Magnetic effervescent tablet-assisted ionic liquid dispersive liquid–liquid microextraction of selenium for speciation in foods and beverages

A novel, simple and rapid method based on magnetic effervescent tablet-assisted ionic liquid dispersive liquid–liquid microextraction (MEA-IL-DLLME) followed by graphite furnace atomic absorption spectrometry (GFAAS) determination was established for the speciation of selenium in various food and beverage samples. In the procedure, a special magnetic effervescent tablet containing CO₂ sources (sodium carbonate and sodium dihydrogenphosphate), ionic liquids and Fe₃O₄ magnetic nanoparticles (MNPs) was used to combine extractant dispersion and magnetic recovery procedures into a single step. The parameters influencing the microextraction efficiency, such as pH of the sample solution, volume of ionic liquid, amount of MNPs, concentration of the chelating agent, salt effect and matrix effect were investigated and optimised. Under the optimised conditions, the limits of detection (LODs) for Se(IV) were 0.021 μg l^–1 and the linear dynamic range was 0.05–5.0 μg l^–1. The relative standard deviation for seven replicate measurements of 1.0 μg l^–1 of Se(IV) was 2.9%. The accuracy of the developed method was evaluated by analysis of the standard reference materials (GBW10016 tea, GBW10017 milk powder, GBW10043 Liaoning rice, GBW10046 Henan wheat, GBW10048 celery). The proposed method was successfully applied to food and beverage samples including black tea, milk powder, mushroom, soybean, bamboo shoots, energy drink, bottled water, carbonated drink and mineral water for the speciation of Se(IV) and Se(VI) with satisfactory relative recoveries (92.0–108.1%).     

Ionic Liquid-Based Vortex-Assisted Liquid–Liquid Microextraction for Simultaneous Determination of Neonicotinoid Insecticides in Fruit Juice Samples

A simple, rapid, and effective method was developed for preconcentration of neonicotinoid insecticides including clothianidin, imidacloprid, acetamiprid, and thiacloprid in fruit juice samples. Room-temperature ionic liquids [C₄MIM][PF₆] can be used as green extractant phases in vortex-assisted liquid–liquid microextraction (VALLME), being compatible with high-performance liquid chromatographic systems. The effect of extraction parameters, including the addition of salt, volume of (C₄MIM)(PF₆), vortex time, and centrifugation time is identified as the key parameters of the method. Under the selected conditions, the high enrichment factors of 100 could be achieved with the limit of detection in the range of 0.25–0.30 ng mL^?1 and with the relative standard deviations of lower than 2.68 and 5.38 % for retention time and peak area, respectively. The proposed method was applied to the analysis of fruit juice samples, and the recoveries of the analytes ranged from 95 to 108 % and relative standard deviations were lower than 7 %. The developed method proposes advantages in reduction of the exposure danger to toxic organic solvents used in the conventional liquid–liquid extraction, simplicity of the extraction processes, rapidity, and sensitivity improvement.     

A rapid shaking-based ionic liquid dispersive liquid phase microextraction for the simultaneous determination of six synthetic food colourants in soft drinks,sugar- and gelatin-based confectionery by high-performance liquid chromatography

A novel and simple rapid shaking-based method of ionic liquid dispersive liquid phase microextraction for the determination of six synthetic food colourants (Tartrazine, Amaranth, Sunset Yellow, Allura Red, Ponceau 4R, and Erythrosine) in soft drinks, sugar- and gelatin-based confectionery was established. High-performance liquid chromatography coupled with an ultraviolet detector was used for the determinations. The extraction procedure did not require a dispersive solvent, heat, ultrasonication, or additional chemical reagents. 1-Octyl-3-methylimidazolium tetrafluoroborate ([C₈MIM][BF₄]) was dispersed in an aqueous sample solution as fine droplets by manual shaking, enabling the easier migration of analytes into the ionic liquid phase. Factors such as the [C₈MIM][BF₄] volume, sample pH, extraction time, and centrifugation time were investigated. Under the optimum experimental conditions, the proposed method showed excellent detection sensitivity with limits of detection (signal-to-noise ratio = 3) within 0.015–0.32 ng/mL. The method was also successfully used in analysing real food samples. Good spiked recoveries from 95.8%–104.5% were obtained.     

