磷钼杂多酸-有机溶剂多元胶束络合物显色测定微量磷

研究发现,磷钼杂多酸与罗丹明B、丙酮、明胶、聚乙烯醇(PVA)形成的有机溶剂胶束包合络合物在592nm处显色。以试剂空白为参比,用以测定微量的磷,其表观摩尔吸光系数为2.0×105L·mol-1·cm-1。磷的质量浓度在0～0 40μg mL服从比尔定律,回归方程为A=0.256ρ 0.010,相关系数r=0.9991。吸光度相对误差在±5%以内,1000倍的Fe3 ,Al3 ;600倍的Mn2 ,Cd2 ;500倍的Cu2 ,Ni2 ;60倍的Cr3 对测定无干扰。该方法用于洗衣粉中微量磷的测定。     

高效液相色谱-质谱联用法检测猪肉中5种青霉素的残留量

建立了高效液相色谱与质谱联用法测定猪肉中5种青霉素类药物残留的方法.样品采用体积分数0.5%的乙酸提取,匀浆离心分离后通过XAD-2固相萃取柱净化,甲醇洗脱后,用质谱检测器检测.采用Agilent HC-C18色谱柱(250 mm×4.6 mm i.d.,5 μm),以体积分数0.1%NH3·H2O和乙腈为流动相进行梯度洗脱.在添加水平为0.1、0.2、0.5 mg/kg时,回收率在52%～82.8%之间,相对标准偏差在3.4%～9.2%之间,对于不同的药物,方法的检出限为0.001～0.005 mg/kg.该方法适合于猪肉组织中青霉素类药物残留量的检测.     

Analysis of veterinary drug residues in cheese by ultra‐high‐performance LC coupled to triple quadrupole MS/MS

A simple, reliable, and fast multiresidue method has been developed for the determination of 17 veterinary drugs belonging to several families (macrolides, sulfonamides, and anthelmintics) in cheese at trace levels. Ultra‐high‐performance LC coupled to MS/MS has been used for the analysis of these compounds in less than 9 min. Veterinary drug residues have been extracted from cheese samples using a QuEChERS (quick, easy, cheap, effective, rugged, and safe)‐based extraction procedure without applying any further clean‐up step. Matrix‐matched calibration was used for quantification and recoveries were calculated at three concentration levels (10, 50, and 100 μg/kg). The obtained values ranged from 70 to 110% for the selected compounds except for tylosin and josamycin at 100 μg/kg (111.7 and 112.7%, respectively). Intra‐ and interday precision were also evaluated and RSDs were lower than 25% in all the cases. LOQs ranged from 0.3 μg/kg (for thiabendazole, oxfendazole, mebendazole, josamycin, and fenbendazole) to 10.5 μg/kg (abamectin), whereas decision limit and detection capability ranged from 2.3 (thiabendazole) to 11.3 (abamectin) and 4.2 (thiabendazole) to 14.3 μg/kg (abamectin), respectively. Finally, 13 samples were analyzed and traces of thiabendazole were detected in two different cheeses.     

Determination of trace amounts of lead and cadmium using a bismuth/glassy carbon composite electrode

We examined the use of a bismuth-glassy carbon (Bi/C) composite electrode for the determination of trace amounts of lead and cadmium. Incorporated bismuth powder in the composite electrode was electrochemically dissolved in 0.1 M acetate buffer (pH 4.5) where nanosized bismuth particles were deposited on the glassy carbon at the reduction potential. The anodic stripping voltammetry on the Bi/C composite electrode exhibited well-defined, sharp and undistorted peaks with a favorable resolution for lead and cadmium. Comparing a non-oxidized Bi/C composite electrode with an in-situ plated bismuth film electrode, the Bi/C composite electrode exhibited superior performance due to its much larger surface area. The limit of detection was 0.41 μg/L for lead and 0.49 μg/L for cadmium. Based on this study, we are able to conclude that various types of composite electrodes for electroanalytical applications can be developed with a prudent combination of electrode materials.     

