Slotted Quartz Tube Research Articles

Combination of High Performance Liquid Chromatography and Flame Atomic Absorption Spectrophotometry Using a Novel Nebulizer Interface Supported T Shaped Slotted Quartz Tube for the Determination of Vitamin B12

Combination of High Performance Liquid Chromatography and Flame Atomic Absorption Spectrophotometry Using a Novel Nebulizer Interface Supported T Shaped Slotted Quartz Tube for the Determination of Vitamin B12

Simultaneous Complexation and Microextraction Using Verbenone Hydrazone as the Ligand with Slotted Quartz Tube-Flame Atomic Absorption Spectrometry (FAAS) for the Sensitive Determination of Copper

A simple and rapid analytical method was developed for the determination of copper in air conditioner effluent at trace levels by slotted quartz tube – flame atomic absorption spectrometry (FAAS). Verbenone hydrazone was used as a new ligand for the complexation process. Dispersive assisted simultaneous complexation and extraction were used for preconcentration. For this purpose, verbenone hydrazone used as complexing agent was dissolved in the extraction solvent (chloroform) and mixed with the dispersive solvent (ethanol). The mixture was injected into the tube containing the standard/sample solution and buffer for the simultaneous extraction and complexation of the analyte. Optimization studies included the type and volume of buffer solution, the type and volume of dispersive solvent, the volume of the ligand solution, the mixing type and period, and the volume of nitric acid. After the optimization studies, a 2.2, 19.7 and 50-fold enhancement in detection power were obtained for slotted quartz tube – flame atomic absorption spectrometry, dispersive assisted simultaneous complexation and extraction – flame atomic absorption spectrometry, and dispersive assisted simultaneous complexation and extraction-slotted quartz tube – flame atomic absorption spectrometry, respectively. The limit of detection, limit of quantitation, and relative standard deviation of the dispersive assisted simultaneous complexation and extraction-slotted quartz tube-flame atomic absorption spectrometry system were 6.0 µg/L, 20.0 µg/L and 10.4% for the lowest concentration, respectively. The developed system was applied to air conditioner effluent samples with high recoveries between 96.8 and 122.6%.

Determination of copper in traditional coffee pot water samples by flame atomic absorption spectrometry and matrix matching calibration strategy after switchable solvent based liquid-phase microextraction.

Traditional copper coffee pots are widely used in these modern times and daily consumption of coffee brewed in overused/old pots increases the risk of copper ingestion. This study employed a green switchable solvent-based liquid-phase microextraction (SS-LPME) method to isolate and preconcentrate copper from water boiled in coffee pots. Copper was determined by a flame atomic absorption spectrometry (FAAS) system coupled with a slotted quartz tube (SQT). 1,5-Diphenylcarbazone was added to aqueous samples to form a complex with copper before the extraction step. Box-Behnken experimental design was applied to select optimum conditions of the extraction method that were used to validate the analytical method. The limits of quantification and detection of the optimized SS-LPME-SQT-FAAS method were determined as 9.1 and 2.7μg/L, respectively. Water samples boiled in traditional coffee pots were spiked at different concentrations and analyzed to ascertain the method's accuracy and applicability to real samples. Satisfactory recovery results obtained in the range of 92-107% established good accuracy, and percent relative standard deviations lower than 8.0% also proved high precision.

Separation/Preconcentration and Determination of Lead(II) in Drinking, Spring and Lake Water Samples

Pb(II) ions were separated/preconcentrated and detected by a two-step preconcentration method (Amberlite CG-120 resin and slotted quartz tube (SQT) flame atomic absorption). The first preconcentration step was the adsorption of Pb(II) on Amberlite CG-120 resin in the drinking, spring and lake water samples before detection and then its elution using 5 mL of 3 M nitric acid. The second preconcentration step was conducted using SQT device with flame atomic absorption detection. Using a two-step preconcentration method, enrichment factor of 560 was found and detection and quantitation limits were 0.23 and 0.8 µg/L, respectively. The accuracy of the method was tested by analysis of standard reference material (Environmental Matrix Reference Material, Lake Water, TMDA-70.2) at a 95% confidence level.