Validation of a liquid chromatography-tandem mass spectrometry method for the simultaneous determination of sulfonamides,trimethoprim and dapsone in muscle,egg, milk and honey

A quantitative multi-residue method that includes 13 sulfonamides, trimethoprim and dapsone was developed and validated according to Commission Decision 2002/657/EC for muscle, milk egg and honey samples. For all matrices, the same extraction procedure was used. Samples were extracted with an acetone/dichloromethane mixture and cleaned up on aromatic sulfonic acid (SO₃H) SPE cartridges. After elution and concentration steps, analytes were identified and quantified by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Data were acquired according to the multiple reaction-monitoring approach (MRM) and analytes were quantified both by the isotope dilution and the matrix-matched approaches calculating the response factors for the scanned product ions. The developed method shows good linearity, specificity, precision (repeatability and within-laboratory reproducibility), and trueness. Estimated CCβ for sulfonamides ranged between 5.6 and 8.2 µg kg^?1 for eggs, between 11.1 and 69.9 µg kg^?1 for milk, between 64.7 and 87.9 µg kg^?1 for muscle, and between 2.7 and 5.3 µg kg^?1 for honey. CCβ values for dapsone were 3.1, 0.6, 0.7 and 1.5 µg kg^?1 and for trimethoprim were 3.1, 6.7, 81.7 and 3.0 µg kg^?1 calculated for eggs, milk, muscle and honey, respectively. Recovery for all matrices was in the range from 89.1% and 109.7%. In matrix effect testing, no significant deviations were found between different samples of muscle and milk; however, a matrix effect was observed when testing different types of honey. The validation results demonstrate that the method is suitable for routine veterinary drug analysis and confirmation of suspect samples.     

Dispersive Liquid–Liquid Microextraction Followed by Magnetic Solid-Phase Extraction for Determination of Four Parabens in Beverage Samples by Ultra-performance Liquid Chromatography Tandem Mass Spectrometry

In this study, a two-step extraction technique was developed for extraction and preconcentration of parabens from beverage samples using ionic liquid dispersive liquid–liquid microextraction (IL-DLLME) and magnetic solid-phase extraction (MSPE). In this IL-DLLME followed by MSPE method, ionic liquid (IL, 1-octyl-3-methylimidazolium hexafluorophosphate) formed hydrophobic microdroplets in beverage samples as an extractant of parabens; after the IL-DLLME process was completed, graphene modified Fe₃O₄ nanoparticles (Fe₃O₄@G) were placed to adsorb and isolate IL from the sample solution. After the supernatant was carefully moved, acetonitrile was added to elute the IL containing parabens from Fe₃O₄@G. The experimental variables affecting the extraction procedure have been systematically studied. Under optimal conditions, the detection limits were less than 1.53 ng/mL and the linear detection ranges were 2–500 ng/mL (R ² ≥ 0.998) for these analytes. The recoveries for spiked samples were 58.8–89.2% and satisfactory precision (RSD ≤ 4.8%) were obtained.     

Rapid Determination of Trace Sulfonamides in Milk by Graphene Oxide-Based Magnetic Solid Phase Extraction Coupled with HPLC–MS/MS

A simple and rapid method based on magnetic solid-phase extraction (MSPE) combined with high-performance liquid chromatography coupled with triple quadrupole mass spectrometry (HPLC–MS/MS) was used for the determination of 15 sulfonamides from milk samples. The extraction and cleanup used a graphene oxide-based magnetic nanocomposite (Fe₃O₄@GO) as an adsorbent. Various experimental parameters that could affect the extraction efficiencies, such as the amount of Fe₃O₄@GO, the extraction time, the ionic strength of sample solution, and the type of eluent, were investigated. Under optimized experimental conditions, good linearity was observed in the range of 2.0 to 100.0 μg L^?1 for all of the analytes, with correlation coefficients (R²) ranging from 0.994 to 0.999. The limits of detection for the method ranged between 0.02 and 0.13 μg L^?1. Mean values of the relative standard deviation of intraday and interday precision ranging from 1.0 to 7.3 % and from 1.7 to 8.1 % were obtained, respectively. The average recoveries were between 73.4 and 97.4 % at three different spiked levels. It was confirmed that the Fe₃O₄@GO nanocomposite was an effective MSPE material for use in sulfonamide analyses in milk samples.     

