氧化铝柱预分离-离子色谱法测定钢铁中痕量硫

采用２．２５ｍｍｏｌ／Ｌ邻苯二甲酸氢钾为流动相,以单柱阴离子色谱法测定痕量硫,硫的检出限达３μｇ／Ｌ,详细研究了氧化铝柱分离条件,实现了钢铁中痕量硫与基体快速分离并定量回收,消除了酸溶路线中大量杂质离子的干扰及重金属离子对色谱柱的危害,研究了不同基体对痕量硫测定的干扰情况及消除方法,建立了氧化铝柱预分离－ＩＣ法测定钢铁中痕量硫的新方法。     

离子色谱法同时测定海洋沉积物中氯和硫

建立了用艾斯卡试剂熔样,OnGuard-H小柱净化分离,离子色谱法同时测定海洋沉积物中氯和硫的分析方法。考察了熔样温度、装样容器及净化方法等影响因素,优化了实验条件。实验选用IonPac AS19色谱柱,以NaOH溶液作为流动相进行淋洗,测定了海洋沉积物国家标准物质(GBW07313)的氯和硫,氯和硫的测定结果平均值分别为4.02%和0.31%,与标准值4.07%和0.31%相符,相对标准偏差分别为1.67%和4.41%,说明该方法的精密度和准确度良好,能够满足地质样品的分析需要。同时选取了5个海洋沉积物样品进行测定,并与X射线荧光光谱法(XRF)进行了比较,两者测定结果一致。     

离子色谱法测定糖蜜中总硫

将糖蜜置于充满氧气的石英瓶中燃烧,样品中的硫转化为硫的氧化物,然后用20mL含有5滴30%的H2O2的水溶液吸收30min使氧化物成为硫酸根。在淋洗液为V(Na2CO3)∶V(NaHCO3)=1.8∶1.7的离子色谱条件下测定硫酸根,从而获得糖蜜中的总硫。方法的回收率为94.2%～106.3%,线性范围为0.02～60μg/mL,检出限为0.00324μg/mL。该方法具有操作简单,较宽的线性范围和低的检测限,准确度高,精密度好的优点。     

离子色谱法同时测定扇贝柱中多种磷酸盐

建立了一种简单、快捷的离子色谱测定扇贝柱中多种磷酸盐的方法。采用超声提取、固相萃取柱净化的方法对样品进行前处理,高容量阴离子交换色谱柱分离,抑制性电导检测器检测。讨论了不同实验条件对多种磷酸盐检测结果的影响。实验证明:磷酸钠检出限为40mg/kg,焦磷酸钠、三聚磷酸钠、三偏磷酸钠均为10mg/kg,回收率在74.8%以上,相对标准偏差(RSD)小于10.7%,实际样品检测结果令人满意。方法具有简便、快捷,选择性好,灵敏度高,无污染、操作步骤简单等优点。     

柱切换离子色谱法测定丙酮中痕量阴离子

建立了测定丙酮中痕量阴离子的离子色谱分析方法.采用的是高效液相柱切换进样,其中泵的流速为0.5 mL/min,使低浓度的丙酮水溶液在保护柱上富集,通过离子色谱抑制电导法分离和检测丙酮样品中痕量的阴离子.色谱条件为:以IonPacAG9-HC(50 mm×2 mm)型柱串联在定量环中进行富集,IonPacAG9-HC(50 mm×2 mm)保护柱,IonPac AS9-HC(250 mm×2 mm)阴离子分离柱进行分离,流动相为9 mmol/L Na2CO3-1.667 mol/L NaHCO3,所得回收率在96.21%～101.56%之间,线性良好,且具有较好的重现性和较低的检出限.     

