Determination Of Inorganic Anions Research Articles

Determination of inorganic anions in uranium ore concentrate reference materials

The determination of inorganic anions in uranium ore concentrates (UOCs) is useful to nuclear forensics for establishing the provenance of sample materials. In this collaborative study, quantitation of inorganic anions was carried out on three UOC reference materials from the National Research Council Canada: UCLO-1 (https://doi.org/10.4224/crm.2020.uclo-1), UCHI-1 (https://doi.org/10.4224/crm.2020.uchi-1), and UPER-1 (https://doi.org/10.4224/crm.2020.uper-1). The analytes were extracted into water and characterized by ion chromatography with combined standard uncertainties (uc) between 1.6 and 11%. The highest contributor to uc was homogeneity. Sulfate was the most abundant anion (2000–12,000 mg/kg SO42−). Other anions were in the 15–500 mg/kg range.

Determination of inorganic anions in the whole blood by ion chromatography

A fast, precise, and accurate method that can simultaneously determine 7 anions in whole blood was established by on line dialysis-double suppression ion chromatography. Performance parameters which could affect the determination of anions were optimized, including the selection of protein precipitant in samples, the amount of filtrate discarded, selection of eluent flow rate, influence of the Ag-Na column on experimental results, influence of ethylenediamines on ClO2−, and investigation of nitrogen drying. Finally, 3.6 mmol/L sodium carbonate was selected as eluent, with a flow rate of 0.8 mL/min, to separate the 7 anions. Blood and alcohol (v/v, 1:4) were used to precipitate the proteins in blood. The 7 anions reached an adequate recovery rate when the first 2 mL of filtrate from the C18 column was discarded. The recovery rate at LLOQ, low, medium, and high concentrations was 80–120%. The correlation coefficients (r2) of the calibration curves of the targeted anions ranged from 0.9975 to 0.9998. The limit of detection (LOD) was 0.309–7.71 μg/L. This method has simple pretreatment, high accuracy, and good reproducibility and selectivity, and is suitable for the separation and determination of anions in blood.

イオンクロマトグラフィーによる海水中の無機陰イオンの定量─逆相系C18シリカカラムにおける残存シラノール基の効果─

イオンクロマトグラフィー（IC）による，海水中に存在する6種無機陰イオン［ヨウ素酸イオン（IO3−），臭素酸イオン（BrO3−），臭化物イオン（Br−），亜硝酸イオン（NO2−），硝酸イオン（NO3−），ヨウ化物イオン（I−）］の一斉定量を検討した．分離カラムとして残存シラノール基を持つ逆相系C18シリカカラムを用いた．溶離液に0.3 M塩化ナトリウム＋0.5 mM塩化ドデシルアンモニウム（DAC）＋5 mMリン酸緩衝液（pH 4.5）（流量1 mL min−1），検出器にUV検出器（225 nm）を用いたところ，19分以内で目的イオンの測定が可能であった．残存シラノール基を持つ逆相系C18シリカカラム（エンドキャップ未処理カラム）はエンドキャップ処理カラムと比べてBr−とNO2−間の分離が良好であった．繰り返し精度は保持時間，ピーク面積，ピーク高さの相対標準偏差（RSD（％））が1.55％ 以内（n＝5）であり，24時間の連続測定では2.97％ 以内（n＝48）であった．検量線は良好な直線性（r2>0.999）を示した．検出限界値（S/N＝3）は，IO3−（8.3 μg L−1），BrO3−（24 μg L−1），Br−（92 μg L−1），NO2−（0.8 μg L−1），NO3−（3.2 μg L−1），I−（1.0 μg L−1）であった．瀬戸内海水の標準添加による回収率は93～108％ であった．本法を瀬戸内海（広島湾）5地点で夏季の海水中陰イオン濃度の深度依存性に適用した．溶離液の流量1.5 mL min−1では対象イオンの分離・検出に問題はなく1サンプルの測定時間は13分であった．

Determination of inorganic anions and organic acids in water, beverages and orange juice by capillary electrophoresis

Determination of inorganic anions and organic acids in water, beverages and orange juice by capillary electrophoresis

Determination of Inorganic Anions in Seawater Samples by Ion Chromatography with Ultraviolet Detection Using Monolithic Octadecylsilyl Columns Coated with Dodecylammonium Cation.