Simple and Green Vortex-Assisted Switchable Solvent Liquid Phase Microextraction for the Determination of Indium in Soil with Matrix Matching and Slotted Quartz Tube (SQT) – Flame Atomic Absorption Spectrometry (FAAS)

A novel preconcentration methodology to enhance the sensitivity of a flame atomic absorption spectrometer for indium determination was investigated in this study. The proposed methodology is based on the application of switchable solvent based liquid-phase microextraction combined with a slotted quartz tube. The isolation of indium was performed using N, N-dimethylbenzylamine as the extraction solvent after complexation with (E)-2,4-dibromo-6-(((3-hydroxyphenyl)imino)methyl)phenol. The detection power was enhanced by approximately 169-fold using the developed method with respect to the conventional flame atomic absorption spectrometry system. The quantification and detection limit values were 28.3 and 8.4 ng mL−1, respectively. The assessment of several interfering ions on the analyte was performed, and spike experiments were used to validate the method’s accuracy. Interferences were observed for a ratio of 1:10 analyte:interferent with a value of 27%. The recovery results obtained using matrix matching strategy indicated the applicability of the developed method for soil matrices.

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.

Nano-sized magnetic Ni particles based dispersive solid-phase extraction of trace Cd before the determination by flame atomic absorption spectrometry with slotted quartz tube: a new, accurate, and sensitive quantification method.

In this study, a new analytical strategy was developed to determine trace cadmium in aqueous samples with high sensitivity and accuracy. A combination of magnetic nickel nanoparticles (Ni-MNPs) based dispersive solid-phase extraction (DSPE) and flame atomic absorption spectrometry fitted with a slotted quartz tube (SQT-FAAS) lowered the detection limit of cadmium. The magnetic Ni nanoparticles were synthesized, characterized, and thoroughly optimized in a stepwise approach. The quartz tube was custom cut in the laboratory to suit the specifics of the flame burner. Using the optimized conditions, a limit of detection value of 0.58 μg/L and limit of quantification value of 1.93 μg/L were obtained. To demonstrate accuracy and applicability of the developed method, well water samples were analyzed for their Cd content, and matrix effect on the extraction yield was investigated. The percent recovery results calculated ranged from 93.8 to 108.2%, with corresponding standard deviation values ranging from 1.7 to 7.7. These results established the developed method as sensitive, accurate, and precise for determination of cadmium at trace levels.

Determination of Iron in Licorice Samples by Slotted Quartz Tube Flame Atomic Absorption Spectrometry (FAAS) with Matrix Matching Calibration Strategy after Complexation with Schiff Base Ligand-Based Dispersive Liquid–Liquid Microextraction

In this study, a slotted quartz tube flame atomic absorption spectrometry (FAAS) system has been developed for the determination of iron after dispersive liquid–liquid microextraction. The iron coordinate complex was formed by using a ligand synthesized from the reaction of o-phenylenediamine and 5-bromosalicylaldehyde. Using the optimum conditions, the relative standard deviation was found to be 1.7% calculated from the lowest concentration of calibration plot, and the limits of detection and quantification were found to be 5.3 and 17.4 µg L−1, respectively. Other figures of merit of the developed method were satisfactory and an approximate 48-fold enhancement in detection power was recorded compared to the conventional FAAS system. The developed method was applied to licorice samples to evaluate the accuracy and applicability to real samples. The recovery values were in the range from 88% to 106% with low standard deviations.

A Simultaneous Dispersive Liquid–Liquid Microextraction-complexation Method to Determine Trace Cobalt in Chamomile Tea Extract Prior to Slotted Quartz Tube Flame Atomic Absorption Spectrometry

A novel and effective analytical method was developed for the determination of trace cobalt by slotted quartz tube flame atomic absorption spectrometry (SQT-FAAS) after simultaneous dispersive liquid-liquid microextraction (S-DLLME) based on contemporaneous complexation and extraction. Approximately 48 times enhancement in detection power was recorded based on the comparison of detection limits of the developed system (4.7 ng/mL) with the detection power of the conventional FAAS. Percent relative standard deviation for the lowest concentration was calculated as 3.8%. Spiked recovery experiments on chamomile tea extract samples were carried out to determine applicability of the developed method to real sample matrix. Percent recovery results for two different concentrations were approximately 100%, with standard deviation values below 10%.

