Material For Preconcentration Research Articles

Green Synthesis of Metal Nanoparticles and Magnetic Nanocomposites for Adsorption, Desorption and Preconcentration of Pb(II)

AbstractSynthesis, characterization, Pb(II) adsorption, recovery, preconcentration and reusability of different nanoadsorbents were investigated in detail. With green synthesis, silver, iron oxide and iron copper nanoparticles (AgNPs, Fe3O4NPs and Fe/CuNPs) were synthesized and modified with chitosan and alginate natural polymers to form nanocomposite beads (Fe3O4‐CS, Fe3O4−AT, Fe/Cu−CS and Fe/Cu−AT). When the adsorption efficiencies of the seven synthesized nanoadsorbents from the aqueous medium were compared, it was seen that the magnetic bimetallic Fe/Cu−CS beads provided the highest adsorption with 100 % efficiency for Pb(II). The adsorption mechanism, effects of temperature, initial lead ion concentration and pH of the solution on the Pb(II) adsorption capacity of Fe/Cu−CS beads were investigated. The recovery studies have shown that Fe/Cu−CS beads have good adsorption/desorption performance around 90 % of desorption was achieved with 5 mM HNO3. These results show that Fe/Cu−CS beads have potential to be a promising material for adsorption, preconcentration and desorption of Pb(II) from aqueous solution.

Rapid determination of malondialdehyde in serum samples using a porphyrin-functionalized magnetic graphene oxide electrochemical sensor

An electrochemical sensor based on a screen-printed carbon electrode (SPCE) modified with porphyrin-functionalized magnetic graphene oxide (TCPP-MGO) was developed for the sensitive and selective determination of malondialdehyde (MDA), an important biomarker of oxidative damage, in serum samples. The coupling of TCPP with MGO allows the exploitation of the magnetic properties of the material for separation, preconcentration, and manipulation of analyte, which is selectively captured onto the TCPP-MGO surface. The electron-transfer capability in the SPCE was improved through derivatization of MDA with diaminonaphthalene (DAN) (MDA-DAN). TCPP-MGO-SPCEs have been employed to monitor the differential pulse voltammetry (DVP) levels of the whole material, which is related to the amount of the captured analyte. Under optimum conditions, the nanocomposite-based sensing system has proved to be suitable for the monitoring of MDA, presenting a wide linear range (0.01–100 µM) with a correlation coefficient of 0.9996. The practical limit of quantification (P-LOQ) of the analyte was 0.010 µM, and the relative standard deviation (RSD) was 6.87% for 30 µM MDA concentration. Finally, the developed electrochemical sensor has demonstrated to be adequate for bioanalytical applications, presenting an excellent analytical performance for the routine monitoring of MDA in serum samples.Graphical abstract

Ti3AlC2 max phase- graphene oxide (GO) nanocomposite for selective solid phase microextraction of palladium in environmental samples and medical appliances prior to its detection with high-resolution continuum source flame atomic absorption spectrometry (HR-CS-FAAS)

Palladium is an important metal as it has a wide range of applications in different fields but can cause cancer in human beings. Therefore, precise quantification of palladium is important. For this purpose, new material Ti3AlC2 max phase having unique properties like high stability, thermal conductivity and environmental friendly has been synthesized. To increase its surface area of Ti3AlC2 max phase, graphene oxide (GO) has been incorporated to form Ti3AlC2 max phase GO nanocomposite. Ti3AlC2 max phase GO nanocomposite was used as solid phase extracting material for microextraction and preconcentration of Pd(II) in environmental samples and medical appliances. Characterization of the adsorbent was achieved by using fourier transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM), X-ray diffraction (XRD), energy dispersive X-ray (EDX) and surface area analyzer (SAA). All the parameters that influence the extraction efficiency of the adsorbent like solution pH, amount of adsorbent, volume of sample, vortex time, desorption condition and interferences effect were determined and optimized. The limit of detection (0.327 µg/L) and limit of quantification (1.09 µg/L) show that the method is highly sensitive. The relative standard deviation was calculated as 5.48 % for five repeated measurements, which shows that the developed method is reproducible. The method is highly efficient with large values of preconcentration factor (20) and enhancement factors (20). The method was validated by applying the method to real water samples, soil samples and medical appliances with satisfied recovery results (94–106 %).

