离子色谱法测定酒中叠氮根离子

建立了一种测定酒中叠氮化物的离子色谱方法(IC)。样品经稀释、过滤后,依次过OnGuard RP柱和OnGuard Na柱以除去疏水性物质和重金属离子的干扰。以KOH梯度淋洗,淋洗液流速为1.0 mL/min,采用DionexIonPacAS18色谱柱分离,IonPac TAC-UPL1预浓缩富集进样,最后用DS6电导检测器检测,外标法定量。N3-的线性范围为0.005~0.5μg/mL,线性相关系数为0.9998,加标回收率为88%~106%,检出限为0.002μg/mL(以信噪比S/N=3计),相对标准偏差为0.1%~0.6%。     

离子色谱法检测阿莫西林钠中二乙胺和三乙胺

建立了检测阿莫西林钠原料药中二乙胺、三乙胺的离子色谱法.色谱柱为Dionex CS17 (250×4mm),流动相为6mmol·L-1甲磺酸,流速为1.0mL·min-1,进样量为25μL,柱温为35℃,检测方式为抑制电导检测.结果表明:二乙胺和三乙胺的质量浓度线性范围分别为0.015 ～ 19.85μg·mL-1(r...     

毛细管离子色谱法测定酒和饮料中阳离子

建立了毛细管离子色谱测定酒、饮料等样品中阳离子的分析方法。使用毛细管离子色谱柱IonPac CS12A(250 mm×0.4 mm, 8 μm),以甲基磺酸淋洗液发生器(EGC-MSA)产生18 mmol/L的甲基磺酸为流动相,进样量0.4 μL,在流速0.01 mL/min的条件下,采用自循环抑制电导检测的方法对啤酒、葡萄酒、白酒、果汁及奶茶等样品中的阳离子含量进行检测。结果表明,毛细管离子色谱法能满足阳离子含量的测定要求,系统稳定不易堵,在灵敏度方面优于常规离子色谱系统。该方法能够快速、准确地测定酒、饮料等样品中的5种阳离子(钠、铵、钾、镁和钙),回归方程的相关系数在0.9997以上,实际样品的加标回收率为95.2%～103.3%。该方法具有灵敏度高,操作简单,环境友好的特点。     

Determination of sodium and ammonium ions in disproportionate concentration ratios by ion chromatography

In ion chromatography, samples of very different ammonium-to-sodium concentration ratios are difficult to quantify since these two cations have similar selectivities for stationary phases containing commonly used sulfonate or carboxylate cation-exchange functional groups. The IonPac CS15 cation-exchange column, with carboxylate and phosphonate functional groups as well as a crown ether group, was developed to address this limitation. Selectivity for the common inorganic cations on this column is different from that of conventional cation-exchange columns in that the separation between sodium and ammonium ions has been greatly increased, allowing for determinations of low levels of one in the presence of high levels of the other with an isocratic eluent. For larger than 4000:1 sodium-to-ammonium concentration ratios, an eluent step change or gradient elution is needed. For moderate ratios, combinations of this column with a carboxylate column, containing no crown ether group, can be used at room temperature with an isocratic eluent containing no organic solvent.     

Determination of microgram amounts of azide by gas chromatography

Azide ions (5–120 μg) are oxidized by cerium(IV) in an acidic medium. The nitrogen evolved is displaced by helium carrier and quantified by gas chromatography with a thermal conductivity detector. The relative standard deviation is <5%. Many sulphur anions, cyanide and some metal ions which form azide complexes do not interfere.     

阀切换-离子色谱法测定分析纯硫酸钠中痕量氯离子

建立了阀切换-离子色谱法测定分析纯硫酸钠固体中痕量氯离子含量的方法。ICS-2100离子色谱系统,配置十通阀,用IonPac AS18色谱柱将硫酸钠固体样品中的氯离子和硫酸根离子预分离后,以IonPac TAC-ULP1为富集柱,将氯离子富集后在相同的IonPac AS18色谱柱上进行定量分析。同时以淋洗液发生器产生的不同浓度的KOH作为淋洗液,以抑制型电导检测器测定氯离子的含量。结果表明,阀切换-离子色谱法测定分析纯硫酸钠固体中的痕量氯离子,检出限为10 μg/L,线性相关系数(r2)大于0.999,实际样品的加标回收率为98.0%～103.0%,具有分离度和灵敏度高,选择性好,操作简单等特点。该方法能够准确测定硫酸钠固体中痕量氯离子的含量,适用于高纯化学试剂中痕量氯离子的分离测定。     

Determination of glyphosate by ion chromatography

An ion chromatography system for the determination of glyphosate was described. Ion chromatograph was carried out by suppressed conductivity detection (DX-100). The eluent contained 9 mmol l⁻¹ Na₂CO₃ and 4 mmol l⁻¹ NaOH. The detection limit was 0.042 μg ml⁻¹ (S/N=3). The relative standard deviation was 1.99% and the correlation coefficient of the calibration curve for area was 0.9995. The linear range was 0.042100 μg ml⁻¹. Common inorganic ion and organic acids did not interfere. The recovery was 96.4103.2%. The method was simple, rapid, reliable and inexpensive.     

