催化动力学-流动注射停流分光光度法测定微量汞的研究

设计了分光光度自动分析系统的硬、软件 ,利用汞 ( )对藏红 T-碘化钾体系的催化褪色作用 ,建立了微量汞的催化动力学 -流动注射停流分光光度自动测定方法。Hg( )含量在 0～ 6.0 μg/m L范围内符合比尔定律 ,检出限为 3.5×1 0 -7g/m L,分析频率为 2 0 s/h。方法用于合成样品及污水中汞的测定 ,回收率为95.6%和 98.5% ,相对标准偏差为 5.1 %和 4.5% ( n=9     

Development and validation of RP-HPLC method for the determination of stigmasterol in the botanical extract of Ficus deltoidea

A simple, rapid, accurate and precise RP-HPLC method was developed for the determination of stigmasterol in botanical extract of Ficus deltoidea. Separation was achieved with acetonitrile and acetic acid in water (75:25% v/v) in isocratic mode at 210?nm. Single sharp peak of standard stigmasterol was detected at retention time 3.17?min which overlay with the peak of plant extract at 3.14?min. The calibration curve was found to be linear in a concentration range of 2–10?μg/ml with correlation coefficient of 0.998. The LOD and LOQ were found to be 1.50?μg/ml and 4.55?μg/ml respectively. Accuracy and precision was determined with overall recovery of 99.6–100.1% for stigmasterol and RSD values in both intra-day and inter-day repeatability assay lesser than 0.340%, respectively. The robustness study also indicated that there is no influence of minor changes in detecting wavelength and flow rate of mobile phase on the response.     

Determination of total and methyl mercury in human permanent healthy teeth by electrothermal atomic absorption spectrometry after extraction in organic phase

A simple and sensitive method has been developed for determination of inorganic and methyl mercury in biological samples by ETAAS. For determination of methyl mercury; it was transferred to toluene phase by acid leaching extraction method. For total mercury after digestion of samples; it was extracted to toluene phase by means of the chelating agent diethyldithiocarbamate. Formation of complex between MeHg and diethyldithiocarbamate enhance the MeHg signal and increases the reproducibility. Furthermore, Pd-DDC was used as modifier for both mercury and methyl mercury determinations. The optimization performance was independently carried out by modifying the parameters such as temperature of mineralization, atomization and gas flow rate for methylmercury and inorganic mercury in ETAAS. The limits of detection were 0.15 and 0.12 μg g⁻¹ for methyl mercury and total mercury, respectively. The repeatability of the measurements of whole procedure were 15.8% for methyl mercury and 16.9% for total mercury determination. The accuracy of the method has been investigated by means of spiking different amounts of methylmercury and inorganic mercury to the samples. The recoveries were found within the range of 88-95% for methyl mercury and 85-92% for total mercury. For determination of total mercury, the method was validated by CVAAS. The obtained results by the present procedure were in good agreement with those of the CVAAS. The proposed method was applied for 30 human permanent healthy teeth (without filling) which significant positive correlations were found among number of amalgam filling and total mercury and MeHg.     

超高效液相色谱–串联质谱法测定生活饮用水中10种农药残留

采用超高效液相色谱–串联质谱法测定生活饮用水中10种农药残留。水样直接进样,选用Waters ACQUITY UPLC~BEH C_(18)柱分离,以乙腈–0.1%甲酸溶液为流动相进行梯度洗脱,质谱选用多反应监测模式分析,10种农药的质量浓度在0.5~50μg/L范围内与色谱峰面积呈线性相关,检出限(3S/N)在0.03~0.50μg/L之间,测定值的相对标准偏差在1.14%~9.91%之间,加标回收率在91.6%~107.1%之间。该法简便准确,适用于生活饮用水中农药残留的检测。     

Cloud point extraction for the determination of cadmium and lead employing sequential multi-element flame atomic absorption spectrometry