Porous Hexagonal Boron Nitride as Solid-Phase Microextraction Coating Material for Extraction and Preconcentration of Polycyclic Aromatic Hydrocarbons from Soil Sample.

Sample pretreatment plays important role in the analysis and detection of trace pollutants in complex matrices, such as environmental and biological samples. The adsorption materials of sample pretreatment receive considerable attention, which has a significant effect on the sensitivity and selectivity of the analytical method. In this work, the porous hexagonal boron nitride (h-BN) was utilized as a coating material of solid-phase microextraction (SPME) to extract and preconcentrate polycyclic aromatic hydrocarbons (PAHs) prior to separation and detection with GC-FID. Attributed to the multiple interactions including hydrophobicity, hydrogen bonding and strong π–π interaction, the h-BN coating showed excellent extraction performance for PAHs. Under the optimal conditions, the method showed the linear relationship in the range of 0.1–50 ng mL−1 for acenaphthene, 0.05–50 ng mL−1 for pyrene, and 0.02–50 ng mL−1 for fluorene, phenanthrene and anthracene with a correlation coefficient (R2) not lower than 0.9910. The enrichment factors were achieved between 1526 and 4398 for PAHs with h-BN as SPME fiber coating. The detection limits were obtained in the range of 0.004–0.033 ng mL−1, which corresponds to 0.08–0.66 ng g−1 for soil. The method was successfully applied to analysis of real soil samples. The recoveries were determined between 78.0 and 120.0% for two soil samples. The results showed that h-BN material provided a promising alternative in sample pretreatment and analysis.

A controlled recognizing and releasing glycoprotein based on temperature-responsive phenylboronic microgels for colorimetric analysis of complex samples.

It is challenging to capture glycoprotein from complicated samples with both high specificity and high recovery. Herein, we synthesized temperature-responsive poly (N-isopropylacrylamide-4-vinylbenzeneboronic acid) (PNIPAM-VPBA) microgels having enhanced affinity capability towards glycoprotein, resulting signal amplification in colorimetric analysis subsequently. Through temperature control, the target glycoprotein can be captured and released by the reported microgels unbiasedly. The microgels fabricated were characterized in terms of particle size, phase transition temperature, and toxicity. It was revealed that obvious changes in the particle diameter ranged from 600 to 323nm between 25°C and 55°C, the volume transition temperature was close to human physiological temperature, and low toxicity towards HeLa cells after 24h incubation. Using glucose oxidase as a model target, the microgels were applied as adsorbent materials for preconcentration of glucose oxidase, resulting 22-fold signal enhancement and a limit of detection (LOD) as low as 16.7 U/L. In beer sample analysis, satisfied recoveries of 78.7%-101.6% with the relative standard deviations (RSDs) less than 7.2% was observed. Subsequently, the microgels were combined with enzyme-linked immunosorbent assay (ELISA) for alpha fetoprotein (AFP) determination, by immobilizing horseradish peroxidase (HRP) and anti-AFP antibodies on the surface of microgels. A meaningful low concentration range of 2.5×10-2 to 1.0μg/L was obtained for AFP detection using the microgels based colorimetric method with a LOD of 8.4ng/L. In human serum sample analysis, good accuracy was achieved from method comparing with commercial ELISA kit, satisfied recoveries of 86.1%-96.4% with the RSDs less than 6.0% was observed. The proposed PNIPAM-VPBA microgels have great potential applications in the fields of food and clinical analysis.

Adsorptive colorimetric determination of chromium(VI) ions at ultratrace levels using amine functionalized mesoporous silica

There is an urgent need for a rapid, affordable and sensitive analytical method for periodic monitoring of heavy metals in water bodies. Herein, we report for the first time a versatile method for ultratrace level metal detection based on colorimetric sensing. The method integrates preconcentration using a nanomaterial with a colorimetric assay performed directly on the metal-enriched nanomaterial surface. This method circumvents the need for tedious sample pre-processing steps and the complex development of colorimetric probes, thereby reducing the complexity of the analytical procedure. The efficacy of the proposed method was demonstrated for chromium(VI) ions detection in water samples. Amine functionalized mesoporous silica (AMS) obtained from a one-pot synthesis was utilized as a pre-concentration material. The structural and chemical analysis of AMS was conducted to confirm its physico-chemical properties. The pre-concentration conditions were optimized to maximise the colorimetric signal. AMS exhibited a discernible colour change from white to purple (visible to the naked eye) for trace Cr(VI) ions concentration as low as 0.5 μg L−1. This method shows high selectivity for Cr(VI) ions with no colorimetric signal from other metal ions. We believe our method of analysis has a high scope for de-centralized monitoring of organic/inorganic pollutants in resource-constrained settings.