Simultaneous determination of pyrethroids from pesticide residues in porcine muscle and pasteurized milk using GC

The principal goal of this work was to develop an efficient method for the simultaneous determination of four pyrethroid (PYR) insecticides, cyfluthrin, cyhalothrin, cypermethrin, and deltamethrin, in porcine muscle and pasteurized milk using liquid–liquid extraction (LLE). Sample extraction was carried out with and without additional column cleanup procedures, and the final determination was made using GC with electron‐capture detector (ECD). The pesticide identity was confirmed using GC‐MS in the SIM mode. Since there were minor differences between the extraction procedures, extraction without the additional cleanup procedure was used throughout the work. The method was validated by fortifying blank samples with half, two, and four times the maximum residue limit (MRL) of each PYR. The average recoveries (n = 6) ranged from 83.5 to 99.2% and 82.9 to 109% in porcine muscle and pasteurized milk, respectively. The repeatability of measurements expressed as RSDs, was in the range of 1.7–11.9 and 1.5–10.3% in porcine muscle and pasteurized milk, respectively. The LODs ranged from 3.3 to 9 and 3 to 8.1 ppm, whereas the LOQs ranged from 10 to 27.4 and 9 to 24.6 ppm, in porcine muscle and pasteurized milk, respectively. The applicability of the method was demonstrated by analyzing real samples collected from major cities in the Republic of Korea. No residues of the selected pesticides were detected in any of the samples.     

Determination of spiramycin and neospiramycin antibiotic residues in raw milk using LC/ESI‐MS/MS and solid‐phase extraction

A simple confirmatory method for the determination of spiramycin and its metabolite neospiramycin in raw milk using LC ESI MS/MS is presented. Macrolide residues in raw milk were extracted by ACN, and sample extracts were further cleaned up and concentrated using SPE cartridges. Both spiramycin and neospiramycin were protonated in electrospray positive ion mode to form singly and/or doubly charged pseudomolecular ions. Data acquisition was achieved using multiple reaction monitoring, i.e., two transitions, for quantification and confirmation. Matrix‐matched standard calibration curves were utilized to achieve the best accuracy for the method. The method performance was evaluated according to both a conventional validation procedure and a designed experimental result. The measurement uncertainty arising from accuracy and precision was estimated. The method accuracy, expressed as a percentage of an overall recovery, was from 82.1 to 108.8%, and its intermediate precision was less than 20%. LC/ESI‐MS/MS method LODs (S/N ? 3:1) of spiramycin and neospiramycin were less than 1.0 μg/kg.     

Simultaneous determination of trace amounts of sulphur hexafluoride and cyclic perfluorocarbons in reservoir samples by gas chromatography

Summary Both sulphur hexafluoride and a group of compounds among the perfluorinated cyclic hydrocarbons: perfluorodimethyl cyclobutane, perfluoromethyl cyclopentane, perfluoromethyl cyclohexane and the 1,2- and 1,3-isomers of perfluordimethyl cyclohexane are well known to be good gas tracers, in various applications. Unfortunately different methods have been used for the analysis of SF₆ and the perfluorocarbons. Therefore, in many cases, the analytical costs may have hindered the use of both SF₆ and the perfluorocarbons in the same tracer experiments. The analytical method described in this paper enables the determination of both types of gas tracer in one single run. The new method has already replaced two former methods and was used to run the gas tracer analysis routinely, proving the reliability of the method.     

Rapid and sensitive LC‐MS/MS method for determination of megestrol acetate in human plasma: application to a human pharmacokinetic study

A rapid, simple and fully validated LC‐MS/MS method was developed and validated for the determination of megestrol acetate in human plasma using tolbutamide as an internal standard (IS) after one‐step liquid–liquid extraction with methyl‐tert‐butyl‐ether. Detection was performed using electrospray ionization in positive ion multiple reaction monitoring mode by monitoring the transitions m/z 385.5 → 267.1 for megestrol acetate and m/z 271.4 → 155.1 for IS. Chromatographic separation was performed on a YMC Hydrosphere C₁₈ column with an isocratic mobile phase, which consisted of 10 mm ammonium formate buffer (adjusted to pH 5.0 with formic acid)–methanol (60:40, v/v) at a flow rate of 0.4 mL/min. The achieved lower limit of quantitation (LLOQ) was 1 ng/mL (signal‐to‐noise ratio > 10) and the standard calibration curve for megestrol acetate was linear (r > 0.99) over the studied concentration range (1–2000 ng/mL). The proposed method was fully validated by determining its specificity, linearity, LLOQ, intra‐ and inter‐day precision and accuracy, recovery, matrix effect and stability. The validated LC‐MS/MS method was successfully applied for the evaluation of pharmacokinetic parameters of megestrol acetate after oral administration of a single dose 800 mg of megestrol acetate (Megace?) to five healthy Korean male volunteers under fed conditions. Copyright © 2012 John Wiley & Sons, Ltd.     