A Simple and Green Vortex-Assisted Switchable Solvent-Based Microextraction Method by Using Schiff Base Ligand Complexation for Iron Determination in Mineral Spring Water Samples Prior to Slotted Quartz Tube Flame Atomic Absorption Spectrophotometry

In this study, a vortex-assisted switchable solvent microextraction (VA-SSME) method was developed for the determination of iron by slotted quartz tube flame atomic absorption spectrometry (SQT-FAAS). A ligand synthesized from the reaction of ortho-phenylenediamine and 5-bromosalicylaldehyde was used to form a coordinate complex of iron. All experimental variables such as switchable solvent amount, sodium hydroxide concentration, sodium hydroxide amount, and diluent amount were optimized to increase extraction efficiency for the iron complex. Optimum conditions were applied to aqueous standard solutions in the range of 20–750 ng/mL, and the percent relative standard deviation (%RSD) was less than 2.0%. The limit of detection (LOD) and limit of quantification (LOQ) were determined as 4.8 and 16.2 ng/mL, respectively. The optimized method recorded approximately 53 times enhancement according to the conventional FAAS system. The proposed method was applied to mineral spring water samples, and satisfactory percent recovery results (100–105%) were obtained for iron, indicating good applicability in addition to high accuracy.

Development of sensitive analytical methods for the determination of thallium at trace levels by slotted quartz tube flame atomic absorption spectrometry

A simple, sensitive and economical technique is needed for the determination of thallium and this study demonstrates the different analytical strategies were developed using atomic absorption spectrometry (AAS). In order to improve the sensitivity of flame atomic absorption spectrometry (FAAS), a basic slotted quartz tube (SQT) was used for the thallium determination. In the first strategy, mixing propanol (100 μL) and Tl standard solution (500 μL) under the optimum conditions, namely solvent assisted SQT-FAAS, provided 4.49 folds enhancement in detection power with the help of better nebulization efficiency and/or atomization of analytes. Furthermore, SQT was used as an atom trap, AT as the second strategy. In this method, analyte atoms were trapped for 5.0 min on the SQT inner surface under the lean flame. In addition, a novel analytical method was developed using an inner surface coated SQT with metals with low volatility (palladium, tungsten, molybdenum, zirconium, tantalum, osmium and titanium). Under the all optimum conditions, limit of detection values were found to be 38 ng mL−1 and 3.5 ng mL−1 for SQT-AT-FAAS and Os-Coated-SQT-AT-FAAS methods, respectively. 319 folds improvement in detection power was obtained by Os-Coated-SQT-AT-FAAS method with respect to conventional FAAS.

Chitosan magnetic hydrogel based ligandless magnetic solid phase extraction for the accurate and sensitive determination of thallium by slotted-quartz tube flame atomic absorption spectrophotometry with matrix matching calibration strategy

In this study, a promising method was developed for the determination of thallium at trace levels by applying chitosan based magnetic solid phase extraction using slotted quartz tube atomic absorption spectrometry. Chitosan based magnetic hydrogels (CMH) were synthesized and used as solid phase extraction sorbents. The variable parameters required for the extraction method such as hydrogel amount, adsorption period and eluent volume were optimized, and under the optimized conditions, limits of detection and quantification values were recorded as 12 and 39 ng/mL, respectively. Real sample applications were performed to test the accuracy of the proposed method. For this purpose, recovery studies were carried out in two different spiking concentrations of thallium in lake water, well water and wastewater samples using the developed extraction/preconcentration method (chitosan magnetic hydrogel based ligandless magnetic solid phase extraction, CMH-LMSPE). The obtained percent recovery values of 87.2–113.2% confirmed the applicability of the method with high accuracy and precision.