A cloud point extraction procedure for pre-concentration and determination of cadmium and lead in drinking water using sequential multi-element flame atomic absorption spectrometry is described. 4-(2-thiazolylazo)-orcinol (TAO) has been used as complexing agent and the micellar phase was obtained using the non-ionic surfactant octylphenoxypolyethoxyethanol (Triton X-114) and centrifugation. The conditions for reaction and extraction (surfactant concentration, reagent concentration, effect of incubation time, etc) were studied and the analytical characteristics of the method were determined. The method allows the determination of cadmium and lead with quantification limits of 0.30?µg?L^?1 and 2.6?µg?L^?1, respectively. A precision expressed as relative standard deviation (RSD, n?=?10) of 2.3% and 2.6% has been obtained for cadmium concentrations of 10?µg?L^?1 and 30?µg?L^?1, respectively, and RSD of 1.3% and 1.7% for lead concentrations of 10?µg?L^?1 and 30?µg?L^?1, respectively. The accuracy was confirmed by analysis of a natural water certified reference material. The method has been applied for the determination of cadmium and lead in drinking water samples collected in the cities of Ilhéus and Itabuna, Brazil. Recovery tests have also been performed for some samples, and results varied from 96 to 105% for cadmium and 97 to 106% for lead. The cadmium and lead concentrations found in these samples were always lower than the permissible maximum levels stipulated by World Health Organization and the Brazilian Government.     

On-line simultaneous pre-concentration procedure for the determination of cadmium and lead in drinking water employing sequential multi-element flame atomic absorption spectrometry

An on-line pre-concentration system for the sequential determination of cadmium and lead in drinking water by using fast sequential flame atomic absorption spectrometry (FS-FAAS) is proposed in this paper. Two minicolums of polyurethane foam loaded with 2-(6-methyl-2-benzothiazolylazo)-orcinol (Me-BTAO) were used as sorptive pre-concentration media for cadmium and lead. The analytical procedure involves the quantitative uptake of both analyte species by on-column chelation with Me-BTAO during sample loading followed by sequential elution of the analytes with 1.0?mol?L^?1 hydrochloric acid and determination by FS-FAAS. The optimisation of the entire analytical procedure was performed using a Box–Behnken multivariate design utilising the sampling flow rate, sample pH and buffer concentration as experimental variables.

The proposed flow-based method featured detection limits (3σ) of 0.08 and 0.51?µg?L^?1 for cadmium and lead, respectively, precision expressed as relative standard deviation (RSD) of 1.63% and 3.87% (n?=?7) for cadmium at the 2.0?µg?L^?1 and 10.0?µg?L^?1 levels, respectively, and RSD of 6.34% and 3.26% (n?=?7) for lead at the 5.0?µg?L^?1 and 30.0?µg?L^?1 levels, respectively. The enrichment factors achieved were 38.6 and 30.0 for cadmium and lead, respectively, using a sample volume of 10.0?mL. The sampling frequency was 45 samples per hour. The accuracy was confirmed by analysis of a certified reference material, namely, SRM 1643d (Trace elements in natural water). The optimised method was applied to the determination of cadmium and lead in drinking water samples collected in Santo Amaro da Purificação City, Bahia, Brazil.     

Validation of a digestion system using a digester block/cold finger system for the determination of lead in vegetable foods by electrothermal atomic absorption spectrometry

This paper presents the validation of a system for sample digestion using a digester block/cold finger to determine the lead content in vegetables by electrothermal atomic absorption spectrometry (ETAAS). After mineralization, lead contents were determined by ETAAS using a calibration curve based on aqueous standards prepared in 2.60 M nitric acid solutions containing 5 microg ammonium phosphate as chemical modifier. A pyrolysis temperature of 900 degrees C and atomization temperature of 2000 degrees C were used. This method allowed the determination of lead with a characteristic mass of 35 pg; LOD and LOQ of 0.6 and 2 nglg, respectively, were found. The precision was investigated in terms of reproducibility and repeatability. Reproducibility was estimated by analysis of nine different portions of a certified reference material (CRM) of spinach leaves, and the repeatability was determined through the analysis of nine aliquots of the same solution. The reproducibility and repeatability were found to be 4.27 and 2.94% RSD, respectively. The accuracy was confirmed by analysis of whole meal flour, spinach leaves, and orchard leaves CRMs, all furnished by the National Institute of Standards and Technology. Lead contents were measured using the newly developed technique in 11 different potato samples. The lead contents ranged from 12.80 to 69.27 ng/g, with an average value of 28.59 ng/g. These values were in agreement with data reported in the literature.     

原子荧光法测定饮用水中汞

汞含量是生活用水中的重要毒理学指标.将水中汞在酸性介质中消解,被硼氢化钠还原成原子态,用原子荧光法测定.方法的检出限为1.1×10-3μg/L,线性范围为1.2×10-2μg/L~1.20μg/L,相对标准偏差为6.3%,加标回收率87.6%~112.5%.     