Determination of trace amounts of sodium and lithium in zirconium dioxide (ZrO2) using liquid electrode plasma optical emission spectrometry

This paper describes a quantitative measurement of trace elements (Na, Li) in high purity zirconium dioxide powder using liquid electrode plasma optical emission spectrometry (LEP-OES). Conventionally, for such type of measurements, inductively coupled plasma optical emission spectrometry (ICP-OES) is frequently employed. The detection limits of elements in zirconium by ICP-OES are degraded due to the spectra interference between the trace elements and zirconium of the matrix, because zirconium is a line rich element in spectra obtained by ICP-OES. LEP-OES is an elemental analysis method developed by the authors. The measurement principle is simple, as follows. Sample solution is put into a narrow channel on a small cuvette and voltage pulse is applied from both ends of the channel. At the center of the channel which is made narrower, the voltage and current are concentrated there, and plasma is generated. From the emission of the plasma, the quantitative analysis of the elements in the solution is achieved. The LEP-OES has the property that the emission of zirconium is relatively weak, so that highly sensitive measurement of trace elements in zirconium matrix can be conducted without interference. Sample solution is prepared by dissolving high purity zirconium dioxide powder and trace amounts of Na or Li with sulfuric acid. The voltage dependence and the pulse width dependence of optical emission spectra are also investigated. With increase of the voltage or the pulse width, the ratio of emission intensities of Na to those of hydrogen increases. This suggests that the ratio of sensitivity of two elements is variable, that means the element selectivity is controllable to some extent by the measurement conditions in LEP-OES. In the case of Na and H, the ratio can be controlled from 7.4 to 21.6%. Finally, the detection limits (3S.D.) of the trace elements, Na and Li, in 4000 μg g⁻¹ zirconium dioxide aqueous solution are found to be 0.02 and 0.133 μg g⁻¹, respectively. These values correspond to 5 μg g⁻¹ for Na, 33.25 μg g⁻¹ for Li in original high purity zirconium dioxide powder. The correlation coefficient of calibration curve was 0.995 for Na, 0.985 for Li. Those are comparable to the literature values of detection limits using ICP-OES.     

Quantification of complanatoside A in rat plasma using LC‐MS/MS and its application to a pharmacokinetic study

Complanatoside A is a flavonol glycoside isolated from Astragalus complanatus, and currently it is used as a quality control index for A. complanatus in the 2010 edition of the Chinese Pharmacopoeia. For the first time, a simple and sensitive LC‐MS/MS method was developed for the determination of complanatoside A in rat plasma over the range of 2.3–575 ng/mL. Complanatoside A was extracted from plasma by a protein precipitation procedure, separated by LC and detected by MS/MS in positive electrospray ionization mode. The method was validated for selectivity, carryover, sensitivity, linearity, extraction recovery, matrix effect, accuracy, precision and stability studies. The lower limit of quantification was established at 2.3 ng/mL. Intra‐ and inter‐day precisions (LLOQ, low‐QC, med‐QC and high‐QC) were <7.9%, and accuracies were between 94.0 and 105.1%. Matrix effect was acceptable (97.9–103.0%) and extraction recovery was reproducible (88.5–94.4%). Complanatoside A was stable in the investigated conditions. The method was applied to the pharmacokinetics of complanatoside A in rats. Copyright © 2015 John Wiley & Sons, Ltd.     

LC of sulfonamide residues in poultry muscle and eggs extracts using fluorescence pre‐column derivatization and monolithic silica column

A new, rapid, sensitive and selective HPLC method with fluorescence detection is described for the simultaneous determination of 12 sulfonamides, in the presence of putrescine as internal standard, after pre‐column derivatization with fluorescamine. The drugs were separated on a Chromolith Performance RP‐18 column (100×4.6 mm), using a gradient elution with a binary mobile phase of methanol/0.05 M acetate buffer (pH 3.4). Linearity of derivatization was obtained for concentrations from 3.0 to 300 μg/L in standard solutions. The whole procedure was evaluated and fully validated, according to the European Union Decision 2002/657/EC, for the determination of sulfonamides in turkey muscle and hen eggs following SPE. The LODs varied from 2 to 17 μg/kg in turkey and 2 to 15 μg/kg in egg samples. The average recoveries ranged between 96.9–108.6% in turkey muscle and 96.0–108.4% in egg samples, respectively.     

