Headspace Liquid-phase Microextraction Research Articles

A new miniaturized microextraction HS-LPME-OIP procedure for ammonium determination based on Nessler's method

A recently proposed combination of headspace liquid-phase microextraction with an optical immersion probe (HS-LPME-OIP) was adapted for the spectrophotometric determination of ammonium. The developed method is based on the conversion of ammonium ions to ammonia in a 0.15 M sodium hydroxide solution, followed by the absorption of ammonia by 200 µL of Nessler's reagent solution preliminary diluted with distilled water (1:16.7). The extracting phase, in which OIP was immersed, was placed into vial fixed in the headspace above the sample solution in a hermetically sealed vessel. The analytical signal was monitored for 30 min at 400 nm. The duration of the analysis can be flexibly adjusted and, if necessary, reduced to 5 min. The level of permissible concentrations of some interfering substances, including calcium, magnesium, iron and some organic compounds, was significantly reduced. The LOD was equal to 0.20 mg L−1, and the linear calibration range was from 0.70 to 15 mg L−1. The RSD ranged from 2.5 to 5.2%. The developed method was successfully applied to the analysis of natural waters, fertilizers and CRM samples.Graphical abstract

In situ formation of AuNPs in liquid bead-headspace microextraction of arsine for colorimetric sensing of trace As(III)

A simple yet sensitive colorimetric method based on in situ formation of AuNPs in liquid bead-headspace microextraction of arsine has been developed for ultrasensitive sensing of trace As(III). Taking advantage of our self-designed sensing device, the strong reductant AsH3 generated from the hydride generation of As(III) passed through a platform and reacted with a liquid bead (60 μL, containing HAuCl4, KI, PVP and PVA) for the formation of AuNPs inside. Due to the synergistic reduction of iodine ions and the stabilization of polymers, AuNPs could be formed quickly, and the color of liquid-bead changed from yellow to red, which deepened in proportion to the As(III) concentration. Under the optimal experimental conditions, a linear range of 10–500 µg/L with a correlation coefficient up to 0.999 was achieved. Trace As(III) as low as 5 μg/L could produce visible color change. Combining the advantages of hydride generation, headspace liquid-phase microextraction and AuNPs-based colorimetric assay, including efficient matrix separation and analyte enrichment, rapid mass transfer, and visual observation of color change, the proposed sensor features high sensitivity, great selectivity, strong stability and simplicity, enabling successful applications for As(III) detection in water samples.

Application of gas flow headspace liquid phase micro extraction coupled with gas chromatography-mass spectrometry for determination of 4-methylimidazole in food samples employing experimental design optimization.

Background4-Methylimidazole (4-MeI) or 4-methyl-1H-imidazole, a slightly yellowish solid with molecular formula C4H6N2, is a heterocyclic compound which supposedly does not exist as a natural product and is formed when carbohydrates are heating with ammonium compounds. This compound is used in pharmaceuticals, agriculture and photography chemicals, dyes and pigments, and rubber manufacturing. In the present study, a simple and efficient sample preparation method designated gas flow headspace liquid phase microextraction (GF-HS-SDME) was employed for the extraction and preconcentration of 4-methylimidazole (4-MeI) from food and beverage samples, before its determination by gas chromatography-mass spectrometry.ResultTo investigate the optimal conditions for the extraction process in GF-HS-SDME method, factors affecting extraction, including selection of extraction solvent, vial volume, extraction solvent ratio, position of extracting solvent, drop volume, sample volume, stirring speed, temperature, extraction time, sample pH, ionic strength of the sample solution and gas flow rate were optimized by utilizing both one-variable-at-a-time method and Plackett–Burman design. The investigation of protocol was carried out by using a standard solution containing 100.0 μg L−1 of 4-MeI in deionized water.ConclusionIn this study, a simple and green analytical method based on GF-HS-SDME was proposed for the extraction and preconcentration of 4-MeI from foodstuffs, followed by GC–MS determination. The main advantage of this method is its high preconcentration factor and fastness due to the application of an inert gas stream during microextraction.Supplementary InformationThe online version contains supplementary material available at 10.1186/s13065-022-00823-z.