A fast and sensitive ion chromatographic method for the simultaneous determinations of six inorganic anions [iodate (IO3-), bromate (BrO3-), bromide (Br-), nitrite (NO2-), nitrate (NO3-), and iodide (I-)] in seawater is described using dodecylammonium (DA+)-coated monolithic octadecylsilyl (ODS) columns, a concentrated aqueous NaCl mobile phase containing dodecylammonium chloride (DAC), and a UV detector. The DA+-coated monolithic ODS columns show greater retention for iodate and weaker retention for iodide, compared to dilauryldimethylammonium (DDA+)-coated monolithic ODS columns. Six anions were determined within 12 min with baseline separation without interferences by matrix ions, such as Cl- and SO42-, in seawater, compared to a DA+-coated particulate ODS column (it took 25 min per sample) obtained previously. The detection limits (DLs) were comparable to the DA+-coated particulate ODS column: IO3- (7.7 μg L-1), BrO3- (20), Br- (88), NO2- (0.9), NO3- (1.9), and I- (0.9) with a 100-μL sample injection. A larger sample volume injection lowered the DLs of IO3-, BrO3-, and I-. The good performance was maintained for ca. 2 years examined. The robust IC system developed in the present work was successfully applied to real seawater samples without sample dilution in the recovery rates of 93 - 104% for all ions.

Determination of inorganic anions and organic acids in beer by replacement-ion chromatography with ultraviolet detection

Determination of inorganic anions and organic acids in beer by replacement-ion chromatography with ultraviolet detection

Jednoczesne oznaczanie nieorganicznych anionów oraz kwasów karboksylowych metodą chromatografii jonowej z elucją gradientową

Jednoczesne oznaczanie nieorganicznych anionów oraz kwasów karboksylowych metodą chromatografii jonowej z elucją gradientową

Simultaneous determination of inorganic anions in bottled drinking water by the ion chromatography method

Simultaneous analysis of seven inorganic anions (fluoride, chloride, nitrite, bromide, nitrate, phosphate and sulfate-ions) was carried out in two sets of 10 brands of mineral bottled waters (Iran) using ion chromatography (IC). Waters were sampled in autumn and winter of 2010. The obtained concentrations compared with the values on the labels. It was established that concentrations of the specified ions in tested waters were within the acceptable levels of the World Health Organization (WHO) and the United States Environmental Protection Agency (USEPA). Comparison of label values with our experiments showed that 11 label values had meaningful difference from the corresponding test values. The analysis of variance (ANOVA) revealed that sampling in autumn and winter periods did not influence the content of ions in water.

Validation of atmospheric aerosols parallel sampling in a multifold device

In this work, particulate matter was collected using an active sampling system consisting of a PM10 (<10 μm) inlet coupled to a multifold device containing six channels, connected to a vacuum pump. Each channel was equipped with a filter holder fitted with adequately chosen filters. The system was fixed on a metallic structure, which was placed on the roof of the laboratory building, at the Faculty of Sciences, in Lisbon. Sampling took place under flow-controlled conditions. Aerosols were extracted from the filters with water, in defined conditions, and the water-soluble fraction was quantified by ion chromatography (IC) for the determination of inorganic anions (Cl(-), NO3 (-) and SO4 (2-)). Equivalent sampling through the various channels was validated. Validation was based on the metrological compatibility of the content results for the various filters. Ion masses are metrologically equivalent when their absolute difference is smaller than the respective expanded uncertainty. When this condition is verified, the studied multifold device produces equivalent samples.

Flow through Fluorescence Detection of Phosphate in Human Saliva Based on Sensitized Turn-On Photoluminescence of CdS Quantum Dots

ABSTRACTThe development of fluorescent turn-on probes for the determination of inorganic anions based on fluorescent semiconductor nanocrystals (quantum dots) has recently attracted great attention. Methods reported so far enable anion sensing at elevated concentration levels and usually with low selectivity against other abundant matrix components. In this work, we describe an alternative approach that combines the appropriate modulation of nanocrystal surface chemistry (i.e., stabilization) with rational design and modulation of the experimental conditions (i.e., flow injection analysis) in order to deliver an expedient flow through method that enables the determination of phosphate at low concentration levels and with good selectivity. The developed method was successfully applied to the determination of phosphate in artificial and human saliva with good analytical features in terms of reproducibility and repeatability (2.3–9.2%), recoveries from fortified samples (96.0–112.0%), linearity of response curves to phosphate concentrations (R2 > 0.99), and satisfactory sensitivity (<1 µM), providing a significant improvement to previous fluorescent turn-on quantum dot probes.

Determination of inorganic anions and gluconate by two-dimensional ion chromatography

A new two-dimensional ion chromatography method was developed to parallelly analyze two different types of samples with the application of valve switching technology-suppressed conductivity and pulsed amperometric analysis system, for concurrent determination of chloride, nitrite, sulfate, nitrate four inorganic anions and gluconate. The first dimensional chromatography was using Ionpac AG18+Ionpac AS18 anion analysis columns with a suppressed conductivity detector for the separation and detection of Cl-, NO2-, SO4(2-) and NO3-. Respectively, the elution was 5 and 20 mmol/L NaOH at an isocratic flow rate of 1.0 mL/min and sample injection volume of 25 μL. The second dimensional chromatography was utilizing two guard columns, CarboPac PA1 and CarboPac PA20, with 90 mmol/L NaOH solution for the isocratic eluent of 0.8 mL/min. Gluconate was enriched by an AG15 column and switched into the pulsed amperometric detector. The results showed that: each inorganic anion in 0. 1-5.0 mg/L and gluconate in 0.085 6-4.282 5 mg/L had a good linear relationship (R2 ≥ 0.994 5). The RSDs of the peak areas were between 1.05%-1.94%. The limits of detection were 0.61-2.17 μg/L for the anions and 24.24 μg/L for the gluconate. The recoveries were between 90.3% - 102.8%. The two detection modes parallelly have good separation efficiency, detection accuracy and the precision of the separation and are suitable for the analysis of complex samples.