Separation of trace amounts of Ga and Ge in aqueous solution using nano-particles micro-column

A simple and rapid analytical method for the separation of trace amounts of gallium and germanium from aqueous solution by solid-phase extraction with nano-particles was developed. It was found that only Ga(III) could be quantitatively retained on nano-SiO₂ in the pH range of 3-4 and 8-12 while Ge(IV) was not adsorbed, but both Ga(III) and Ge(IV) ions could be adsorbed quantitatively on nano-TiO₂ within the pH range of 4-11. These two ions adsorbed by nano-particles could be desorbed quantitatively. Effects of acidity, concentration of elution solution and interfering ions on the recovery of the analytes were systematically investigated. The sorption data could be well interpreted by the Langmuir model. Based on the Langmuir model equation, the monolayer adsorption capacity of nano-SiO₂/nano-TiO₂ was calculated to be 4.26 mg g⁻¹/19.68 mg g⁻¹ for Ga(III)/Ge(IV). Moreover, thermodynamic functions, the change of free energy (ΔG⁰), enthalpy (ΔH⁰) and entropy (ΔS⁰) of the adsorption reaction were estimated for each metal ion. Experimental data were also evaluated in terms of kinetic characteristics of adsorption and the adsorption process for both metal ions followed well pseudo-second-order kinetics. Finally, the proposed method was applied to the determination of trace Ga(III) and Ge(IV) in some water samples using loaded nano-particles columns, and it is found that the recoveries of Ga(III) and Ge(IV) were obtained to be in the range of 96.4-105.0%. And the method was validated with certified reference material (GBW07311, GBW 07406) and the values obtained for Ga(III) and Ge(IV) were in good agreement with the certified values.     

Rapid simultaneous determination of codeine and morphine in plasma using LC‐ESI‐MS/MS: Application to a clinical pharmacokinetic study

A rapid and sensitive high‐performance LC‐MS/MS method was developed and validated for the simultaneous quantification of codeine and its metabolite morphine in human plasma using donepezil as an internal standard (IS). Following a single liquid‐liquid extraction with ethyl acetate, the analytes were separated using an isocratic mobile phase on a C₁₈ column and analyzed by MS/MS in the selected reaction monitoring mode using the respective [M+H]⁺ ions, mass‐to‐charge ratio (m/z) 300/165 for codeine, m/z 286/165 for morphine and m/z 380/91 for IS. The method exhibited a linear dynamic range of 0.2–100/0.5–250 ng/mL for codeine/morphine in human plasma, respectively. The lower LOQs were 0.2 and 0.5 ng/mL for codeine and its metabolite morphine using 0.5 mL of human plasma. Acceptable precision and accuracy were obtained for concentrations over the standard curve range. A run time of 2.0 min for each sample made it possible to analyze more than 300 human plasma samples per day. The validated LC‐MS/MS method was applied to a pharmacokinetic study in which healthy Chinese volunteers each received a single oral dose of 30 mg codeine phosphate.     

Determination of trace impurities in high-purity zirconium dioxide by inductively coupled plasma atomic emission spectrometry using microwave-assisted digestion and wavelet transform-based correction procedure

This paper describes a rapid, accurate and precise method for the determination of trace Fe, Hf, Mn, Na, Si and Ti in high-purity zirconium dioxide (ZrO₂) powders by inductively coupled plasma atomic emission spectrometry (ICP-AES). The samples were dissolved by a microwave-assisted digestion system. Four different digestion programs with various reagents were tested. It was found that using a mixture of sulfuric acid (H₂SO₄) and ammonium sulfate ((NH₄)₂SO₄), the total sample dissolution time was 30 min, much shorter than that required for conventional digestion in an opening system. The determination of almost all of the target analytes suffered from spectral interferences, since Zr shows a line-rich atomic emission spectrometry. The wavelet transform (WT), a recently developed mathematical technique was applied to the correction of spectral interference, and more accurate and precise results were obtained, compared with traditional off-peak background correction procedure. Experimental work revealed that a high Zr concentration would result in a significant decrease in peak height of the analyte lines, which was corrected by standard addition method. The performance of the developed method was evaluated by using synthetic samples. The recoveries were in the range of 87-112% and relative standard deviation was within 1.1-3.4%. The detection limits (3σ) for Fe, Hf, Mn, Na, Si and Ti were found to be 1.2, 13.3, 1.0, 4.5, 5.8 and 2.0 μg g⁻¹, respectively. The results showed that with the microwave-assisted digestion and the WT correction, the detection limits have improved by a factor of about 5 for Fe, 4 for Mn and Ti, 3 for Si, and 2 for Hf and Na, respectively, in comparison with conventional open-system digestion and off-peak correction. The proposed technique was applied to the analysis of trace elements above-mentioned in three types of ZrO₂ powders.     