Back Cover: Single bubble in‐tube microextraction coupled with capillary electrophoresis

DOI: 10.1002/elps.202100216 The cover picture shows three modes of headspace liquid phase microextraction (HS-LPME) in-line coupled with CE. Headspace single drop microextraction (HS-SDME)-CE: When a single drop of the acceptor phase (blue) is formed at the inlet of a separation capillary filled with a run buffer (pale pink), the analytes evaporated from the sample donor solution (green) into the HS are extracted into the drop leaving less- or non-volatile matrix components in the sample. After extraction, a portion of the drop containing enriched analytes is injected into the capillary for CE analysis. Due to the large volume ratio between the sample donor solution and the acceptor drop, and the large surface-to-volume ratio of the drop, the sample enrichment factors obtained with SDME are quite high for a given extraction time, compared with other conventional LPME techniques. However, it is critical to maintain the drop stably attached to the capillary during extraction and thus it is rather difficult to carry out SDME for a long time especially under harsh conditions such as elevated temperature. Headspace in-tube microextraction (HS-ITME)-CE: Using a liquid plug in the capillary inlet as an acceptor phase instead of a hanging drop, the shortcomings of the hanging drop can be resolved. In HS-ITME-CE, the capillary inlet containing the acceptor plug is simply placed in the HS above a sample solution. Since the acceptor phase is well protected by the capillary, a long extraction at a temperature as high as 90°C can be performed with ease. Furthermore, since the enriched acceptor plug is already inside the capillary, the whole extract can be utilized for the subsequent CE analysis without additional injection step. Single bubble in-tube microextraction (SB-ITME)-CE: For a short extraction time, the extraction efficiency of HS-SDME or HS-ITME was not maximized because it takes some time for the analytes to fill the HS and reach saturated concentrations, especially for compounds of low volatility. By using a single bubble as a micro-HS formed at the inlet of a separation capillary immersed in the sample donor solution, the HS extraction can be expedited without waiting for the HS equilibration. Since the surface-to-volume ratio of the submicroliter bubble is much higher than that of a conventional HS of a few milliliters or more, the analyte concentrations in the bubble can be replenished much more rapidly for short extraction times. SB-ITME demonstrated higher sample enrichments than HS-ITME for a short HS extraction of chlorophenols in water.

Online determination of sulfide using an optical immersion probe combined with headspace liquid-phase microextraction.

A new design for headspace liquid phase microextraction in combination with an optical immersion probe (HS-LPME-OIP) was proposed and successfully tested for the determination of sulfide in wine and water samples. The developed method is based on the release of hydrogen sulfide from the aqueous phase after the addition of orthophosphoric acid and its extraction with an aqueous solution of 5,5′-dithiobis-(2-nitrobenzoic) acid (DTNB). The analytical signal was recorded using an optical probe immersed in a vial containing 200 μL of 0.1 mM DTNB solution. Using the optical immersion probe in combination with HS-LPME allowed to register the analytical signal online and significantly improve the reproducibility of sulfide determination compared to known microextraction approaches. In the proposed approach, the problems with drop stability, limitations in mixing rate or extraction time, too small volume of the acceptor phase and stability of the holding the acceptor phase in the hole of the optical probe were also satisfactorily solved. The calibration graph was linear in the range of 16–256 μg L−1 with a correlation coefficient of 0.9992. The limit of detection was 6 μg L−1.

A new approach for sulfite determination by headspace liquid-phase microextraction with an optical probe.

A new approach of headspace liquid-phase microextraction with an optical probe (HS-LPME-OP), which solves the problem of the extraction phase retention in the hole of the optical probe and provides the possibility of simpler, more precise and reliable online processing of the analytical signal, was used for sulfite determination. A 1 × 10-4 M 5,5'-dithiobis-(2-nitrobenzoic) acid (DTNB) solution was used as an acceptor phase. It was placed in a plastic vial fixed in the headspace above the analyte solution. An optical probe immersed in the acceptor phase was used to monitor the analytical signal. Sulfite determination is based on the release of sulfur dioxide from the sample after the addition of ortho-phosphoric acid, followed by its extraction with an aqueous solution of DTNB at pH 7.0. The absorbance was measured at 412 nm. The calibration graph was linear in the range from 32 to 320 μg L-1 with a detection limit of 14 μg L-1. The developed method is sensitive, highly selective and reproducible. It was successfully applied for the sulfite determination in juice, alcoholic beverages and jam.

