Quartz Tube-flame Atomic Absorption Spectrophotometry Research Articles

Determination of trace cadmium in saliva samples using spray assisted droplet formation-liquid phase microextraction prior to the measurement by slotted quartz tube-flame atomic absorption spectrophotometry

BackgroundAn effective, green and rapid analytical strategy namely the simultaneous spray assisted droplet formation-liquid phase microextraction (S-SADF-LPME) method was developed for the determination of trace quantity of cadmium in saliva samples by using the slotted quartz tube-flame atomic absorption spectrophotometry (SQT-FAAS). By the developed method, external dispersive solvent usage for droplet formation was reduced to obtain a more environmental-friendly method. MethodsMethod consists of a simultaneous complexing and extraction step, which was based on spraying an extraction solvent containing a solid ligand into the aqueous sample solution, forming fine droplets without the use of dispersive solvent. The procedure was implemented using a customized, cost effective and portable spray apparatus to minimize the consumption of reagent, analysis time and operation steps. Thus, this methodology ensures better repeatability and accuracy while minimizing the relative errors caused by the experimental steps. Parameters including the buffer amount, extractant/ligand concentration, extraction solvent type, extraction/ligand solution volume, spraying number and vortex period were systemically optimized to lower the detection limit. ResultsUnder the optimal extraction conditions, 96.9-folds enhancement in the detection power of the traditional FAAS was achieved. The limit of detection and limit of quantification values of presented method were calculated to be 0.65 and 2.17 ng mL−1, respectively. Accuracy and applicability of the optimized method was investigated by collecting saliva samples from smokers. Satisfactory percent recovery values wereachieved for cadmium with a low standard deviation in the acceptable range of 84.9–109.6 %. ConclusionThe developed dispersive solvent-free S-SADF-LPME technique presents a fast, simple, cost-effective and eco-friendly microextraction method based on the use of an easily accessible and functional spray apparatus.

Preconcentration of tellurium using magnetic hydrogel-assisted dispersive solid-phase extraction and its determination by slotted quartz tube-flame atomic absorption spectrophotometry

Preconcentration of tellurium using magnetic hydrogel-assisted dispersive solid-phase extraction and its determination by slotted quartz tube-flame atomic absorption spectrophotometry

Accurate and sensitive determination of cobalt in urine samples using deep eutectic solvent-assisted magnetic colloidal gel-based dispersive solid phase extraction prior to slotted quartz tube equipped flame atomic absorption spectrometry

In this study, a colloidal gel of magnetic Fe3O4 nanoparticles was used in the development of a simple and accurate dispersive solid phase extraction method for the extraction/preconcentration of trace levels of cobalt ions in urine samples. The eluted cobalt ions were determined by slotted quartz tube-flame atomic absorption spectrophotometry (SQT-FAAS). The effects of the type and volume of buffer solution, volume of magnetic colloidal gel, type and period of mixing, concentration and volume of the eluent were investigated and optimized to obtain the best experimental outputs. Under the optimum conditions, the limits of detection and quantification were found as 4.6 and 15 ng mL−1, respectively. The developed method provided a 61.5 folds enhancement in the detection power of the flame atomic absorption spectrophotometry. Method validation was performed by spiking experiments using matrix matching method. The percent recoveries were found to be close to 100% for the spiked samples, which validate the accuracy and the applicability of the developed method to the urine samples.

An accurate and sensitive effervescence-assisted liquid phase microextraction method for the determination of cobalt after a Schiff base complexation by slotted quartz tube-flame atomic absorption spectrophotometry in urine samples.