Combination of Slotted Quartz Tube Flame Atomic Absorption Spectrometry and Dispersive Liquid–Liquid Microextraction for the Trace Determination of Silver in Electroplating Rinse Bath

Although flame atomic absorption spectrometry (FAAS) is hindered by its low sensitivity for most elements, it remains a widely used analytical technique in most laboratories. This study was aimed at mitigating the low sensitivity of an FAAS system by using dispersive liquid-liquid microextraction (DLLME) to enrich silver from aqueous solution, and enhance absorbance signals with the help of a slotted quartz tube (SQT). Three major optimization steps were carried for parameters of complexation (silver-dithizone), DLLME method and SQT apparatus. The optimum parameters/variables obtained were applied to aqueous standard solutions, and the developed calibration plots were used to validate the different systems studied. The optimized method (DLLME-SQT-FAAS) recorded an enhancement factor of 98, which correlates to detection and quantification limits of 0.60 µg/L and 2.0 µg/L, respectively. The optimized method was applied to an electroplating rinse solution, and close to 100% recovery results were obtained for different spiked concentrations. These results establish that the developed method can be applied to complex samples for accurate quantification of silver.

Determination of Copper in Quince Samples with a Matrix Matching Strategy Using Vortex Assisted Deep Eutectic Solvent-Based Emulsification Liquid Phase Microextraction – Slotted Quartz Tube – Flame Atomic Absorption Spectrometry

A vortex assisted deep eutectic solvent-based emulsification liquid-phase microextraction method was developed for the extraction and preconcentration of copper at trace levels followed by determination with slotted quartz tube – flame atomic absorption spectrometry. Various experimental factors were systematically optimized by performing single variant experiments to enhance detection power. Under the optimized conditions, the calibration plot showed linearity in the concentration range from 2.5 to 100 μg L−1. The developed method offered limits of detection and quantification equal to 0.5 and 1.8 μg L−1, respectively. The relative standard deviation (n = 6) for the lowest concentration of the calibration plot was lower than 6.0% which demonstrates good precision. The enhancement in the detection power was 160-fold by the developed vortex assisted deep eutectic solvent-based emulsification liquid phase microextraction – slotted quartz tube – flame atomic absorption spectrometry method. The validity and accuracy of the proposed method were confirmed through recovery experiments on quince samples. Acceptable percent recoveries in the range from 93.6 to 117.6% were obtained.

Sensitive determination of nickel at trace levels in surface water samples by slotted quartz tube flame atomic absorption spectrometry after switchable solvent liquid-phase microextraction.

In this study, switchable solvent (SS) for liquid-phase microextraction (LPME) was used as a tool to preconcentrate nickel from aqueous samples for determination by flame atomic absorption spectrometry. The SS-LPME method was optimized thoroughly to boost the absorbance signal of nickel for trace level determination. Parameters optimized included switchable solvent volume, sodium hydroxide concentration, sodium hydroxide volume, and eluent volume. The SS-LPME method enhanced the detection power by about 32-folds, and a slotted quartz tube (SQT) was used to obtain 2.6-folds increase in detection power. The combination of LPME and SQT-FAAS produced 104-folds enhancement, correlating to a limit of detection value of 1.8μg/L. Low relative standard deviations calculated for the lowest calibration concentration indicated good repeatability for replicate measurements. Accuracy of the optimized method and its applicability to real samples was tested on two river samples. The results (85-103%) obtained from the spike recovery experiments were satisfactory.

Reverse phase dispersive liquid–liquid microextraction coupled to slotted quartz tube flame atomic absorption spectrometry as a new analytical strategy for trace determination of cadmium in fish and olive oil samples

In the present study, trace level of cadmium was determined by a new, sensitive and simple analytical method called as reverse phase dispersive liquid–liquid microextraction (RP-DLLME) combined to slotted quartz tube flame atomic absorption spectrometry (SQT-FAAS) system. Microextraction parameters such as type and volume of disperser solvent, volume of extraction solvent, heating effect, initial sample volume, final volume, centrifugation period and type/period of mixing were optimized. FAAS and SQT-FAAS systems were also examined to get high signal to noise ratio. After optimizing all significant parameters, the limit of detection (LOD) and limit of quantification (LOQ) of the developed analytical strategy were calculated as 0.74 and 2.48 μg/kg, respectively. In order to determine the applicability and accuracy of the RP-DLLME-SQT-FAAS method, recovery studies were performed in fish oil syrup. Matrix matching calibration strategy was used to eliminate heavy matrix effects on analytical signals, and percent recovery results were found between 95.6 and 105.7 %.