In-vessel headspace liquid-phase microextraction

A new mode of headspace liquid-phase microextraction termed in-vessel headspace liquid-phase microextraction (IV-HS-LPME) has been developed. A plastic vessel was used as a holder for an extraction phase. Problems with drop stability, limitations in the stirring speed, and too little volume of the acceptor phase have been completely eliminated. The proposed approach is fully compatible with ordinary instruments and microcuvettes used in spectrophotometry. The potential of the method was evaluated by determining the iodide concentration in various samples. Iodide in the donor phase was converted to volatile I2 by oxidation with 1 mmol L−1 K2Cr2O7. The reaction mixture was agitated on a magnetic stirrer for 30 min at a stirring speed of 1200 rpm. A 1% (w/v) aqueous solution of KI was used as the acceptor phase. The absorbance of the I3− ion formed in the acceptor phase was measured in a 50 μL microcuvette at 350 nm. For the case of extraction from 10 mL donor solution into 50 μL of acceptor phase, the calibration graph is linear in the range of 20–400 μg L−1 (as I−) with a detection limit of 6 μg L−1. The developed method has a high precision comparable to conventional spectrophotometric methods (0.6–1.5%). The extraction efficiency obtained in the optimal conditions was 10.5%. The distribution constants for equilibria between the donor solution and the headspace and between the headspace and the acceptor solution are 0.8 ± 0.1 and 16 ± 2, respectively. The developed method was successfully applied to determine the iodine content in natural waters, medicines and algae.

In-Vessel Headspace Liquid Phase Microextraction Coupled to Spectrophotometry for Iodate Determination

A new, highly sensitive and selective method for the spectrophotometric determination of iodate is developed based on the in-vessel mode of headspace liquid phase microextraction (IV-HS-LPME). The approach involves converting iodate to vapor iodine with excess of iodide and extracting it into a 50 μL of 1 % potassium iodide, which exposed to the headspace in a specially designed vessel. The extraction proceeds from 8 mL of aqueous solution containing 0.24 mmol L-1 of iodide and 0.5 mol L-1 of Na2SO4 after injection of 2 mL of 25 % H2SO4. The complete equilibrium is established after the aqueous solution stirred at 1200 rpm for 20 minutes. After that, the triiodide complex formed in the acceptor phase is withdrawn with a microsyringe and transferred to a 50 μL quartz micro cell with a 10 mm path length, where the absorbance is measured at 288 or 350 nm. The calibration graph is linear (r2 = 0.9998) in the range of 4 to 180 μg L-1 (as IO3-) with a detection limit of 1.5 μg L-1. The developed method has a high precision of 0.5 – 1.4 %. It was successfully applied to the determination of iodate in table salt, sea, and mineral water samples.

Detection of Polycyclic Aromatic Hydrocarbons in Water Samples by Annular Platform-Supported Ionic Liquid-Based Headspace Liquid-Phase Microextraction.

In this paper, a new method of annular platform-supported headspace liquid-phase microextraction (LPME) was designed using ionic liquid as an extraction solvent, wherein extraction stability and efficiency were improved by adding an annular platform inside the extraction bottle. The ionic liquid 1-silicyl-3-benzylimidazolehexafluorophosphate was first synthesized and proved to be an excellent extraction solvent. Coupled with liquid chromatography, the proposed method was employed to analysis of polycyclic aromatic hydrocarbons (PAHs) in water and optimized in aspects of extraction temperature, extraction solvent volume, extraction time, pH, stirring rate, and salt effect of solution. The results indicated that this method showed good linearity (R2 > 0.995) within 0.5 µg·L−1 to 1000 µg·L−1 for PAHs. The method was more suitable for extraction of volatile PAHs, with recoveries from 65.0% to 102% and quantification limits from 0.01 to 0.05 µg·L−1. It has been successfully applied for detection of PAHs in seawater samples.

A paper-based analytical device for the determination of hydrogen sulfide in fuel oils based on headspace liquid-phase microextraction and cyclic voltammetry

An easily performed miniaturized, cheap, selective and sensitive procedure for the determination of H2S in fuel oil samples based on a headspace liquid-phase microextraction followed by a cyclic voltammetry detection using a paper-based analytical device (PAD) was developed. A modified wax dipping method was applied to fabricate the PAD. The PAD included hydrophobic zones of sample and supporting electrolyte connecting by hydrophilic channel. The zones of sample and supporting electrolyte were connected with nickel working, platinum auxiliary and Ag/AgCl reference electrodes. The analytical procedure included separation of H2S from fuel oil sample based on the headspace liquid-phase microextraction in alkaline solution. Then, sulfide ions solution obtained and supporting electrolyte were dropped on the zones followed by analyte detection at + 0.45 V. Under the optimized conditions, H2S concentration in the range from 2 to 20 mg kg−1 had a good linear relation with the peak current. The limit of detection (3σ) was 0.6 mg kg−1. The procedure was successfully applied to the analysis of fuel oil samples.