Determination of amount herbicide toxic fenpyroximate in surface water by analysis molecularly imprinted solid phase extraction method and relative error assessment using artificial neural network model

ABSTRACT This work describes the development of an analytical methodology to determine toxic fenpyroximate in surface water using molecularly imprinted polymers (MIPs) as the extraction and pre-concentration material, followed by high performance liquid chromatography. A new molecularly imprinted polymer, prepared following a non-covalent approach, was synthesised using toxic fenpyroximate as the template molecule, methacrylic acid as a functional monomer, and ethylene glycol dimethacrylate as a cross-linker. A method for the determination of traces of toxic fenpyroximate was developed using this polymer as the enrichment sorbent coupled with high performance liquid chromatography focusing on surface water samples. The calibration curve was linear in the range of 0.1 to 1.0 µg L−1. The standard deviation is 2.9%, and the detection limit of the method is 0.2 µg L−1 and r2 = 0.9869. The observed outcomes confirmed the suitability recovery and a very low detection limit for measuring toxic fenpyroximate. It was demonstrated that the proposed MI-SPE-HPLC method could be applied for direct determination of toxic fenpyroximate in surface water. The observed outcomes confirmed the suitability of the artificial neural network model as a tool for MSE (mean square error) of fenpyroximate on (MSEANN = 0.41, MSEFL = 0.36 and MSE ANFIS = 0.23) selectivity and permeability. It was demonstrated that the proposed MI-SPE-HPLC method could be applied for direct determination of toxic fenpyroximate in surface water.

Magnetic graphene molecularly imprinted polypyrrole polymer (MGO@MIPy) for electrochemical sensing of malondialdehyde in serum samples

A modified screen-printed carbon electrode (SPCE) has been designed and fabricated for the determination of malondialdehyde (MDA), an important biomarker of oxidative stress. Magnetic graphene oxide (MGO) was synthesized and coated by a molecularly imprinted polypyrrole (MIPy) for the preparation of a novel hybrid nanomaterial (MGO@MIPy). The nanocomposite has been characterized using different spectroscopic and imaging techniques. The coupling of MIPy with MGO allows the exploitation of the magnetic properties of the material for separation, preconcentration and manipulation of analyte which is selectively captured onto the MIPy surface of the nanocomposite. Besides, the derivatization of MDA with diaminonaphtalene (DAN) was carried out, resulting in a more electroactive molecule (MDA-DAN). MDA-DAN was used as template in the synthesis of MIPy. SPCEs were employed to monitor the differential pulse voltammetry (DVP) levels of the material, which is related to the amount of the captured analyte. Under optimum conditions, the nanocomposite-based sensing system has proved to be suitable for the monitoring of MDA, presenting a wide linear range (0.01–100 µM), high sensitivity (experimental LOQ = 0.01 µM) and precision (RSD = 4%). For validation purposes, three chicken serum samples were analysed by external calibration, obtaining recoveries values close to 100% for all the spiked tests. Finally, the developed electrochemical sensor demonstrated to be adequate for bioanalytical application, presenting an excellent analytical performance for the routine monitoring of MDA in serum samples.

New frontiers and prospects of metal-organic frameworks for removal, determination, and sensing of pesticides