Ionic Liquid-Based Surfactant Extraction Coupled with Magnetic Dispersive μ-Solid Phase Extraction for the Determination of Phthalate Esters in Packaging Milk Samples by HPLC

A highly selective sample cleanup procedure combining ionic liquid-based surfactant extraction (ILSE) and magnetic dispersive μ-solid phase extraction (MD-μ-SPE) was triumphantly developed for the synchronously extraction of four phthalate acid esters (PAEs) in packaging milk samples prior to high-performance liquid chromatography coupled with photodiode array detector (HPLC-DAD). In this ionic liquid (IL)-based surfactant method, 1-octyl-3-methylimidazolium hexafluorophosphate ([C₈MIM] [PF₆]) was used as extraction solvent, anionic surfactant sodium linear alkylbenzene sulfonate (LAS) was used as auxiliary extraction solvent, and then sodium chloride (NaCl) was mixed to drive phase separation. The synthesized hydrophobic diatomaceous earth-supported Fe₃O₄ magnetic nanoparticles (DSMNPs) were applied as an efficient adsorbent to retrieve the analyte-containing IL and LAS. Under the optimal extraction situations, good linearity of the approach was obtained in the concentration range from 10 to 1000 ng/mL for target analytes, and the preconcentration process was rapidly accomplished in 5 min. The limits of detection (LODs) based on a signal-to-noise ratio (S/N = 3) were ranged from 1.42 to 3.57 ng/mL with the relative standard deviations (RSDs) over the range of 1.84–3.56% (n = 5). The above-mentioned method was applied to the trace analysis of four PAEs including benzyl butyl phthalate (BBP), dicyclohexyl phthalate (DCHP), di-n-butyl phthalate (DBP), and di-n-octyl phthalate (DNOP) in packaging milk samples, and recoveries were between 89.8 and 99.7%.     

Surveillance study of novobiocin and phenylbutazone residues in raw bovine milk using liquid chromatography-tandem mass spectrometry

A simple method permitting the simultaneous determination of trace residues of novobiocin and phenylbutazone in raw milk samples using liquid chromatography-tandem mass spectrometry was developed. Raw milk samples were mixed with acetonitrile to facilitate the concurrent precipitation of milk proteins and extraction of both veterinary drugs. Without additional clean-up or concentration of the resulting extract, the analytes could be quantified at concentrations as low as 0.0025 and 0.001 µg ml^?1 for phenylbutazone and novobiocin, respectively. The analysis of a series of fortified raw milk samples at analyte concentrations ranging from 0.005 to 0.1 µg ml^?1 and from 0.01 to 0.2 µg ml^?1 for phenylbutazone and novobiocin, respectively, yielded average recoveries ranging from 89.2% to 104.3% with standard deviations below 7%. The analytical method was applied to the analysis of raw milk samples collected from transport trucks upon delivery at dairy-processing plants throughout Alberta, Canada. Novobiocin was detected in 13 of 1072 samples tested at concentrations ranging from 0.001 to 0.007 µg ml^?1. Phenylbutazone was not detected in any of the samples tested.     

Magnetic three-dimensional graphene solid-phase extraction of chlorophenols from honey samples

A novel magnetic three-dimensional graphene nano-composite (3D-G@Fe₃O₄) with a high surface area was synthesised by a vacuum freeze-dried method. Due to its high surface area, specific 3D nanoporous structure and excellent magnetic properties, it can be used as a magnetic solid-phase extraction adsorbent. Some chlorophenols in a honey samples were enriched by this nanocomposite prior to their determination by HPLC with ultraviolet detection. Factors that affect the extraction efficiency, such as the amount of 3D-G@Fe₃O₄, extraction time, sample pH, ionic strength and desorption conditions, were investigated and optimised. Under the optimum conditions, good linearity existed in the range of 10.0–1000.0 ng g^–1. The enrichment factors of the method for the analytes were in the range from 101 to 248. The limits of detection of the method (S/N = 3) were 1.0–1.5 ng g^–1. The recoveries of the method for the analytes at spiking levels of 100.0 and 400.0 ng g^–1 were in the range of 93.2–98.9%. The results showed that the proposed method is simple, reliable and sensitive. It will be a useful tool for the routine monitoring of chlorophenols in honey products.     