Determination of Pyridine as a Decomposition Product in Ceftazidime and Mouthwash Solution

In this study, a dynamic headspace liquid-phase microextraction method is reported for the extraction and preconcentration of pyridine as a decomposition product in some pharmaceuticals before its determination by gas chromatography–flame ionization detection. In the practical procedure, 5 µL of dimethyl sulfoxide (extraction/collection solvent) containing 1-pentanol (internal standard) is placed into a liner-shaped extraction vessel. The vessel is passed through the septum of a vial containing the sample solution. Then it is placed into a water bath thermostated at 70 °C. After a predetermined time, 1 µL of the extraction/collection solvent is removed and injected into the separation system. The factors influencing the extraction efficiency including extraction/collection solvent kind and its volume, ionic strength, extraction time, extraction temperature, and pH were investigated and optimized. Under optimum extraction conditions, the method showed a wide linear range between 0.012 and 500 mg L−1. Enrichment factor and extraction recovery were obtained as 314 and 94%, respectively. Limit of detection was calculated as 0.004 mg L−1 in solution and 0.08 mg kg−1 in solid. Relative standard deviation for the extraction of 0.05 mg L−1 of the analyte was obtained as 4 and 6% for intra-day (n = 6) and inter–day (n = 4) precisions, respectively. Finally, the target analyte was determined in ceftazidime and mouthwash solution by the proposed method.

Highly porous nanostructured copper foam fiber impregnated with an organic solvent for headspace liquid-phase microextraction

A new headspace liquid-phase microextraction technique based on using a copper foam nanostructure substrate followed by gas chromatography-flame ionization detection was developed for the determination of volatile organic compounds in water and wastewater samples. The copper foam with highly porous nanostructured walls was fabricated on the surface of a copper wire by a rapid and facile electrochemical process and used as the extractant solvent holder. Propyl benzoate was immobilized in the pores of the copper foam coating and used for the microextraction of benzene, toluene, ethylbenzene and xylenes. The experimental parameters such as the type of organic solvent, desorption temperature, desorption time, salt concentration, sample temperature, equilibrium time and extraction time, were investigated and optimized. Under the optimum conditions, the method detection limit was between 0.06 and 0.25μgL−1. The relative standard deviation of the method for the analytes at 4–8μgL−1 concentration level ranged from 7.9 to 11%. The fiber-to-fiber reproducibility for three fibers prepared under the same condition was 9.3–12%. The enrichment factor was in the range of 615–744. Different water samples were analyzed for the evaluation of the method in real sample analysis. Relative recoveries for spiked tap, river and wastewater samples were in the range of 85–94%. Finally, the extraction efficiency of the method was compared with those of headspace single drop microextraction and headspace SPME with the commercial fibers.

Extraction and preconcentration of residual solvents in pharmaceuticals using dynamic headspace-liquid phase microextraction and their determination by gas chromatography-flame ionization detection.

The present study describes a microextraction and determination method for analyzing residual solvents in pharmaceutical products using dynamic headspace-liquid phase microextraction technique followed by gas chromatography-flame ionization detection. In this method dimethyl sulfoxide (μL level) placed into a GC liner-shaped extraction vessel is used as a collection/extraction solvent. Then the liner is exposed to the headspace of a vial containing the sample solution. The effect of different parameters influencing the microextraction procedure including collection/extraction solvent type and its volume, ionic strength, extraction time, extraction temperature and concentration of NaOH solution used in dissolving the studied pharmaceuticals are investigated and optimized. Under the optimum extraction conditions, the method showed wide linear ranges between 0.5 and 5000 mg L-1 . The other analytical parameters were obtained in the following ranges: enrichment factors 240-327, extraction recoveries 72-98% and limits of detection 0.1-0.8 mg L-1 in solution and 0.6-3.2 μg g-1 in solid. Relative standard deviations for the extraction of 100 mg L-1 of each analyte were obtained in the ranges of 4-7 and 5-8% for intra-day (n = 6) and inter-day (n = 4) respectively. Finally the target analytes were determined in different samples such as erythromycin, azithromycin, cefalexin, amoxicillin and co-amoxiclav by the proposed method.

Use of volatile organic solvents in headspace liquid-phase microextraction by direct cooling of the organic drop using a simple cooling capsule.