Determination of organic anions in waste liquid of sodium hydrosulfite production by ion chromatography.

An ion chromatographic method for simultaneous determination of formate, hydroxyethyl sulfonate (HES), hydroxyethyl thiosulfate (HET), and coexisting anions in the industrial waste liquid of sodium hydrosulfite production was developed. The mixture of 1.6 mmol/l of phthalic acid and 1.2 mmol/l tri-(hydroxyethyl) aminomethane was used as eluent. The interference of coexisting sulfite anion with HES was avoided by selective oxidation with hydrogen peroxide as oxidizer. The other coexisting inorganic anions, Cl-, SO4(2-) and S2O3(2-) can be determined simultaneously. The linear range of the peak area calibration curves for all analytes was up to two or three orders of magnitude. The detection limits (S/N = 3) for formate, HES and HET were 2.4, 1.0 and 0.5 mg/l, respectively. The recoveries for all analytes were 91.61-100.6%.     

离子色谱法测定“地沟油”中钠离子和氯离子的含量及其比例关系

采用离子色谱法测定“地沟油”样品中钠离子和氯离子的含量,通过计算两者的比例关系确定样品中是否含有“地沟油”。使用去离子水提取“地沟油”样品中钠离子和氯离子。氯离子以20 nmol/L KOH溶液为淋洗液,AS19分离柱(250 mm×4 mm)分离,抑制器电流112 mA;钠离子以20 nmol/L甲基磺酸(MSA)为淋洗液,CS12分离柱(250 mm×4 mm)分离,抑制器电流59 mA;两者分离采用的其他相同色谱条件为: 柱温、检测器温度30 ℃,电导检测器检测,进样量25 μL,流量1 mL/min,峰面积定量。氯离子的检出限为0.005 mg/L,在0～5 mg/L范围内有良好的线性关系（r2=0.999988）;钠离子的检出限为0.001 mg/L,在0～5 mg/L范围内有良好的线性关系（r2=0.999926）。氯离子平均加标回收率为94.2%,相对标准偏差(RSD)为2.4%;钠离子平均加标回收率为92.5%, RSD为2.7%。经测定、计算,正常食用油中钠离子和氯离子的物质的量比约为1,而“地沟油”中钠离子与氯离子的物质的量比高于4。“地沟油”中钠离子和氯离子的含量及其比例关系可作为判断“地沟油”的重要依据。     

Determination of sodium,potassium, calcium and magnesium cations in biodiesel by ion chromatography

This work reports an ion chromatographic (IC) method for the quantitative determination of inorganic cations (Na⁺, K⁺, Mg²⁺ and Ca²⁺) in biodiesel samples that were synthesized from different vegetable oils and fat. The proposed method uses water extraction, heating and ultrasound. The limits of detection (LOD) for each ion, in milligrams of the analyte per kilogram of biodiesel (mg kg⁻¹), were respectively: 0.11 (Na⁺); 0.42 (K⁺); 0.23 (Ca²⁺); and 0.36 (Mg²⁺). The accuracy of the method was studied through recovery tests. For comparison, two samples were also analyzed using an Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) procedure. The paired Student t test and the Snedecor F test showed that both methods offer equivalent results in terms of accuracy and precision. The operational simplicity, accuracy and precision of the proposed method suggest that it can be a good alternative for the determination of inorganic cations in biodiesel samples.     

Determination of biogenic amines in alcoholic beverages by ion chromatography with suppressed conductivity detection and integrated pulsed amperometric detection

The determination of biogenic amines in alcoholic beverages is important to assess the potential risks associated with the consumption of high concentrations of these compounds. In addition, product storage conditions and the length of storage can cause the formation of biogenic amines that reduce product quality. We report a new method using cation-exchange chromatography with either suppressed conductivity, integrated pulsed amperometry, UV, or a combination of these detection techniques to determine biogenic amines in alcoholic beverages. The main objective was to provide a direct comparison between IPAD and suppressed conductivity detection for determining biogenic amines in alcoholic beverages. Suppressed conductivity is the simplest detection approach for determining putrescine, cadaverine, histamine, agmatine, phenylethylamine, spermidine, and spermine with good sensitivity (0.004-0.08 mg/l) and was used to evaluate the influence of storage time and conditions on the evolution of biogenic amines in alcoholic beverages. Integrated pulsed amperometric detection (IPAD) detects more biogenic amines than suppressed conductivity detection, enabling the detection of dopamine, tyramine, and serotonin. Tyramine was simultaneously determined by UV detection and IPAD to provide confirmation and ensure the accuracy of the analytical results. The linearity of biogenic amine responses was within 0.1-20 mg/l and peak area precisions were 0.24-4.97% for IPAD, suppressed conductivity-IPAD, and UV detection. The sensitivity for the 10 biogenic amines using the 3 detection techniques varied considerably from 0.004-1.1 mg/l and recoveries were within 85-122%.     