Pesticides have been widely used in agriculture to control, reduce, and kill insects. Humans are also being using pesticides to control insidious animals in daily life. By these practices, a huge volume of pesticides is introduced to the environment. Despite broad-spectrum applicability, pesticides also have hazardous effects on both humans and animals at high and low concentrations. Long-term exposure to pesticides can cause different diseases, like leukemia, lymphoma, and cancers of the brain, breasts, prostate, testis, and ovaries. Reproductive disorders from pesticides include birth defects, stillbirth, spontaneous abortion, sterility, and infertility. Therefore, the application of determination and treatment methods for pre-concentration and removal of these toxic materials from the environment appears a vital concern. To date, different materials and approaches have been employed for these purposes. Among these approaches, multifunctional metal-organic frameworks (MOFs)-assisted adsorption and determination processes have always been in the spotlight. These facts are due to exclusive properties of MOFs in terms of the crystallinity, large surface area, high chemical, and physical stability, and controllable structure as well as unique features of adsorption and determination process in terms of simple, easy, cheap, available method and ability to use in large and industrial scales. In the present work, we illustrate the exceptional features of MOFs as well as the possible mechanism for the adsorption of pesticides by MOFs. The use of these fantastic materials for pre-concentration and removal of pesticides are extensively explored. In addition, the performance of MOFs was compared with other adsorbents. Finally, the new frontiers and prospects of MOFs for the determination, sensing, and removal of pesticides are presented.

Sorption behavior of uranium from Sulfate media using purolite A400 as a strong base anion Exchange resin

ABSTRACT The sorption characteristics of uranium onto a strongly basic anion exchanger, Purolite A400, were investigated. The characteristics of Purolite A400, before and after sorption of uranium, were determined using scanning electron microscopy (SEM) and energetic-dispersive X-ray (EDX). The influence of the different parameters, which may affect the process of uranium sorption process, had been tracked. Specifically, impacts of initial uranium concentration, pH, contact time and temperature, on uranium removal, were studied. In addition, the sorption kinetics and equilibrium parameters were assessed. At the optimum conditions, the adsorption capacity of uranium was found to be nearly 117.6 mg/g. The kinetics and isotherm studies could show that the uranium sorption onto Purolite A400 is following the models of pseudo-second-order and Langmuir isotherm respectively. The thermodynamic parameters had indicated that the adsorption of uranium is an exothermic and spontaneous process. The detected results of uranium sorption could reveal that Purolite A400 is a suitable material for pre-concentration of uranium (VI) species from sulfate leach liquor.

Development of a Polypyrrole-Modified Graphite Electrode for Acetaminophen Determination

Nowadays, acetaminophen commonly known as paracetamol , has been one of the most used drugs for pain treatment. By now, there have been reported only two official methods for the determination of this pharmaceutical active: HPLC and direct titration. Other techniques have been also reported in literature, like: spectroscopy, capillary electrophoresis and electrochemical techniques, including biosensors, microelectrodes and modified electrodes, these last have additional advantages like economy, fast and reliable response, and high selective to acetaminophen . In the present work an electroanalytical low-cost technique is proposed for the selective quantification of acetaminophen determination. This selectivity is achieved by molecular imprinting of acetaminophen on a polypyrrole matrix, electrochemically sintetized on the surface of a graphite electrode. The polypyrrole matrix acts as a selective preconcentration material for acetaminophen wich is latter determined by Square Wave Voltammetry in a separate clean electrolyte.

Modified Merrifield’s resin materials used in capturing of Pb(II) ions in water

In this paper, we report the synthesis of three new adsorbent materials for the recovery of Pb(II) ions in aqueous media by immobilization of the 3′,4′,5,7-pentahydroxyflavone (quercetin) on the Merrifield resin. The Merrifield’s resin was modified with different length alkyl chain spacers arms (oxi-alkyl-OH with six, seven and ten methylene groups) to immobilize quercetin on the resin. Materials characterization was performed by IR spectroscopy, molecular fluorescence and elemental microanalysis. The conversion rates showed yields higher than 95%. The adsorption properties of the Pb(II) ions showed that the highest retention is observed into the range of 0.64 to 1.21 mg g−1 in a dynamic regime at pH 5. The optimal concentration of the HNO3 eluent was 1 mol l−1 with 10 ml as the elution volume, and the pre-concentration factor was 4. Finally, a 93% of Pb(II) recovered was obtained on water supply employing the MR6Q resin, which also present stable behaviour and reusability in sorption and desorption cycles. These results encourage the use of these materials for pre-concentration and determination of Pb (II) in water.