A low-cost and simple cooling-assisted headspace liquid-phase microextraction device for the extraction and determination of 2,6,6-trimethyl-1,3 cyclohexadiene-1-carboxaldehyde (safranal) in Saffron samples, using volatile organic solvents, was fabricated and evaluated. The main part of the cooling-assisted headspace liquid-phase microextraction system was a cooling capsule, with a Teflon microcup to hold the extracting organic solvent, which is able to directly cool down the extraction phase while the sample matrix is simultaneously heated. Different experimental factors such as type of organic extraction solvent, sample temperature, extraction solvent temperature, and extraction time were optimized. The optimal conditions were obtained as: extraction solvent, methanol (10 μL); extraction temperature, 60°C; extraction solvent temperature, 0°C; and extraction time, 20 min. Good linearity of the calibration curve (R(2) = 0.995) was obtained in the concentration range of 0.01-50.0 μg/mL. The limit of detection was 0.001 μg/mL. The relative standard deviation for 1.0 μg/mL of safranal was 10.7% (n = 6). The proposed cooling-assisted headspace liquid-phase microextraction device was coupled (off-line) to high-performance liquid chromatography and used for the determination of safranal in Saffron samples. Reasonable agreement was observed between the results of the cooling-assisted headspace liquid-phase microextraction high-performance liquid chromatography method and those obtained by a validated ultrasound-assisted solvent extraction procedure.

Development of a New Dynamic Headspace Liquid-Phase Microextraction Method

A new technique, namely dynamic headspace liquid-phase microextraction, has been developed for the extraction of 1,4-dioxane in cosmetic and hygiene samples followed by gas chromatography–flame ionization detection. In this method, the sample is mixed with acetone as a diluent solvent. Then, a few microliters of n-octanol are added into a home-made extraction vessel placed in the headspace of the sample. By heating, the target analyte is transferred to the headspace of the sample and then extracted into n-octanol. Under the optimized conditions, the method showed a good linearity in the range of 3.24–1000 μg kg−1 with a coefficient of determination 0.998. Figures of merit such as enrichment factor of 375, extraction recovery of 94 %, limits of detection and quantification 0.97 and 3.24 μg kg−1, respectively, and relative standard deviation 4.7 % (n = 6, C = 30 μg kg−1) of the proposed method were satisfactory for determination of the target analyte. Finally, the method was successfully applied in determination of 1,4-dioxane in various cosmetic and hygiene samples including shampoo, toothpaste, lotion, washing liquid, and dishwashing liquid.

Development of dynamic headspace-liquid phase microextraction method performed in a home-made extraction vessel for extraction and preconcentration of 1,4-dioxane from shampoo

In the present study, a new, simple, rapid, and environmentally friendly headspace-liquid phase microextraction method followed by gas chromatography–flame ionization detection has been developed for the extraction/preconcentration and determination of 1,4-dioxane from shampoo. The developed procedure is performed in a home-made extraction vessel, connected to a glass vial containing sample and extraction solvent. In this method, an aliquot weight of shampoo is mixed with a binary mixture of n-hexane and dichloromethane (50:50, v/v) as the extractant and the target analyte is extracted during a liquid–liquid extraction procedure. Then a home-made extraction vessel containing a few microliters of a collection/extraction solvent is contacted to a glass vial containing the organic phase obtained from the previous step. By heating 1,4-dioxane is vaporized and enriched in a μL volume of the collection/extraction solvent. Then an aliquot volume of the collected phase is injected into the separation system. The effect of several factors which may influence performance of the method, including kind and volume of the extraction solvents used in both steps, extraction temperature, extraction time, and salt addition were evaluated. Under the optimum extraction conditions, limits of detection and quantification for the target analyte were obtained 0.52 and 1.73 μg kg−1, respectively. Enrichment factor and extraction recovery were 333 and 89 %, respectively. The method precision was evaluated at a concentration of 25 μg kg−1 and relative standard deviation was less than 6.9 % for intra-day (n = 6) and inter-day (n = 4) precisions. Finally, the proposed method has been successfully applied in analysis of 1,4-dioxane in different shampoo samples.

Single-step microwave assisted headspace liquid-phase microextraction of trihalomethanes and haloketones in biological samples.