Determination of polycyclic aromatic hydrocarbons in Italian milk by HPLC with fluorescence detection

The presence of polycyclic aromatic hydrocarbons (PAHs) in Italian commercial milk samples is reported. The study was carried out on lactating (cow and goat) and plant (rice, soya, oat) milk. The quantitative determination involved liquid–liquid extraction of PAHs, a pre-concentration and determination by HPLC using a fluorescence detector. The recovery of analytes was in the range of 70–115%. The precision of the method was found to be between 6% and 24%. The detection limit ranged from 0.66 to 33.3 µg l^–1 corresponding to 0.03–1.66 µg kg^–1 milk (wet weight), at a signal-to-noise ratio of 3, depending on the compound. By this procedure, the levels of more volatile PAHs (two to three aromatic rings) were confirmed in 34 commercial milk and three plant milk samples, whereas benzo[a]pyrene was found only in five pasteurised milk samples at a mean concentration of 0.17 µg kg^–1 milk. These results provide evidence that PAH levels are influenced by heat treatments and skimming processes of milk production.     

Dispersive liquid–liquid microextraction combined with sweeping micellar electrokinetic chromatography for the determination of some neonicotinoid insecticides in cucumber samples

A rapid, simple and sensitive method has been developed for the analysis of some neonicotinoid insecticides in cucumber samples by using dispersive liquid–liquid microextraction (DLLME) coupled with sweeping in micellar electrokinetic chromatography (MEKC). Under optimised conditions, the enrichment factors were achieved in the range from 4000 to 10,000. The linearity of the method was in the range from 2.7 to 200 ng g⁻¹ for thiacloprid, acetamiprid and imidacloprid, and in the range from 4.0 to 200 ng g⁻¹ for imidaclothiz in cucumber samples, with the determination coefficients (r²) ranging from 0.9924 to 0.9968. The limits of detection (LODs, S/N = 3) ranged from 0.8 to 1.2 ng g⁻¹. The relative standard deviations (RSDs) at the concentration levels of 10.0 and 50.0 ng g⁻¹ each of the neonicotinoid insecticides in cucumber samples varied from 3.8% to 6.3%. The developed method has been successfully applied to the analysis of the neonicotinoid insecticides in cucumbers with a satisfactory result.     

Trace Analysis of Seven Neonicotinoid Insecticides in Bee Pollen by Solid–Liquid Extraction and Liquid Chromatography Coupled to Electrospray Ionization Mass Spectrometry

A new, fast, simple, and efficient sample treatment to extract seven neonicotinoid insecticides (acetamiprid, clothianidin, dinotefuran, imidacloprid, nitenpyram, thiacloprid, and thiamethoxam) in corbicular bee pollen has been developed. This procedure consisted of a solid–liquid extraction of the neonicotinoids from pollen with dichloromethane, followed by evaporation and reconstitution. Once the neonicotinoids were extracted, they were determined using a liquid chromatography coupled to an electrospray ionization mass spectrometry method. The method was validated in terms of selectivity, linearity, precision and recovery. The limits of detection and quantification were 0.4–2.8 μg/kg and 1.2–9.1 μg/kg, respectively, and the extraction recoveries were between 86 and 106 % in all cases. Finally, the proposed method was applied to analyze bee pollen samples collected from apiaries located close to fruit orchards in two Spanish regions, and traces of acetamiprid and imidacloprid were found in two samples.     

Magnetic solid-phase extraction coupled with HPLC for the determination of Allura Red in food and beverage samples

A magnetic solid-phase extraction (MSPE) protocol prior to HPLC was developed for the extraction and determination of Allura Red in food samples. Magnetic nanoparticles were coated with tetraethylorthosilicate and 3-aminopropyltriethoxysilane and modified by graphene. Scanning electron microscopy, transmission electron microscopy and Fourier-transform infrared spectrometry were used to characterise the graphene-functionalised sorbents; and the main parameters affecting the extraction such as sample volume, temperature, pH and time were investigated and established. Under optimised conditions, the pre-concentration factor of Allura Red was 200, and the calibration curve was linear at a concentration range of 5–1500 μg kg^?1. The LOD was 2 μg kg^?1, the limit of quantification was 7 μg kg^?1, and the relative standard deviation was 3.3%. The prepared MSPE procedure was simple and fast, and it was successfully applied for the determination of Allura Red in beverages, candy and jelly.     