A sequential injection fluorimetric methodology with in-line solid phase extraction for biogenic amines screening in water

ABSTRACTA method for the screening of biogenic amines in waters, whose presence at some concentration levels potentially cause adverse effects on humans, was developed for the first time. A suitable and easy to operate system, with low reagent consumption was devised. The proposed flow-based system was divided into two analytical parts, preconcentration and derivatization of the biogenic amines. Solid phase extraction, using a Chelex 100 resin, was the newly chosen strategy for preconcentration of the analyte and also removal of possible matrix interferences. Fluorescamine was used as derivatization reagent for biogenic amines followed by fluorimetric detection. The influence of different sorbent materials for preconcentration and flow system parameters such as pH of standards and buffer, composition of the eluent solution, flow-rates, standard/sample volume, were studied. The interference of ammonia was assessed, and no interference was observed. The limits of detection and quantification were 1.7 and 5.6 µmol L−1, respectively. The developed system was applied to water samples and the recovery results were 98 ± 7%.

Efficient removal of uranium(VI) by layered double hydroxides supported nanoscale zero-valent iron: A combined experimental and spectroscopic studies

In this study, nanoscale zero-valent iron (nZVI) supported on layered double hydroxide (LDH) composite (LDH@nZVI) was prepared, characterized and applied to U(VI) scavenging in water. Removal of U(VI) as a function of pH, ionic strength, reaction time, initial concentrations of U(VI), and temperature were studied and compared with pure LDH and nZVI, the LDH@nZVI had best U(VI) removal efficiency owning to the excellent synergistic combination of LDH adsorption and nZVI reduction. XPS analysis found that surface oxygen functional groups and surface-bound Fe(II) played a critical role in U(VI) remediation. The large surface areas (334.0 m2/g), abundant functional groups (i.e., MO, CO and OH), rapid kinetics (adsorption equilibrium within 1 h) and excellent adsorption capacities (176 mg/g) indicating that LDH@nZVI can be considered as a potential material for preconcentration of U(VI) from sewage water.

Preconcentration techniques for trace explosive sensing

Trace sensing of explosive vapours is a method in humanitarian demining and Improvised Explosive Device (IED) detection that has received increasing attention recently, since accurate, fast, and reliable chemical detection is highly important for threat identification. However, trace molecule sampling in the field can be extremely difficult due to factors including weather, locale, and very low vapour pressure of the explosive. Preconcentration of target molecules onto a substrate can provide a method to collect higher amounts of analyte for analysis. We used the commercial fluoropolymer Aflas as a preconcentrator material to sorb explosive molecules to the surface, allowing subsequent detection of the explosives via the luminescence quenching response from the organic polymer Super Yellow. The preconcentration effect of Aflas was confirmed and characterised with 2,4-DNT, prior to field sampling being conducted at a test minefield in Croatia by placing preconcentration strips in the entrance of beehives, where honeybees have collected explosive materials during free-flying. In this work we show for the first time a method for confirmation of landmines combining honeybee colonies containing a preconcentration material and subsequent monitoring of luminescence quenching.

A new magnetic nanodiamond/graphene oxide hybrid (Fe3O4@ND@GO) material for pre-concentration and sensitive determination of sildenafil in alleged herbal aphrodisiacs by HPLC-DAD system

A sensitive analytical methodology was investigated to concentrate and determine of sildenafil citrate (SLC) present at trace level in herbal supplementary products. The proposed method is based on simple and sensitive pre-concentration of SLC by using magnetic solid phase extraction with new developed magnetic nanodiamond/graphene oxide hybrid (Fe3O4@ND@GO) material as a sorbent. Experimental variables affecting the extraction efficiency of SLC like; pH, sample volume, eluent type and volume, extraction time and amount of adsorbent were studied and optimized in detail. Determination of sildenafil citrate after magnetic solid phase extraction (MSPE) was carried out by HPLC-DAD system. The morphology, composition, and properties of the synthesized hybrid material was characterized by Fourier transform infrared spectrometry (FT-IR), Raman spectrometry (Raman), X-ray diffraction spectrometry (XRD), scanning electron microscopy (SEM), mapping photographs, zeta potential analyzer, and BET surface area analysis. Under optimized conditions, linear range was ranged from 5.00 to 250.00 ng mL−1 with R2 of 0.9952. The limit of detection (LOD) was 1.49 ng mL−1 and the recoveries at two spiked levels were ranged from 94.0 to 104.1% with the relative standard deviation (RSD) < 7.1% (n = 5). The enhancement factor (EF) was 86.9. The results show that the combination MSPE with HPLC-DAD is a suitable and sensitive method for the determination of SLC in real samples.