Determination of Fluorescent Whitening Agents in Infant Clothes and Paper Materials by Ion‐Pair Chromatography and Fluorescence Detection

A simple and rapid method was developed to simultaneously determine four stilbene‐type disulfonate and one distyrylbiphenyl‐type fluorescent whitening agents (FWAs) in infant clothes and paper materials by ion‐pair chromatography. FWAs were extracted from cloth and papers samples using a hot‐water extraction. The aqueous extract was then mixed with ion‐pair reagent, extracted with C₁₈‐SPE cartridges and eluted with methanol. The contents of FWAs were determined by an isocratic ion‐pair chromatography with RP‐C₁₈ column and equipped with fluorescence detection. Limits of quantitation were 0.04 to 0.45 ng/g in 10 g of samples. Recovery of FWAs in spiked infant cloth and paper samples was between 76 to 92% and precision (RSD) ranging from 2.0 to 4.0%. Analysis of three infant clothes and six paper materials found concentrations of selected FWAs ranging between n.d. to 24 μg/g and n.d. to 3.8 μg/g, respectively.     

Liquid chromatographic analysis of vitamin B6 in reconstituted infant formula: collaborative study

A liquid chromatographic (LC) method was validated for the determination of total vitamin B6 in infant formula. Total vitamin B6 was quantified by converting the phosphorylated and free vitamers into pyridoxine. Pyridoxine was determined by ion pair reversed-phase LC with fluorescence detection. The method was subjected to an AOAC collaborative study involving a factory-manufactured, milk- and soy-based infant formula. Each was spiked at 3 concentrations in the range of 0-1 microg/g and sent as blind duplicate to participant laboratories. Nine laboratories returned valid data which were statistically analyzed for outliers and precision parameters. The repeatability relative standard deviation (RSD(r)) ranges were 2.0-4.0 and 3.5-5.9% for fortified milk- and soy-based formulas, respectively. The reproducibility relative standard deviation (RSD(R)) ranges were 8.2-8.4 and 6.7-11.2% for fortified milk- and soy-based formulas, respectively. HORRAT values ranged from 0.42 to 0.53, indicating that the precision of the method is acceptable. The mean RSD(r):RSD(R) values were 0.60 and 0.55 for milk- and soy-based formulas, respectively. As expected, RSDs for the unfortified samples were higher, but their HORRAT values (0.81 and 2.06) helped define a realistic limit of quantitation as 0.05 microg/g. Recovery data were quantitative and varied between 81.4 and 98.0% (mean = 89.8%) for each of 6 spiked materials.     

Selective flow injection analysis of ultra-trace amounts of Cr(VI), preconcentration of it by solvent extraction, and determination by electrothermal atomic absorption spectrometry (ETAAS)

A rapid, robust, sensitive and selective time-based flow injection (FI) on-line solvent extraction system interfaced with electrothermal atomic absorption spectrometry (ETAAS) is described for analyzing ultra-trace amounts of Cr(VI). The sample is initially mixed on-line with isobutyl methyl ketone (IBMK). The Cr(VI) is complexed by reaction with ammonium pyrrolidine dithiocarbamate (APDC), and the non-charged Cr(VI)–PDC chelate formed is extracted into IBMK in a knotted reactor made from PTFE tubing. The organic extractant is separated from the aqueous phase by a gravity phase separator with a small conical cavity and delivered into a collector tube, from which 55 μl organic concentrate is subsequently introduced via an air flow into the graphite tube of the ETAAS instrument. The operations of the FI-system and the ETAAS detector are synchronously coupled. A significant advantage of the approach is that matrix constituents, such as high salt contents, effectively are eliminated. The extraction procedure was optimized by a simplex approach. A central composite design was subsequently employed to verify the estimated operational optimum. An 18-fold enhancement in sensitivity of Cr(VI) was achieved after preconcentration for 99 s at a sample flow rate of 5.5 ml min⁻¹, as compared to direct introduction of 55 μl of sample, yielding a detection limit (3σ) of 3.3 ng l⁻¹. The sampling frequency was 24.2 samples h⁻¹. The proposed method was successfully evaluated by analyzing a NIST Cr(VI)-reference material, synthetic seawater and waste waters, and waste water samples from an incineration plant and a desulphurization plant, respectively.     