Determination of patulin in apple juice using magnetic solid-phase extraction coupled with high-performance liquid chromatography

ABSTRACT

An efficient magnetic sorbent consisting of benzofuran-2-carboxylic acid-loaded magnetic nanocomposite was successfully synthesised for pre-concentration of patulin from apple juice. The prepared magnetic nanocomposite was characterised by scanning electron microscopy, transmission electron microscopy and Fourier-transform infrared spectroscopy. Determination of enriched patulin was performed by high-performance liquid chromatography. The best adsorption conditions were 40 mg of sorbent, 50 ml of apple juice sample, pH 5, ambient temperature and 25 min; the elution conditions were 500 μl methanol, pH 5, ambient temperature, and 4 min. Under optimised conditions, pre-concentration factor was 100, linearity range was 1–400 μg l^–1 of patulin, limit of detection was 0.15 μg l^–1 and limit of quantification was 0.5 μg l^–1. When samples were determined 20 times, the recovery was 93.9–102.6% and the relative standard deviation was below 5.3%. In terms of proposed procedure, the developed method was successfully applied for patulin detection in apple juice samples.     

A rapid liquid chromatography determination of free formaldehyde in cod

A rapid method for the determination of free formaldehyde in cod is described. It uses a simple water extraction of formaldehyde which is then derivatised with 2,4-dinitrophenylhydrazine (DNPH) to form a sensitive and specific chromophore for high-performance liquid chromatography (HPLC) detection. Although this formaldehyde derivative has been widely used in past tissue analysis, this paper describes an improved derivatisation procedure. The formation of the DNPH formaldehyde derivative has been shortened to 2 min and a stabilising buffer has been added to the derivative to increase its stability. The average recovery of free formaldehyde in spiked cod was 63% with an RSD of 15% over the range of 25–200 mg kg^?1 (n = 48). The HPLC procedure described here was also compared to a commercial qualitative procedure – a swab test for the determination of free formaldehyde in fish. Several positive samples were compared by both methods.     

Simultaneous Determination of Five Neonicotinoid Insecticides in Edible Fungi Using Ultrahigh-Performance Liquid Chromatography-Tandem Mass Spectrometry (UHPLC-MS/MS)

A robust analytical method for simultaneously determining five neonicotinoid insecticides (clothianidin, dinotefuran, imidacloprid, thiacloprid, and thiamethoxam) in commonly consumed edible fungi (Agaricus bisporus, Flammulina velutipes, Hypsizygus marmoreus, Lentinus edodes, and Pleurotus eryngii) was provided in the present study. Samples were pretreated using a modified QuEChERS (quick, easy, cheap, efficient, rugged, and safe) method with the detection of neonicotinoids by ultrahigh-performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS). A number of optimizations performed to sample pretreatment and detection conditions were discussed. Limits of detection (LODs) for all analytes in edible fungi were between 0.03 and 0.7 μg kg^?1, while limits of quantitation (LOQs) ranged from 0.1 to 2 μg kg^?1. Mean recoveries for clothianidin, dinotefuran, imidacloprid, thiacloprid, and thiamethoxam were in the range of 100.5–118.0, 73.9–89.5, 88.6–117.8, 72.9–121.8, and 98.9–117.2%, respectively, with RSDs less than 8.1%. This method could be used for fast screen of the five neonicotinoid insecticides in edible fungi for risk assessing aims.     

Analytical determination of bisphenol A (BPA) and bisphenol analogues in paper products by LC-MS/MS

ABSTRACT

In this study a sensitive analytical method based on liquid chromatography-electrospray tandem mass spectrometry (LC-MS/MS) was developed for the simultaneous analysis of bisphenol A (BPA), bisphenol AF (BPAF), bisphenol B (BPB), bisphenol E (BPE), bisphenol F (BPF) and bisphenol S in different paper and board products, including virgin fibre samples and recycled samples. Analytes were extracted from the paper matrix using a simple solvent extraction and chromatographic separation was performed on a C18 core-shell (100 mm x 2.1 mm i.d.; 1.7 µm particle size) column. The developed method showed good linearity (R² > 0.9921) for all analytes. Absolute recoveries ranged from 71 to 115% and precision in terms of reproducibility and repeatability (intra- and inter-day) yielded in relative standard deviations (RSDs) of less than 15.0% and 17.4%, respectively. The limit of detection (LOD) and limit of quantification (LOQ) for the different analytes ranged from 0.29 to 0.40 µg kg^?1 paper and from 1.09 to 1.32 µg kg^?1 paper, being in the same range for all analytes. Quantitation of the analytes was performed using the internal standard procedure, with concentrations of < LOQ to 9599 µg kg^?1 for the different analytes. Furthermore, a calculation of the maximum migration, assuming the ‘worst case’ scenario of 100% migration was performed.     