In this study, an accurate analytical method development for cobalt determination in urine samples was described. The method is based on the mass transfer of the target analytes to the organic phase from the aqueous phase by the dispersing extractant throughout the solution with the aid of CO2 bubbles prior to sample measurement by using a slotted quartz tube flame atomic absorption spectrophotometer. An extractor (1-decanol) dropped effervescent tablet (anhydrous sodium carbonate and sodium dihydrogen phosphate dihydrate mixture) was used in order to separate/preconcentrate cobalt after complexation of cobalt ions in aqueous solution with the Schiff base ligand. The parameters affecting the extraction output such as complexing conditions (pH, ligand concentration, and volume) and extraction conditions (extraction solvent type and volume, extraction temperature, and heating duration, NaOH volume and mixing period) were optimized to lower the detection limit. The limit of detection and quantification values under optimized experimental and instrumental conditions were determined as 3.7 μg L-1 and 12 μg L-1, respectively with high linearity with respect to the dynamic range between 15 and 300 μg L-1. The enhancement factor obtained with the developed method was calculated as 83 fold. The pretreatment process was applied to urine samples in order to test the convenience of the developed method in urine samples for the determination of cobalt at low levels. The high percentage recovery results of 96-97% for four different concentrations of spiked urine samples indicated the proposed method's sufficient sensitivity for analyte determination in such a complex matrix.

Ultrasonic assisted glass bead loaded gas liquid separator-photochemical vapor generation-T-shaped slotted quartz tube-flame atomic absorption spectrophotometry system for antimony determination in tap water and wastewater samples

In this study, optimization and validation of ultrasonic assisted glass bead loaded gas liquid separator-photochemical vapor generation-T-shaped slotted quartz tube-flame atomic absorption spectrophotometry (UA-GLS-PVG-T-SQT-FAAS) system was performed for the determination of antimony in real samples. Volatile derivatives of antimony were generated and separated from liquid matrix by combination of a UV photoreactor and gas–liquid separation. Optimization of all variable parameters which effect volatile compound generation and separation efficiency such as low molecular weight organic acid type and concentration, ultraviolet irradiation period, gas–liquid separator design, carrier gas flow rate and sample volume were evaluated one at a time keeping the others constant. Limit of detection and quantification were calculated as 47 and 157 µg L–1, respectively. Detection power of the developed method was enhanced about 58 folds compared to conventional FAAS system over LOD comparison. In addition, applicability/accuracy of the developed method was checked by spiking experiments in tap and wastewater samples and percent recovery results were found in the range 83.4–106.4%.

A new microextraction method for trace nickel determination in green tea samples: Solventless dispersion based dispersive liquid-liquid microextraction combined with slotted quartz tube- flame atomic absorption spectrophotometry

In this study, a simple and novel analytical approach was developed in order to determine nickel at trace levels. For this purpose, a dispersive liquid-liquid microextraction (DLLME) method based on solventless dispersion of extraction solvent was developed to separate/preconcentrate nickel from aqueous solution. Combination of the DLLME method with slotted quartz tube-flame atomic absorption spectrophotometry (SQT-FAAS) lowered the analyte’s detection limit. In the DLLME method, the extraction solvent was dispersed into aqueous solution by generating fine droplets through air assisted spraying in order to reduce organic solvent consumption and avoid relative error by reducing multiple operation steps. Complexation of nickel(II) was done by using a Schiff Base synthesized from the reaction between 3,5- dibromosalicylaldehyde and 2-aminophenol. All experimental parameters were optimized comprehensively by the step-by-step approach in order to determine optimum conditions to get maximum absorbance values. Under the optimum conditions, analytical performance values were examined, and limit of detection values were obtained as 286 ng mL-1 for FAAS, 137 ng mL-1 for SQT-FAAS, 7.9 ng mL-1 for DLLME-FAAS and 3.9 ng mL-1 for DLLME-SQT-FAAS. The enhancement in detection power was obtained as 82-folds over the detection limit of the conventional FAAS system. Chinese green tea sample was used in recovery studies to check applicability and accuracy of the developed method. Recovery results were close to 100 % with low standard deviation values (n = 4) and this showed that the method appropriate for the selected matrix.

Zirconium nanoparticles based ligandless dispersive solid phase extraction for the determination of antimony in bergamot and mint tea samples by slotted quartz tube-flame atomic absorption spectrophotometry

A sensitive and effective analytical method was developed to preconcentrate antimony from the bergamot and mint tea samples for its determination at trace levels by slotted quartz tube-flame atomic absorption spectrophotometry (SQT-FAAS) system. The developed method was based on vortex assisted ligandless dispersive solid phase extraction (VA-LDSPE) using zirconium nanoparticles (Zr-NPs) as sorbent material for the adsorption of the target analyte. All variables involved in the DSPE method (pH value, nanoparticle amount, mixing and eluent type/volume) were optimized to boost the absorbance signal of antimony. Using the optimal parameters, the method provided satisfactory detection and quantification limits of 8.0 and 26.8 μg L−1, respectively. A 180 folds enrichment factor was achieved by the developed method when compared with the detection power of the FAAS. Linear range of the proposed method was found to be 30–250 μg L−1, with a coefficient of determination value of 0.9992. The established Zr-NPs-VA-LDSPE-SQT-FAAS method was successfully implemented to bergamot tea samples in order to check accuracy and applicability. The obtained recovery values ranged between 93–102%, and this demonstrated that the complex matrices tested did not affect the accuracy of quantifying antimony.