Coupled multisyringe flow injection/reactor tank for the spectrophotometric detection of azinphos methyl in water samples

A multisyringe flow injection system with spectrophotometric detection is presented as a fast, robust and low-reagent consumption system for the determination of azinphos methyl (AzMe) in water samples. Determination is based on the Griess reaction. The analyte is hydrolyzed and the reaction product reacts with nitrite in acid medium to form the diazonium salt that reacts further with 1-naphtol reagent to produce an azo compound. The azo derivative is spectrophotometrically monitored at 485 nm. The influence of several chemical and flow variables has been investigated. Under the optimum analytical conditions, the linearity of the calibration curve for AzMe ranges from 1 to 32 μg mL^?1. The detection limit is 0.17?µg mL^?1, and recoveries between 95 to 109% have been obtained. The repeatability (RSD) is 0.8% for a 10?μg mL^?1 solution, and the injection throughput is seven samples h^?1. The system has been satisfactorily applied to the determination of AzMe in spiked river and dam water samples. The results were in agreement at the 95% confidence level with those obtained by HPLC.     

Simultaneous pre-concentration procedure for the determination of cadmium and lead in drinking water employing sequential multi-element flame atomic absorption spectrometry

In this paper is proposed a simultaneous pre-concentration procedure using cloud point extraction for the determination of cadmium and lead in drinking water employing sequential multi-element flame atomic absorption spectrometry. The ligand used is 2-(2-thiazolylazo)-p-cresol (TAC) and the micellar phase is obtained using non-ionic surfactant octylphenoxypolyethoxyethanol (Triton X-114) and centrifugation.The optimization step was performed using two-level factorial design and Doehlert design. A multiple response function was established in order to get experimental conditions for simultaneous extraction of cadmium and lead.The method allows the determination of cadmium and lead with detection limits of 0.077 μg L^− 1 and 1.05 μg L^− 1 respectively, precision expressed as relative standard deviation (RSD) of 1.5 and 3.3% (n = 10) for cadmium concentrations of 30 μg L^− 1 and 50 μg L^− 1, respectively, and RSD of 1.8% and 2.7% for lead concentrations of 30 μg L^− 1 and 50 μg L^− 1, respectively. The accuracy was confirmed by analysis of a certified reference material of natural water.This method was applied for the determination of cadmium and lead in drinking water samples collected in Jaguaquara City, Brazil. Tests of addition/recovery were also performed for some samples and results varied from 95 to 104% for cadmium and 96 to 107% for lead. The cadmium and lead concentrations found in these samples were always lower than the permissible maximum levels stipulated by Brazilian Health Organization.     

Mercury determination in sediments by CVAAS after on line preconcentration by solid phase extraction with a sol-gel sorbent containing CYANEX 471X®

The development of a preconcentration method for the measurement of trace levels of mercury in digested sediments is described. Solid phase extraction (SPE) was used for the preconcentration of mercury coupled on-line by means of a flow injection (FI) system followed by cold vapour atomic absorption spectrometry (CVAAS) detection. The SPE was carried out through a column packed with a sorbent material containing triisobutylphosphine sulfide (CYANEX 471X®) as mercury extractant and prepared by the sol-gel process. The effects of FI variables (argon, eluent, and reductant flow rates, loading and elution times) as well as the eluent concentration on the analytical performance of the method were evaluated. The proposed method was validated under the optimum conditions. The calibration graph was linear from 0.05?µg?L^?1 to 3.0 µg?L^?1 of Hg. The detection limit (DL), based on three times the standard deviation of the blank measurement criterion, was 24?ng^?L^?1. The repeatability was 1.5% and 1.8% RSD (n?=?10) at concentrations of 0.5 and 1 µg?L^?1 of Hg, respectively. Method enrichment factors of 16 with a productivity of 30 samples h^?1 or 32 with a productivity of 17 samples h^?1 were achieved under selected conditions. Certified reference materials, inductively coupled plasma mass spectroscopy (ICP-MS) and cold vapour atomic fluorescence spectrometry (CVAFS), were used to evaluate the accuracy of the proposed method.     