Studies on the influence of esterase inhibitor to the pharmacokinetic profiles of oseltamivir and oseltamivir carboxylate in rats using an improved LC/MS/MS method

Oseltamivir (O), an ethyl ester prodrug of oseltamivir carboxylate (OC), is currently the drug of choice for avian influenza. Previous studies have found that the addition of esterase inhibitor can inhibit the metabolism of O to OC in plasma samples. The current study aims to evaluate the impact of dichlorvos on the rat plasma concentrations of O and OC and subsequent effect on their pharmacokinetics. The plasma samples of rats after oral administration of O were divided into two equal portions for treatment with/without dichlorvos. O and OC plasma concentrations were analyzed by a sensitive and specific LC/MS/MS method, using cephalexin as internal standard for both two analytes. The samples were extracted with an MCX cartridge and separated on a Nova‐Pak CN HP column eluted with a mobile phase of 0.15% formic acid in 50% methanol. The results showed that dichlorvos significantly inhibited further hydrolysis of O to OC during the period of rat plasma sample treatment. A significant difference in the pharmacokinetic parameters of O (except for T_max and t_1/2,λz) was found when the plasma samples were treated with dichlorvos. The use of dichlorvos is recommended in all rat studies which require plasma concentration determination of O and OC. Copyright © 2009 John Wiley & Sons, Ltd.     

Determination of swertianolin in rat plasma by LC‐MS/MS and its application to a pharmacokinetic study

A sensitive and rapid LC‐MS/MS method has been developed and validated for quantifying swertianolin in rat plasma using rutin as an internal standard (IS). Following liquid–liquid extraction with ethyl acetate, chromatographic separation for swertianolin was achieved on a C₁₈ column with a gradient elution using 0.1% formic acid as mobile phase A and acetonitrile as mobile phase B at a flow rate of 0.3 mL/min. The detection was performed on a tandem mass spectrometer using multiple reaction monitoring via an electrospray ionization source and operating in the negative ionization mode. The optimized mass transition ion pairs (m/z) for quantitation were 435.1/272.0 for swertianolin and 609.2/300.1 for IS. The lower limit of quantitation was 0.5 ng/mL within a linear range of 0.5–500 ng/mL. Intra‐day and inter‐day precision was less than 6.8%. The accuracy was in the range of ?13.9 to 12.0%. The mean recovery of swertianolin was >66.7%. The proposed method was successfully applied in evaluating the pharmacokinetics of swertianolin after an oral dose of 50 mg/kg Swertia mussotii extract in rats. Copyright © 2014 John Wiley & Sons, Ltd.     

Evaluation of a new modified QuEChERS method for the monitoring of carbamate residues in high‐fat cheeses by using UHPLC–MS/MS

A simple and efficient method for the determination of 28 carbamates in high‐fat cheeses is proposed. The methodology is based on a modified quick, easy, cheap, effective, rugged, and safe procedure as sample treatment using a new sorbent (Z‐Sep⁺) followed by ultra‐high performance liquid chromatography with tandem mass spectrometry determination. The method has been validated in different kinds of cheese (Gorgonzola, Roquefort, and Camembert), achieving recoveries of 70–115%, relative standard deviations lower than 13% and limits of quantification lower than 5.4 μg/kg, below the maximum residue levels tolerated for these compounds by the European legislation. The matrix effect was lower than ±30% for all the studied pesticides. The combination of ultra‐high performance liquid chromatography and tandem mass spectrometry with this modified quick, easy, cheap, effective, rugged, and safe procedure using Z‐Sep⁺ allowed a high sample throughput and an efficient cleaning of extracts for the control of these residues in cheeses with a high fat content.     