Determination of inorganic anions in oilfield water using capillary electrophoresis with indirect fluorescence detection

Analysis of high salinity oilfield water presents challenges. Here we develop a method for determination of bromide, chloride, nitrate and sulfate using 8-hydroxypyrene trisulfonic acid as an indirect fluorescence probe.

ドデシルアンモニウム陽イオン吸着―逆相系C18カラムを用いた陰イオンクロマトグラフィーと海水中の微量陰イオンの同時定量

ドデシルアンモニウム陽イオン吸着―逆相系C18カラムを用いた陰イオンクロマトグラフィーと海水中の微量陰イオンの同時定量

Determination of inorganic anions in saliva by electroosmotic flow controlled counterflow isotachophoretic stacking under field-amplified sample injection

Under a strong counter-electroosmotic flow, five salivary inorganic anions, bromide, iodide, nitrite, nitrate and thiocyanate were determined by field-amplified sample injection in combination with isotachophoretic stacking. Separation and concentration conditions were investigated. A terminating electrolyte, 5mM borate, was added in the sample. Under the optimized conditions, Br(-), I(-) and SCN(-) were concentrated online using 150mM HCl-Tris buffer at pH 7.8 in a bare fused capillary, providing more than ten thousand of sensitivity enrichment compared with normal injections. The relative standard deviations (RSDs, n=5) were less than 1% in migration times, 8% in peak areas. Using direct UV detection at 200nm and 226nm, the limits of detection (LODs, S/N=3) were of 0.002-0.01μM. Unfortunately, NO2(-) and NO3(-) could be observed in purified or deionized water. Therefore, a low dilution factor was applied to saliva samples. Due to the matrix effect, samples were injected in a shorter time, and standard addition method was applied to determine all the five inorganic anions in saliva. The RSDs of the migration times and peak areas were in a range of 0.2-0.4% and 3.0-4.0%, respectively. The LODs were 0.2-2.0μM. The salivary levels of the anions obtained were in accord with the reference data. The external standard method can not be adapted to real samples due to biases caused by electrokinetic injection and errors from high dilutions.

Poly(ethylene oxide)-bonded stationary phase for separation of inorganic anions in capillary ion chromatography

A tosylated-poly(ethylene oxide) (PEO) reagent was reacted with primary amino groups of an aminopropylsilica packing material (TSKgel NH2-60) in acetonitrile to form PEO-bonded stationary phase. The reaction was a single and simple step reaction. The prepared stationary phase was able to separate inorganic anions. The retention behavior of six common inorganic anions on the prepared stationary phase was examined under various eluent conditions in order to clarify its separation/retention mechanism. The elution order of the tested anions was iodate, bromate, bromide, nitrate, iodide, and thiocyanate, which was similar as observed in common ion chromatography. The retention of inorganic anions could be manipulated by ion exchange interaction which is expected that the eluent cation is coordinated among the PEO chains and it works as the anion-exchange site. Cations and anions of the eluent therefore affected the retention of sample anions. We demonstrated that the retention of the analyte anions decreased with increasing eluent concentration. The repeatability of retention time for the six anions was satisfactory on this column with relative standard deviation values from 1.1 to 4.3% when 10mM sodium chloride was used as the eluent. Compared with the unmodified TSKgel NH2-60, the prepared stationary phase retained inorganic anions more strongly and the selectivity was also improved. The present stationary phase was applied for the determination of inorganic anions contained in various water samples.

Matrix Influences on the Determination of Common Ions by using Ion Chromatography Part 1--Determination of Inorganic Anions

Ion chromatography is the most popular instrumental analytical method used for the determination of anions and cations in water and wastewater. Isocratic ion chromatography with suppressed conductivity detection is frequently used in laboratories carrying out routine analyses of inorganic anions. The paper presents the results of the research into the influence of selected inorganic anions dominant in environmental samples (Cl(-), NO(3)(-), SO(4)(2-)) on the possibility of simultaneous determination of F(-), Cl(-), NO(2)(-), NO(3)(-), PO(4)(3-) and SO(4)(2-) with the application of this most popular ion chromatography type in standard separation conditions. Four Dionex and four Metrohm anion-exchange columns were tested in standard separation conditions recommended by their manufacturers with both standard solutions and environmental samples with complex matrix.

