coupled with different analytical instruments were fully mentioned and discussed.•Advantages and disadvantages of various AALLME methods were reviewed.
A new liquid phase microextraction method based on deep eutectic solvent microextraction was developed for separation and preconcentration of lead, cobalt, nickel and manganese from edible oil ...samples like sunflower oil, baby oil, trout, waste frying oil and syrup-soaked pastry oil. A choline chloride deep eutectic solvent was used for microextraction. After extraction, analytical concentrations were determined by flame atomic absorption spectrometry. Effects of analytical parameters such as type and volume of deep eutectic solvent, sample volume, and temperature on extraction efficiency of lead, cobalt, nickel and manganese were optimized. The recoveries were generally >95%. The relative standard deviation (RSD, %, n = 7) of 50 μg/ L of analyte elements was in the range of 0.9–4.3%. Accuracy of presented microextraction method was checked by addition-recovery studies to oil samples. The presented deep eutectic solvent microextraction method was finally applied to edible oil samples and waste oils with different properties for the determination of analyte contents.
•A green deep eutectic solvent liquid phase microextraction method has been developed for metal ions in oil samples.•The effects of analytical parameters were systematically investigated and optimized.•Accuracy of microextraction method was checked by addition-recovery studies to oil samples.
The development of miniature, sensitive, high throughput, and in-situ analytical instruments has been becoming developing field of modern analytical chemistry. Due to its unique advantages such as ...easy operation, simple configuration, ambient working temperature and pressure, low power consumption, and miniature dimension, dielectric barrier discharge (DBD) has always been a hot topic in analytical chemistry. This review gives an overview of miniature DBD application in analytical atomic spectrometry, starting with an introduction to its geometrical configuration and ionization mechanisms. Then, its applications such as excitation or atomization sources in atomic emission spectrometry (AES), atomic absorption spectrometry (AAS) and atomic fluorescence spectrometry (AFS) are reviewed. Also, its application as vapor generation system in atomic spectrometry is discussed.
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•The application of miniature DBD in analytical atomic spectrometry is discussed.•The DBD configuration and plasma formation process are introduced.•The methodological development and analytical performance are reviewed.•The future development trend of miniature DBD in atomic spectrometry is presented.
In this work, a new cloud point extraction (CPE) procedure was developed for the separation and preconcentration of lead(II), cobalt(II), and copper(II) in various water and food samples. Complexes ...of metal ions with 1-Phenylthiosemicarbazide (1-PTSC) were extracted into the surfactant-rich phase of octylphenoxypolyethoxyethanol (Triton X-114) from samples. After phase separation, the enriched analytes were determined by flame atomic absorption spectrometry (FAAS). Factors affecting cloud point extraction, such as pH, reagent and surfactant concentrations, temperature, and incubation time were evaluated and optimized. The interference effect of some cations and anions was also studied. After optimization of the CPE conditions, the preconcentration factor of 25 and the limits of detection (L.O.D.) obtained for lead(II), cobalt(II), and copper(II) based on three sigma (
n
=
20) were 3.42, 1.00, and 0.67
μg L
−1, respectively. The method presented precision (R.S.D.) between 1.7% and 4.8% (
n
=
7). The presented preconcentration procedure was applied to the determination of metal ions in reference standard materials (SRM 1515 Apple leaves and GBW 07605 Tea) and some real samples including tap water, spring water, sea water, canned fish, black tea, green tea, tomato sauce and honey.
A novel separation–preconcentration procedure based on ionic liquid dispersive liquid–liquid microextraction of traces lead as pyrrolidinedithiocarbamate chelate has been developed. ...1-Hexyl-3-methylimidazolium hexafluorophosphate as ionic liquid was used for extraction of lead pyrrolidinedithiocarbamate chelate. After phase separation, the enriched analyte in the final solution is determined by flame atomic absorption spectrometry (FAAS). The effects of pH, amounts of ligand, amounts of 1-hexyl-3-methylimidazolium hexafluorophosphate, sample volume etc. on the recoveries of lead ions were investigated. The influences of some cations and anions on the recoveries of lead were also examined. The preconcentration factor was calculated as 40 at the sample volume of 20ml. The detection limit for lead ions was 1.5μg/l. The validation of the presented method was performed by the analysis of TMDA-51.3 fortified water. The method was applied to natural water samples.