Quantitative determination of euphol in rat plasma by LC‐MS/MS and its application to a pharmacokinetic study

Euphol is a potential pharmacologically active ingredient isolated from Euphorbia kansui. A simple, rapid, and sensitive method to determine euphol in rat plasma was developed based on liquid chromatography‐tandem mass spectrometry (LC‐MS/MS) for the first time. The analyte and internal standard (IS), oleanic acid, were extracted from plasma with methanol and chromatographied on a C₁₈ short column eluted with a mobile phase of methanol–water–formic acid (95:5:0.1, v/v/v). Detection was performed by positive ion atmospheric pressure chemical ionization in selective reaction monitoring mode. This method monitored the transitions m/z 409.0 → 109.2 and m/z 439.4 → 203.2 for euphol and IS, respectively. The assay was linear over the concentration range 27–9000 ng/mL, with a limit of quantitation of 27 ng/mL. The accuracy was between –7.04 and 4.11%, and the precision was <10.83%. This LC‐MS/MS method was successfully applied to investigate the pharmacokinetic study of euphol in rats after intravenous (6 mg/kg) and oral (48 mg/kg) administration. Results showed that the absolute bioavailability of euphol was approximately 46.01%. Copyright © 2014 John Wiley & Sons, Ltd.     

Analysis and tentative structure elucidation of new anthocyanins in fruit peel of Vitis coignetiae Pulliat (meoru) using LC‐MS/MS: Contribution to the overall antioxidant activity

The skin of Vitis coignetiae Pulliat (meoru) grown wild in the Republic of Korea was analyzed for anthocyanins via HPLC coupled to ESI‐MS/MS in positive ion mode. Chromatographic separation was conducted via RP HPLC using a C₁₈ column, with a 50‐min gradient from 0 to 80% methanol in water containing 0.5% formic acid. A total of 18 anthocyanins were identified. Among them, nine compounds were newly determined by comparing the retention time (t_R) and mass fragmentation patterns with those of the previously reported anthocyanins for other grape varieties: malvidin hexose, peonidin 3‐galactoside, malvidin 3‐galactoside, cyanidin, petunidin, petunidin 3‐(6″‐coumaroyl)‐5‐diglucoside, peonidin, malvidin, and malvidin 3‐(6″‐coumaroyl)‐5‐diglucoside. The antioxidant activity of the V. coignetiae Pulliat anthocyanins was determined via 2,2‐diphenyl‐2‐picrylhydrazyl radical scavenging and 2,2′‐azinobis‐(3‐ethylbenzothiazoline‐6‐sulfonic acid) radical cation assays in a range of concentration from 25 to 500 mg/L. The capacity increased with concentration. The IC₅₀ values, defined as the concentration of sample required to scavenge 50% of free radicals, were calculated as follows: 189.63±11.31 mg/L and 141.29±6.70 mg/L for 2,2‐diphenyl‐2‐picrylhydrazyl and 2,2′‐azinobis‐(3‐ethylbenzothiazoline‐6‐sulfonic acid) radical cation, respectively. The antioxidant activity of the V. coignetiae Pulliat anthocyanins is substantially higher than that of ascorbic acid and is similar to the effects of the extracts obtained from other grape varieties.     

Separation and preconcentration of trace amounts of aluminum ions in surface water samples using different analytical techniques

A separation/preconcentration of aluminum (III) (Al³⁺) has been developed to overcome the problem of high matrix species, which may interfere with the determination of trace quantity of Al³⁺ in natural water samples. The separation of Al³⁺ in water samples was carried out from interfering cations by complexing them with 2-methyle 8-hyroxyquinoline (quinaldine) on activated silica. Whereas the separated trace amounts of Al³⁺ was preconcentrated by cloud point extraction (CPE), as prior step to its determination by spectrofluorimetry (SPF) and flame atomic absorption spectrometry (FAAS). The Al³⁺ react with 8-hydroxyquinoline (oxine) and then entrapped in non-ionic surfactant Triton X-114. The main factors affecting CPE efficiency, such as pH of sample solution, concentration of oxine and Triton X-114, equilibration temperature and time period for shaking were investigated in detail. The validity of separation/preconcentration of Al³⁺ was checked by certified reference material of water (SRM-1643e). After optimization of the complexation and extraction conditions, a preconcentration factor of 20 was obtained for Al³⁺ in 10 mL of natural water samples. The relative standard deviation for 6 replicates containing 100 μg L⁻¹ of Al³⁺ was 5.41 and 4.53% for SPF and FAAS, respectively. The proposed method has been applied for determination of trace amount of Al³⁺ in natural water samples with satisfactory results.