Determination of Inorganic Anions by Capillary Ion-exchange Chromatography Using Polyethylenimine-coated Octadecyl-bonded Phases

The utility of a cationic polymer polyethylenimines (PEI) for coating some commercially available silica-based stationary phases packed in capillaries of 0.32 mm i.d. and 10 cm long was studied for the separation and direct UV detection of inorganic anions (iodate, bromate, nitrite, bromide, and nitrate ions). With a super-endcapped octadecylated silica stationary phase, which yielded the best separation in terms of resolution and retention time of individual anions, the effect of the pH and composition of the eluent on the elution behavior of individual anions was studied. The relative standard deviations of the retention time, peak area and peak height for 60 successive injections (running time of more than 10 h) were not more than 1.32, 2.30 and 1.94, respectively, with the exceptions of the peak area and peak height of the bromate ion. The detection limits at 210 nm ranged from 1 to 7 ppm. This method was successfully applied to determine concentrations of nitrate ions present in pills and beverage samples.

Determination of Inorganic Anions in Ethyl Acetate by Ion Chromatography with an Electromembrane Extraction Method

In this work, the determination of inorganic anions in slightly water-soluble organic solvents (ethyl acetate) was realized by ion chromatography (IC) with a novel-efficient electromembrane extraction method. From an 8 mL ethyl acetate sample, three inorganic anions migrated through the pores of a polypropylene hollow fiber membrane, and into deionized water inside the lumen of the hollow fiber by the application of 600 V. The transport was forced by an electrical potential difference sustained over the liquid membrane, resulting in electrokinetic migration of inorganic anions from the donor compartment to the acceptor solution. After the electromembrane extraction, the acceptor solution was analyzed by IC with a sodium carbonate-sodium bicarbonate eluent. The applied voltage, stirring speed, and extraction time for controlling the extraction efficiency were optimized. Within 10 min of operation at 600 V, chloride, bromide, and sulfate were extracted with recoveries in the range 76-110%, which corresponded to a linear range of 0.01-1 mg/L. The procedure was applied to the analysis of inorganic anions in a real ethyl acetate sample and expands onto other slightly water-soluble organic solvents.

Determination of Inorganic Anions by Capillary IC Using Hexadimethrine Bromide-Modified Silica Stationary Phases

A simple, rapid and highly sensitive capillary ion chromatographic method for direct determination of iodide and thiocyanate is reported. Separation was achieved on a laboratory-made capillary column (100 mm × 0.32 mm i.d.) packed with silica gel, followed by modification with 20 mM hexadimethrine bromide. Sodium perchlorate–methanol (95:5, v/v) was used as the eluent and analyte anions were detected at 225 nm. Iodate, bromate, nitrate, iodide and thiocyanate were eluted within 8 min, with relative standard deviations of the retention time, peak area and peak height smaller than 2.4%. Effects of the eluent composition on the retention behavior were also investigated. The limit of detection (S/N = 3) of iodide was 6.5 μg L−1, whereas that of thiocyanate was 16.2 μg L−1. The method was successfully applied to the rapid and direct determination of iodide in powdered milk and thiocyanate in human saliva without any pre-concentration. The modified column could be used for about 1 month (8 h operation per day) without loss of hexadimethrine bromide.

Identification and determination of inorganic anions in real extracts from pre- and post-blast residues by capillary electrophoresis

Fast, selective, and sensitive analysis of inorganic anions is compulsory for the identification of explosives in post-blast or environmental samples. For the last twenty years, capillary electrophoresis (CE) has become a valuable alternative to ion chromatography (IC) for the analysis of inorganic-based explosives because of its low running costs and its simplicity of use. This article focuses on the development and validation of a CE method for the simultaneous analysis of 10 anions (chloride, nitrite, nitrate, thiosulphate, perchlorate, chlorate, thiocyanate, carbonate, sulphate, and phosphate) which can be found in post-blast residues, plus for the first time azide anion, possibly present in the composition of detonators, and the internal standard (formate) in 20 min total runtime. Intermediate precisions were 2.11% for normalized areas and 0.72% for normalized migration times. Limits of detection close to 0.5 ppm for all anions were obtained with the use of preconcentration techniques, thanks to a fast and simple sample preparation allowing the analysis of a large variety of matrices with the developed generic CE method. The matrix effects were statistically studied for the first time in the explosive field for different matrices, containing interfering anions and cations, sometimes at high levels. In fact, no significant matrix effect occurred (tests with blank matrix extracts of soil, cloth, glass, plastic, paper, cotton, and metal). Finally, analyses of real post-blast residues and real detonator extracts were performed. The CE results were compared with those obtained with the IC method used routinely and showed excellent correlation.