Zirconium nanoparticles based dispersive solid phase extraction prior to slotted quartz tube-flame atomic absorption spectrophotometry for the determination of selenium in green tea samples

In this study, a novel, easy, rapid and green zirconium nanoparticles (Zr-NPs) based dispersive solid phase extraction (DSPE) method is presented for the precise and sensitive determination of selenium by slotted quartz tube-flame atomic absorption spectrophotometry (SQT-FAAS). Influential parameters of the extraction procedure were optimized by altering one parameter while keeping the other parameters constant. The optimum conditions were selected as 10mg of Zr-NPs, 75s vortex period, and 200µL of concentrated HCl for 30mL of sample/standard solution. The linear range of the developed method was found to be between 25 and 100µg/L, and the respective limits of detection and quantification were 5.3 and 18µg/L. About 415 folds enhancement in detection power was achieved by the optimized method relative to the conventional FAAS. Green tea samples were spiked and used for recovery experiments and the results obtained were between 92 and 102%.

Zirconium nanoparticles based solid phase extraction-slotted quartz tube-flame atomic absorption spectrophotometry for the determination of cadmium in wastewater samples and evaluation of green profile

ABSTRACT In this paper, a novel zirconium nanoparticles (Zr-NPs)-based solid-phase extraction (SPE) strategy was established for the accurate and sensitive determination of cadmium at trace levels prior to slotted quartz tube-flame atomic absorption spectrophotometry (SQT-FAAS) system. Zr-NPs were synthesised with a simple and fast method and utilised as adsorbents for the extraction of the analyte from aqueous samples. The primary factors affecting the extraction recovery such as nanoparticle amount, mixing type and period, type and volume of eluent were optimised by single variant experiments to obtain optimal extraction conditions. Under the optimised conditions, the calibration plot of the method showed a linear range of 2.0–25 µg L−1 with a regression coefficient of 0.9993. The limit of detection and limit of quantification obtained were 0.44 and 1.46 µg L−1, respectively. In order to make sure whether the developed method is applicable to complex matrices, an extraction procedure was successfully applied to wastewater samples. For this purpose, spiked recovery studies were performed at three different cadmium concentration. The per cent recoveries were obtained between 96.1% and 100.7% with low per cent relative standard deviations. Thus, the proposed method was validated and confirmed its high accuracy and precision with satisfactory recoveries.

Peristaltic pump-assisted zirconium nanoparticle-based pipette-tip solid phase extraction for the determination of cobalt by slotted quartz tube-flame atomic absorption spectrophotometry

In this work, a novel, efficient, simple and green solid phase extraction method based on a pipette tip filled with zirconium nanoparticles was developed for the sensitive determination of cobalt in soil samples via slotted quartz tube-flame atomic absorption spectrophotometry.

Determination of palladium in soil samples by slotted quartz tube-flame atomic absorption spectrophotometry after vortex-assisted ligandless preconcentration with magnetic nanoparticle-based dispersive solid-phase microextraction.

In this study, a rapid and effective dispersive solid-phase microextraction (d-SPME) method was developed to preconcentrate Pd from aqueous extract of soil samples by slotted quartz tube-flame atomic absorption spectrometry (SQT-FAAS). The unique properties of magnetic nanoparticles (MNPs) were used to directly isolate Pd from the sample solutions without the need for complexation. Significant parameters of the extraction method such as magnetic nanoparticle type and amount, pH and amount of buffer solution, amount of eluent, and mixing type and period were optimized together with other instrumental parameters to boost the absorbance signal of Pd. An SQT was fitted onto the burner head to boost the interaction between Pd atoms and hollow cathode lamp radiation to enhance absorbance signals. The limit of detection (LOD) and limit of quantification (LOQ) values for Pd determined (d-SPME-MNP-SQT-FAAS) were 6.4 and 21.4ng/mL, respectively. The percentage relative standard deviation of the developed method was calculated as 6.6%. The method was applied to soil samples taken from the campus area and spiked recovery experiments were performed to evaluate the method's accuracy/applicability. Satisfactory percent recovery results (90-101%) were obtained for different spiked concentrations and this proved the accuracy/applicability of the method.