Determination of lithium in wines by ion chromatography

Lithium ion can be added as a denaturing agent to wines unsuitable for consumption. Accuracy of flame atomic emission spectroscopy with direct nebulization, which is commonly adopted for discovering illegal use of denatured wines, was found to be compromised by Na+, K+, NH4+, Mg2+, Ca2+ and ethanol contained in wine. Ion chromatography (IC) was tested in order to propose an alternative method for legal controls. Experimental design was used to investigate the influence on the accuracy of the determination of Li+ at ppb levels, of Na+ and ethanol content of wine and of fluctuations of eluent flow-rate and composition. It turned out that IC quantification of Li+ can be affected by eluent parameters rather than by wine composition. Since the former can be maintained under the operators control, while the latter cannot, IC was judged preferable to AES for legal controls of Li+ in wines.     

食品中亚硫酸盐的离子色谱法测定

建立了食品中亚硫酸盐的离子色谱检测方法. 样品采用40 mmol/L NaOH溶液提取, 甲醛作稳定剂, 经ENVI-Carb活性碳小柱除去提取液中的色素, 石油醚除去提取液中的油脂, 用配有电导检测器的离子色谱仪测定. 以AS9-HC为色谱柱, 流动相为8 mmol/L Na2CO3-2.5 mmol/L NaOH, 亚硫酸盐的残留量在0～6.0 mg/L的范围内线性关系良好, 相关系数为0.9989, 相对标准偏差为1.3%～9.1%, 回收率在88.4%～98.1%之间.     

离子色谱法测定土壤中植物激素乙烯利

土壤样品中的乙烯利在IonPac AS14分离柱（4mm）,（3．5mmol Na2CO3＋1．0mmol NaHCO3）／L淋洗液的淋洗条件下得到较好的分离。在0～10μg／mL的范围内标准曲线呈线性,检出限为（0．08μg／mL）。精密度好,10．266μg／mL时,保留时间的RSD=0．86％;峰高的RSD=1．1％;峰面积的RSD=1．0％。在此条件下,其它阴离子对乙烯利的检测不干扰,样品的加标回收率为85．6％～87．9％。     

离子色谱法测定葡萄酒中的高氯酸盐

建立了离子色谱测定红酒中高氯酸盐的分析方法。以4种葡萄酒为典型样品,测定了其中的高氯酸盐含量。使用Metrosep A Supp5阴离子分析柱（150 mm×4.0 mm）进行分离,柱温为40℃,流动相为1.0 mmol/L碳酸钠水溶液-丙酮（85：15,v/v）,流速为0.8 mL/min。结果表明,高氯酸盐在0.1~10 mg/L内具有良好的线性关系,相关系数为0.9998,方法回收率大于86.0%,相对标准偏差小于2.6%。该方法前处理方便快捷、检测灵敏度高,可满足红酒中高氯酸盐含量的测定。     

Determination of moniliformin in maize by ion chromatography

An ion chromatographic method for the determination of the mycotoxin moniliformin in maize was developed. The method contains a fast and simple clean-up procedure, which allows high volume sample injection. No further pre-concentration step is required. The limit of quantification was estimated to be 0.12 mg/kg moniliformin in maize. In contrast to the two previously published ion chromatographic methods, the moniliformin peak is base line separated and occurs in a region of a smooth base line in the ion chromatogram. The newly developed method showed a recovery through the whole analytical procedure of 97+/-3.5 %, whereas most previously described analytical methods had recoveries in the 70% range.     

离子色谱法检测盐酸头孢吡肟中的N-甲基吡咯烷

建立了一种盐酸头孢吡肟中的N-甲基吡咯烷的离子色谱分析方法.采用阳离子交换柱IonPac CS12A作分析柱,甲烷磺酸-乙腈为淋洗液,外加水电抑制模式,电导检测,在10 min内即可完成分析.线性良好(r2=0.9985),样品的RSD在5%以下(n=6),回收率在89.5%～108.4%之间.方法可在盐酸头孢吡肟产品的检验中发挥作用.     

Determination of ammonium in seawater by column-switching ion chromatography

A system which combines column switching and concentration was developed. A binary eluent mechanism was developed to study the effect of high sample concentration matrix on retention time shifts of the trace analyte. Separation conditions were chosen according to this mechanism to reduce the retention time shift of ammonium in the presence of high concentration sodium ion: high concentration sulfuric acid (25 mmol/l) was used as the eluent, and a hydronium-selective column of high capacity--a CS12 column, was employed. Since the retention time shift was reduced, the interval between onset and the complete elution of a high concentration ammonium standard (10 mg/l) was directly defined as the column-switching time window, which greatly simplified the procedure for determining the time window. Results showed that for ammonium below 1 mg/l, 90% ammonium was introduced and concentrated. Detection limits of 12.8 microg/l were obtained for ammonium with sodium at 1000 mg/l.