Method for the determination of cadmium,lead, nickel,cobalt and copper in seafood after dispersive liquid–liquid micro-extraction

A method using dispersive liquid–liquid micro-extraction (DLLME) and detection by inductively coupled plasma optical emission spectroscopy (ICP-OES) was developed for the determination of trace elements in seafood samples. The procedure allowed the simultaneous determination of Cd(II), Pb(II), Ni(II) Cu(II) and Co(II) after pre-concentration using sodium diethyldithiocarbamate (DDTC) as a chelating agent. Under optimised conditions, the method had a limit of detection (LOD) of 0.03, 0.11, 0.12, 0.18 and 0.12 µg l^?1 for Cd(II), Pb(II), Ni(II) Cu(II) and Co(II), respectively. The following enrichment factors were obtained: 16 (Cd), 34 (Pb), 20 (Ni) 34 (Cu) and 12 (Co). The procedure was applied for the determination of these elements in seafood (shrimp, mussel, bass and mullet) samples. The method is simple, efficient and easy to perform for the simultaneous determination of elements in seafood samples by ICP-OES.     

Determination of glyphosate,AMPA, and glufosinate in honey by online solid-phase extraction-liquid chromatography-tandem mass spectrometry

A simple method was developed for the simultaneous determination of glyphosate, its main degradation product (aminomethylphosphonic acid), and glufosinate in honey. Aqueous honey solutions were derivatised offline prior to direct analysis of the target analytes using online solid-phase extraction coupled to liquid chromatography-tandem mass spectrometry. Using the developed procedure, accuracies ranging from 95.2% to 105.3% were observed for all analytes at fortification levels of 5, 50, and 150 μg kg^?1 with intra-day precisions ranging from 1.6% to 7.2%. The limit of quantitation (LOQ) was 1 μg kg^?1 for each analyte. Two hundred honey samples were analysed for the three analytes with AMPA and glyphosate being most frequently detected (99.0% and 98.5% of samples tested, respectively). The concentrations of glyphosate were found to range from <1 to 49.8 μg kg^?1 while those of its degradation product ranged from <1 to 50.1 μg kg^?1. The ratio of glyphosate to AMPA was found to vary significantly amongst the samples where both analytes were present above the LOQ. Glufosinate was detected in 125 of 200 samples up to a maximum concentration of 33.0 μg kg^?1.     

Selenium Speciation in Rice Samples by Magnetic Ionic Liquid-Based Up-and-Down-Shaker-Assisted Dispersive Liquid-Liquid Microextraction Coupled to Graphite Furnace Atomic Absorption Spectrometry

A novel and sensitive magnetic ionic liquid-based up-and-down-shaker-assisted dispersive liquid-liquid microextraction (MIL-UDSA-DLLME) was developed for the graphite furnace atomic absorption spectrometric measurement of inorganic selenium speciation from various rice matrixes. In the first microextraction step, the magnetic ionic liquid (1-butyl-3-methylimidazolium tetrachloroferrate, [C₄mim][FeCl₄]) was selected to extract the complex of Se(IV) and 2,3-diaminonaphthalene from aqueous solution by the assistance of up-and-down-shaker vortex agitator. After the microextraction step, the magnetic ionic liquid containing target analytes was collected at the bottom of the tube by applying an external magnetic field around the test tube. Under the optimized conditions, the method present has low detection limit (0.018 μg L^?1), wide linear dynamic range (0.03–10 μg L^?1), and good repeatability (<3.0%, n = 10) for Se(IV). The proposed methodology was applied for separation and preconcentration of inorganic selenium in standard reference materials including GBW10010 rice, GBW10043 Liaoning rice, and GBW10045 Hunan rice with satisfactory results. The developed methodology was also successfully used for the speciation of Se(IV) and Se(VI) in different rice samples with the relative recoveries within the acceptable range of 94.9–104.8% for the addition recovery tests.