A single-step microwave assisted headspace liquid-phase microextraction (MA-HS-LPME) method was developed for determination of trihalomethanes (THMs) and haloketones (HKs) in biological samples. In this method, a porous membrane envelope was filled with few microliters of extraction solvent and then placed inside the microwave extraction vial. A PTFE ring was designed to support the membrane envelope over a certain height inside the vial. An optimum amount of biological sample was placed in the vial equipped with magnetic stirrer. After that nitric acid was added to the vial for digestion of biological sample. The sample was digested and the volatile THMs and HKs were extracted at headspace in the solvent containing porous membrane. After simultaneous digestion and extraction, the extract was injected to gas chromatography/mass spectrometry for analysis. Factors affecting the extraction efficiency were optimized to achieve higher extraction performance. Quantification was carried out over a concentration range of 0.3-100ngg(-1) for brominated compounds while for the chlorinated ones linear range was between 0.5-100ngg(-1). Limit of detections (LODs) were ranged from 0.051 to 0.110ngg(-1) while limit of quantification (LOQ) were in the range of 0.175-0.351ngg(-1). The relative standard deviations (RSDs) of the calibrations were ranged between 1.1 and 6.8%. The MA-HS-LPME was applied for the determination of trace level THMs and HKs in fish tissue and green alga samples.

Furanic compounds and furfural in different coffee products by headspace liquid-phase micro-extraction followed by gas chromatography–mass spectrometry: survey and effect of brewing procedures

In this study, the levels of furan, 2-methylfuran, 2,5-dimethylfuran, vinyl furan, 2-methoxymethyl-furan and furfural in different coffee products were evaluated. Simultaneous determination of these six furanic compounds was performed by a head space liquid-phase micro-extraction (HS-LPME) method. A total of 67 coffee powder samples were analysed. The effects of boiling and espresso-making procedures on the levels of furanic compounds were investigated. The results showed that different types of coffee samples contained different concentrations of furanic compounds, due to the various processing conditions such as temperature, degree of roasting and fineness of grind. Among the different coffee samples, the highest level of furan (6320 µg kg−1) was detected in ground coffee, while coffee-mix samples showed the lowest furan concentration (10 µg kg−1). Levels in brewed coffees indicated that, except for furfural, brewing by an espresso machine caused significant loss of furanic compounds.

Hydride generation coupled to microfunnel-assisted headspace liquid-phase microextraction for the determination of arsenic with UV-Vis spectrophotometry.

In this research, a microfunnel-assisted headspace liquid-phase microextraction technique has been used in combination with hydride generation to determine arsenic (As) by UV-Vis spectrophotometry. The method is based on the reduction of As to arsine (AsH3) in acidic media by sodium tetrahydroborate (NaBH4) followed by its subsequent reaction with silver diethyldithiocarbamate (AgDDC) to give an absorbing complex at 510nm. The complexing reagent (AgDDC) has been dissolved in a 1:1 (by the volume ratio) mixture of chloroform/chlorobenzene microdroplet and exposed to the generated gaseous arsine via a reversed microfunnel in the headspace of the sample solution. Several operating parameters affecting the performance of the method have been examined and optimized. Acetonitrile solvent has been added to the working samples as a sensitivity enhancement agent. Under the optimized operating conditions, the detection limit has been measured to be 0.2ngmL(-1) (based on 3sb/m criterion, n b = 8), and the calibration curve was linear in the range of 0.5-12ngmL(-1). The relative standard deviation for eight replicate measurements was 1.9%. Also, the effects of several potential interferences have been studied. The accuracy of the method was validated through the analysis of JR-1 geological standard reference material. The method has been successfully applied for the determination of arsenic in raw and spiked soft drink and water samples with the recoveries that ranged from 91 to 106%.

Rapid Analysis of the Bisphenol a in Slips of Store Receipts and ATM Machine with Head-Space Liquid-Phase Micro-Extraction Coupled to Gas Chromatography and Mass Spectrometry

A novel method has been developed for the determination of bisphenolA in slips of store receipts and ATM machine by head-space liquid-phase micro-extraction (HS-LPME) coupled with gas chromatography-mass spectrometry (GC-MS). The variable experimental conditions for the HS-LPME extraction process were optimized. The optimal conditions were using 2ul of toluene as organic solvent drop, 0.5g of the amount of sample and 1.0cm of the depth of micro-drop from the surface of the sample. After extracting for 10 min and detection limit of 1-100mg·L-1. Detection limit (3 S/N) of the method was found to be 0.3mg·L-1, precision and recovery of these methods were tested giving values of RSDs (n=6) less than 4.49%; and of recovery in th range of 98.80%-99.47%. The method shows advantages of simplicity, high sensitivity and high performance extraction to be in line with the analytical standard of the international organic pollutant.