A sensitive and accurate analytical method for the determination of cadmium in food samples: Molybdenum coated T-shape slotted quartz tube flame atomic absorption spectrophotometry

In this study, a molybdenum coated T-shaped slotted quartz tube atom trap flame atomic absorption spectrophotometry method (Mo coated-T-SQT-AT-FAAS) was developed for the determination of cadmium with on-line preconcentration. Inner surface of T-SQT was coated with molybdenum to enhance the trapping efficiency. Hydrogen gas was used instead of organic solvents to release trapped atoms. Limit of detection and quantification were found to be 0.057 and 0.082 µg/L, respectively. The developed method has a linear working range between 0.10 and 1.0 µg/L with a low %RSD value (<3.7). About 1202 times enhancement in detection power was recorded over the conventional FAAS system. Recovery experiments were used to determine the applicability of the method developed to real samples (linden, milk powder and mint) and significant results (94.4–100.7%) were obtained for the samples spiked at 0.30, 0.50 and 1.0 µg/L. The method was also applied to Tomato Leaves 1573a SRM to check the accuracy.

Determination of Trace Amounts of Gold in Electroplating Rinsing Bath by Slotted Quartz Tube Flame Atomic Absorption Spectrometry with Matrix Matching Calibration Strategy after Preconcentration with Vortex Assisted Dispersive Liquid–Liquid Microextraction

With the aim of mitigating the low sensitivity of the conventional flame atomic absorption spectrometer (FAAS) for gold determination, a dispersive liquid–liquid microextraction (DLLME) method was used to preconcentrate gold from the sample solution and a slotted quartz tube (SQT) was attached to the FAAS burner head to boost the residence time of the atoms in the flame. Three main optimization studies were performed to enhance the absorbance signal of gold by the FAAS system. The SQT-FAAS system was optimized based on the fuel and sample flow rates and the position of SQT on the burner head. Parameters including the pH and volume of buffer solution, volume of ligand solution, and mixing period were optimized for the efficient complexation of gold with diethyldithiocarbamate. The DLLME method was optimized based on the type and volume of dispersive and extraction solvents, type of ionic salt and mass of ionic salt. With the optimized values obtained, 1.7 and 5.6 µg/L were determined to be the method limit of detection (LOD) and limit of quantification (LOQ), respectively. The method applicability and accuracy in quantifying gold in a real sample matrix were determined by the use of spike recovery tests of electroplating rinse bath solution. Close to 100% recovery results were obtained using a matrix matching calibration method.

A sieve-conducted two-syringe-based pressurized liquid-phase microextraction for the determination of indium by slotted quartz tube-flame atomic absorption spectrometry.

In this study, a new liquid-phase microextraction method termed sieve-conducted two-syringe-based pressurized liquid-phase microextraction (SCTS-PLPME) was developed as a preconcentration tool for indium. Here, two syringes were connected to each other by an apparatus to produce an environment subject to pressure. The pressure created between the two syringes by simultaneous movements of the syringe plungers (to and fro) generated an efficient dispersion and this eliminated the need for dispersive solvents. Determination of indium after preconcentration was carried out with a slotted quartz tube attached flame atomic absorption spectrometer (SQT-FAAS). The detection limit (LOD) and quantification limit (LOQ) of the developed method were calculated as 19.2 and 72.2μgL-1, respectively. The reliability and accuracy of the developed method was tested by performing recovery studies on lake water spiked at different concentrations and the obtained percent recoveries were between 101.2 and 106.9%.

Ultra-trace cadmium determination in eucalyptus and rosemary tea samples using a novel method: deep eutectic solvent based magnetic nanofluid liquid phase microextraction-slotted quartz tube-flame atomic absorption spectrometry

A deep eutectic solvent-based magnetic nanofluid liquid phase microextraction method was developed for the preconcentration of cadmium prior to its determination using the slotted quartz tube flame atomic absorption spectrophotometry system.