Development and validation of a liquid chromatography tandem mass spectrometry method for the analysis of β-agonists in animal feed and drinking water

A reproducible, sensitive and selective multiresidue analytical method for seven β-agonists: clenbuterol (CBT), clenpenterol (CPT), ractopamine (RTP), brombuterol (BBT), mabuterol (MBT), mapenterol (MPT), and hydroxymethylclenbuterol (HMCBT) was developed and validated by using liquid chromatography tandem mass spectrometry (LC–MS/MS) in feed and drinking water samples. The validation was achieved according to the criteria laid down in the Commission Decision 2002/657/EC, however it was necessary to use minimum required performance limits (MRPLs) proposed by the Community Reference Laboratories (CRLs) due to the lack of maximum residue limits (MRLs) for β-agonists. By setting up these MRPLs, allows controlling their use in safe mode, since β-agonists are commonly used in veterinary medicine sometime in a fraudulent manner, for increasing the weigh of animals. Values set for both matrices studied are 50 μg/kg for animal feed, and a range from 0.2 to 10 μg/L for drinking water. CCα values calculated were under the MRPLs suggested; for drinking water the lowest value obtained was 0.12 μg/L, and for animal feed 0.87 μg/kg. Values for CCβ were ranged from 0.08 to 0.13 μg/L in drinking water and from 0.5 to 0.92 μg/kg in animal feed samples. The excellence values obtained, allowed us to conclude that the proposed analytical method is capable to control the β-agonists studied in both matrices and that it can be successfully applied and used as a routine method in laboratories of residue analysis of veterinary food control.     

Analysis of perchlorate, thiocyanate, nitrate and iodide in human amniotic fluid using ion chromatography and electrospray tandem mass spectrometry

Because of health concerns surrounding in utero exposure to perchlorate, we developed a sensitive and selective method for quantifying iodide, as well as perchlorate and other sodium-iodide symporter (NIS) inhibitors in human amniotic fluid using ion chromatography coupled with electrospray ionization tandem mass spectrometry. Iodide and NIS inhibitors were quantified using a stable isotope-labeled internal standards (Cl¹⁸O₄⁻, S¹³CN⁻ and ¹⁵NO₃⁻ with excellent assay accuracy of 100%, 98%, 99%, 95% for perchlorate, thiocyanate, nitrate and iodide, respectively, in triplicate analysis of spiked amniotic fluid sample). Excellent analytical precision (<5.2% RSD for all analytes) was found when amniotic fluid quality control pools were repetitively analyzed for iodide and NIS-inhibitors. Selective chromatography and tandem mass spectrometry reduced the need for sample cleanup, resulting in a rugged and rapid method capable of routinely analyzing 75 samples/day. Analytical response was linear across the physiologically relevant concentration range for the analytes. Analysis of a set of 48 amniotic fluid samples identified the range and median levels for perchlorate (0.057-0.71, 0.18 μg/L), thiocyanate (<10-5860, 89 μg/L), nitrate (650-8900, 1620 μg/L) and iodide (1.7-170, 8.1 μg/L). This selective, sensitive, and rapid method will help assess exposure of the developing fetus to low levels of NIS-inhibitors and their potential to inhibit thyroid function.     

Studies on sorption of uranium on chitin: a solid-state extractant application for removal of uranium from ground water

Studies were carried out to remove uranium from aqueous systems based on the solid phase extraction of uranium by powdered chitin. The effects of various parameters like pH, contact time, and amount of chitin for quantitative sorption of uranium on chitin have been studied. The sorption studies with spiked water samples and natural ground water samples showed that uranium was easily sorbed onto powdered chitin between pH 3 and 6. The effects of various cations and anions, which are present in the water samples, were studied. The method is simple, fast and environmental friendly and it is unaffected by the other ions present in the natural waters. The accuracy of the method was evaluated by applying the present method on ground water samples containing uranium in the range of 100–2,200 μg/L. The uranium remained in water samples is <20 μg/L after treatment with chitin, which is below the AERB limits given for uranium in drinking water. The values are an average of five replicate measurements, with an RSD of ±10 μg/L at 100 μg/L uranium in water samples.     