Rapid Determination of Trace Palladium in Active Pharmaceutical Ingredients by Magnetic Solid-Phase Extraction and Flame Atomic Absorption Spectrometry

Clutaraldehyde cross-linked magnetic chitosan nanoparticles were synthesized and used as an adsorbent for the dispersive solid-phase extraction of palladium in active pharmaceutical ingredients (APIs) prior to analysis by a flame atomic absorption spectrophotometer. FT-IR, X-ray diffraction, and TEM were used to characterize the adsorbent. Various parameters of experimental performance, such as adsorbent amount, pH, adsorption time, desorption solutions, coexisting ions, and adsorbent reusability, were investigated and optimized. Under the optimized conditions, good linearity was achieved in the 5.0–500 μg/L concentration range, with correlation coefficients of 0.9989. The limit of detection is 2.8 μg/L and the recoveries of spiked samples ranged from 91.7 to 97.6%. It was confirmed that the GMCNs nanocomposite was a promising adsorbing material for extraction and preconcentration of Pd in APIs.

Novel Isocyanate-Modified Carrageenan Polymer Materials: Preparation, Characterization and Application Adsorbent Materials of Pharmaceuticals.

The present study focused on the synthesis and application of novel isocyanate-modified carrageenan polymers as sorbent materials for pre-concentration and removal of diclofenac (DCF) and carbamazepine (CBZ) in different aqueous matrices (surface waters and wastewaters). The polymer materials were characterized using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Thermal Gravimetric Analysis (TGA) and Scanning Electron Microscopy (SEM). The effects on the adsorption behavior were studied, and the equilibrium data were fitted by the Langmuir and Freundlich models. The maximum adsorption capacity (Qmax) was determined by Langmuir–Freundlich model and was ranged for iota-carrageenan (iCAR) from 7.44 to 8.51 mg/g for CBZ and 23.41 to 35.78 mg/g for DCF and for kappa-carrageenan (kCAR) from 7.07 to 13.78 mg/g for CBZ and 22.66 to 49.29 mg/g for DCF. In the next step, dispersive solid phase extraction (D-SPE) methodology followed by liquid desorption and liquid chromatography mass spectrometry (LC/MS) has been developed and validated. The factors, which affect the performance of D-SPE, were investigated. Then, the optimization of extraction time, sorbent mass and eluent’s volume was carried out using a central composite design (CCD) and response surface methodology (RSM). Under the optimized conditions, good linear relationships have been achieved with the correlation coefficient (R2) varying from 0.9901 to 0.995. The limits of detections (LODs) and limits of quantifications (LOQs) ranged 0.042–0.090 μg/L and 0.137–0.298 μg/L, respectively. The results of the recoveries were 70–108% for both analytes, while the precisions were 2.8–17.5% were obtained, which indicated that the method was suitable for the analysis of both compounds in aqueous matrices.

Remediation techniques applied for aqueous system contaminated by toxic Chromium and Nickel ion

Heavy metals contamination in environment is a global problem. Environment is polluted by different toxic metals due to industrial sources and anthropogenic activities. Variety of methodologies has been applied for the purification of waste water. Thus, article mainly focuses on the current developments and applicability of various wastewater treatment techniques, i.e., adsorption, membrane filtration, ion exchange, electrochemical treatment and electrocoagulation. Also, development of new adsorbents especially selective adsorbent, i.e., ion imprinted polymeric materials for selective removal and pre-concentration of toxic Nickel (II) and Chromium (VI) ions has been discussed in detail.

Facile synthesis of polymer monolith functionalized with layered double hydroxide as effective preconcentration materials for fluorescent whitening agents

In the current study, a novel monolithic capillary column functionalized with layered double hydroxide (LDH) was developed and exploited for the separation and preconcentration of fluorescent whitening agents combined with high performance liquid chromatography. Mg-Al LDH was embedded in the poly(dimethyl diallyl ammonium chloride-ethylene dimethacrylate) monolith via in situ polymerization. The ratio of LDH introduced into the polymerization mixtures was finely investigated. The characteristic properties of LDH and functionalized monolith were carefully characterized using X-ray diffraction, scanning electron microscope, Fourier-transformed infrared spectra, and thermal gravimetric analysis. After optimizing various experimental parameters, the developed method was validated and applied to the determination of fluorescent whitening agents in mask essence samples.