Combination of stearic acid coated magnetic nanoparticle based sonication assisted dispersive solid phase extraction and slotted quartz tube-flame atomic absorption spectrophotometry for the accurate and sensitive determination of lead in red pepper samples and assessment of green profile

This study describes the determination of lead at trace levels by slotted quartz tube flame atomic absorption spectrophotometry (SQT-FAAS) after preconcentration by the help of stearic acid coated magnetic nanoparticle (SAC-MNPs) based sonication assisted dispersive solid phase extraction (SA-DSPE). SAC-MNPs were used due to their easy separation advantages by the application of external magnetic field. All extraction parameters were optimized by response surface methodology based experimental design. The experimented data was evaluated by the analysis of variance. Under the optimum conditions, about 31 folds enhancement in detection power was obtained over the conventional FAAS. The recovery results obtained for samples spiked at 60 and 120 ng mL−1 were 106.6 and 102.6%, respectively, validating the method as accurate and applicable to the red pepper matrix. The percent relative standard deviations of the results were under 5.0% even at low concentrations that established high precision for replicate extractions and instrumental readings.

A novel analytical method for the determination of cadmium in sorrel and rocket plants at ultratrace levels: Magnetic chitosan hydrogels based solid phase microextraction-slotted quartz tube-flame atomic absorption spectrophotometry

A novel preconcentration method based on the magnetic chitosan hydrogels (MCH) was developed for trace level determination of cadmium in sorrel (Rumex acetosella) and rocket (Eruca sativa) as edible plants. Magnetic Fe3O4@chitosan composites were synthesized, characterized and used to obtain lower detection limits for cadmium by slotted quartz tube (SQT) - atomic absorption spectrophotometry (FAAS). The Box Behnken multivariate design was used to optimize the experimental variables. Under the optimum conditions, developed method provided 97.5 fold enhancements in detection power when compared to conventional FAAS. Proposed method also provided low detection and quantification limits (0.20 and 0.68 ng/mL, respectively), high precision with %RSD of 5.3 and high accuracy with recoveries ranged from 96.0–110.4% for Rumex acetosella and Eruca sativa matrices, respectively. The results demonstrated that magnetic chitosan hydrogels could be promising materials to be used as sorbent material in solid phase microextraction yielding simple, cost-effective and environmentally friendly preconcentration process.

Trace determination of cobalt in biological fluids based on preconcentration with a new competitive ligand using dispersive liquid-liquid microextraction combined with slotted quartz tube–flame atomic absorption spectrophotometry

A new competitive ligand has been synthesized for the preconcentration to obtain lower detection limits by using dispersive liquid-liquid microextraction combined with slotted quartz tube-flame atomic absorption spectrophotometry (DLLME-SQT-FAAS). The proposed method is simple, eco-friendly and has high sensitivity. The preconcentration procedure was optimized on the basis of various parameters affecting the complex formation and extraction efficiency such as pH and volume of buffer solution, volume of ligand solution, mixing period, volume and type of extraction solvent, volume and type of dispersive solvent, and salt effect. Instrumental parameters were also optimized to get higher sensitivity. Under the optimum conditions, the calibration graph was linear in the range of 10–250 ng mL−1and the resulted limits of detection and quantification (LOD and LOQ) for combined method were 4.7 and 15.7 ng mL−1, respectively. The detection power was improved 48-fold using DLLME-SQT-FAAS method compared to conventional FAAS. The precision of the method was found to be high with a relative standard deviation of 2.5%. The accuracy of method was evaluated by recovery experiments using matrix matching study on spiked urine and blood samples. The recoveries for urine and blood samples ranged from 99.8 to 108.9% and 102.5 to 110.0%, respectively.