Preconcentration in micro-electromembrane extraction across free liquid membranes

Preconcentration potential of micro-electromembrane extraction (μ-EME) across free liquid membrane (FLM) was examined with an anionic and a cationic dye, 4,5-dihydroxy-3-(p-sulfophenylazo)-2,7-naphthalene disulfonic acid, trisodium salt (SPADNS) and phenosafranine, respectively. For the first time, it was shown that the spatial flexibility of FLMs enabled application of tailored extraction units with mutually different shapes and migration cross-sections for FLMs, donor and acceptor solutions. Thus, e.g. conical units enabled easy and reproducible formation of a three-phase extraction system (donor/FLM/acceptor) with sub-μL volumes of acceptor solutions as well as rapid and highly efficient preconcentration of the two dyes. Quantitative measurements of resulting solutions were carried out by UV–vis spectrophotometry and enrichment factors of up to 98 were achieved for μ-EMEs of 20 μM SPADNS (50 μL) preconcentrated into 0.5 μL of pure water across 1-pentanol at −150 V for 18 min. Visual monitoring of the entire extraction process (with USB microscope camera) was possible across transparent extraction units, moreover, important extraction parameters, such as FLM dimensions and donor-to-acceptor solution volume ratio, which determine the mechanical stability of the membrane and maximum enrichment factor, respectively, were readily adjusted. Combination of μ-EME across FLMs with capillary electrophoresis (CE) was further shown suitable for preconcentration and determination of perchlorate in drinking water samples. Good repeatability of the μ-EME-CE method (RSD values better than 9.5%), linear relationship for the analytical signal vs. concentration (r² better than 0.997) and enrichment factors of up to 30 were achieved for μ-EMEs of perchlorate across 1-pentanol and 1-hexanol based FLMs.     

Fast analysis of quaternary ammonium pesticides in food and beverages using cation‐exchange chromatography coupled with isotope‐dilution high‐resolution mass spectrometry

A fast separation based on cation‐exchange liquid chromatography coupled with high‐resolution mass spectrometry is proposed for simultaneous determination of chlormequat, difenzoquat, diquat, mepiquat and paraquat in several food and beverage commodities. Solid samples were extracted using a mixture of water/methanol/formic acid (69.6:30:0.4, v/v/v), while liquid samples were ten times diluted with the same solution. Separation was carried out on an experimental length‐modified IonPac CS17 column (2 × 15 mm²) that allowed the use of formic acid and acetonitrile as mobile phase. Detection limits for food and beverage matrices were established at 1.5 μg/L for chlormequat, difenzoquat and mepiquat, and 3 μg/L for diquat and paraquat, while for drinking water a pre‐analytical sample concentration allowed detection limits of 9 and 20 ng/L, respectively. Precision, as repeatability (RSD%), ranged from 0.2 to 24%, with a median value of 6%, and trueness, as recovery, ranged from 64 to 118%, with a median value of 96%. The method developed was successfully applied to investigate the presence of herbicide residues in commercial commodities (mineral water, orange juice, beer, tea, green coffee bean, toasted coffee powder, cocoa bean, white corn flour, rice and sugar samples).     

Ionic liquids dispersive liquid–liquid microextraction and HPLC‐atomic fluorescence spectrometric determination of mercury species in environmental waters

An ionic liquid (IL) based dispersive liquid–liquid microextraction combined with HPLC hydride generation atomic fluorescence spectrometry method for the preconcentration and determination of mercury species in environmental water samples is described. Four mercury species (MeHg⁺, EtHg⁺, PhHg⁺, and Hg²⁺) were complexed with dithionate and the neutral chelates were extracted into IL drops using dispersive liquid–liquid microextraction. Variables affecting the formation and extraction of mercury dithizonates were optimized. The optimum conditions found were as follows: IL‐type and amount, 0.05 g of 1‐octyl‐3‐methylimidazolium hexafluorophosphate; dispersive solvents type and amount, 500 μL of acetone; pH, 6; extraction time, 2 min; centrifugation time, 12 min; and no sodium chloride addition. Under the optimized conditions, the detection limits of the analytes were 0.031 μg/L for Hg²⁺, 0.016 μg/L for MeHg⁺, 0.024 μg/L for EtHg⁺, and 0.092 μg/L for PhHg⁺, respectively. The repeatability of the method, expressed as RSD, was between 1.4 and 5.2% (n = 10), and the average recoveries for spiked test were 96.9% for Hg²⁺, 90.9% for MeHg⁺, 90.5% for EtHg⁺, 92.3% for PhHg⁺, respectively. The developed method was successfully applied for the speciation of mercury in environmental water samples.