柱后衍生-离子色谱法测定面粉中痕量溴酸盐的研究

溴酸盐在面粉发酵、醒发及焙烤工艺中起缓慢氧化作用,可明显改善面团结构和性能。20世纪80年代发现溴酸盐有致癌作用,被国际癌症研究机构列为2B致癌物质。我国卫生部规定从2005年7月起禁止溴酸盐在食品中使用。面粉中溴酸钾含量的测定,我国还没有相应的标准检验方法。因此,提出     

丙烯中微量硫的测定

本文采用燃烧方法将不同形式的可燃性硫转化为SO2，在硝酸介质中用H2O2将SO2氧化为SO4^2-，并用离子色谱法测定。结果表明，该法样品处理简单，干扰离子少，灵敏度高，能较准确测定出丙烯中的微量硫。     

离子色谱法检测酸性镀铜液中的微量氯离子

采用Na2CO3-NaHCO3为淋洗液和抑制电导检测,对酸性镀铜液中的微量氯离子进行检测。采用AgNO3作为沉淀剂使Cl-分离富集,再用Na2S2O3溶液溶解沉淀后进行检测,可以很好地消除酸性电镀液中高浓度SO4^2-的干扰。该方法线性良好,Cl^-的检出限为0.01μg/mL,回收率在98.6%-101.7%之间,由于该方法能够很好地消除大量SO4^2-的干扰,在电镀铜工业中对酸性镀铜液中氯离子的监控可发挥作用。     

Determination of anions by non-suppressed ion chromatography using an amine column

Summary The Synchropak AX300 column has been used to separate a wide range of anions. A standard solution containing F^–, Cl^–, NO ₂ ^– , NO ₃ ^– , HPO ₄ ^2– , SO ₄ ^2– ions can be analysed in 8–14 minutes using a phthalate or phthalate/citrate eluent at pH 6–7. Addition of citrate to a phthalate eluent has a pronounced effect on the times of analysis. Detection by direction and indirect UV absorption enables the analysis of a wide range of anions. Application of the technique range from rain water to ash pond liquor analysis.     

超高含量氯离子基体下痕量亚硝酸盐的检测

介绍了一种无需对样品进行除氯处理,采用全新的离子色谱柱,抑制型电导离子色谱法检测,测定超高Cl-基体下痕量亚硝酸盐及其它常见阴离子的方法.其中Cl-浓度与亚硝酸盐浓度比可达到50000:1甚至100000:1,实现良好分离.选择色谱条件为:IonPac AS23阴离子交换柱,手工配制碳酸盐淋洗液等度淋洗,抑制型电导检测.污水样品通过Dionex OnGuardⅡRP柱和0.22 μm微孔尼龙膜处理.该方法采用25 μL进样,8种常见阴离子的检出限为0.2～5.8μg/L,线性范围均超过2个数量级,相关系数r在0.9996～0.9999的范围内,连续11次进样检出所有阴离子的RSD均小于5%,加标回收率结果在93%～106%之间.该方法具有选择性好,灵敏度高,操作简单等特点,从根本上解决了高氯离子基体中痕量亚硝酸盐及其它常见阴离子检测的问题,用于实际污水样品的检测.     

Determination of trace inorganic anions in seawater samples by ion chromatography using silica columns modified with cetyltrimethylammonium ion

Conventional silica columns dynamically modified with cetyltrimethylammonium ions were evaluated for the determination of UV-absorbing bromide, nitrate, and nitrite in seawater samples. Cetyltrimethylammonium, which is a quaternary ammonium ion, was dynamically introduced onto silica surfaces. The first layer of the modifier was introduced by electrostatic interaction, whereas the second layer was introduced by hydrophobic interaction. The latter layer worked as the anion-exchange sites. The modified conventional silica columns could be used for separation of inorganic anions. Separation of authentic mixture of five anions was achieved within 17 min. The addition of 0.1 mM cetyltrimethylammonium ion to the eluent improved the repeatability of the retention time. Seawater samples could be directly injected onto the prepared conventional silica columns, and bromide, nitrate, and nitrite levels were determined to be 69, 0.13, and 0.016 ppm, respectively.     

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％。     

Two-dimensional ion chromatography using tandem ion-exchange columns with gradient-pulse column switching

A two-dimensional ion chromatography (2D-IC) approach has been developed which provides greater resolution of complex samples than is possible currently using a single column. Two columns containing different stationary phases are connected via a tee-piece, which enables an additional eluent flow and independent control of eluent concentration on each column. The resultant mixed eluent flow at the tee-piece can be varied to produce a different eluent concentration on the second column. This allows analytes strongly retained on the first column to be separated rapidly on the second column, whilst maintaining a highly efficient, well resolved separation of analytes retained weakly on the first column. A group of 18 inorganic anions has been separated to demonstrate the utility of this approach and the proposed 2D-IC method provided separation of this mixture with resolution of all analytes greater than 1.3. Careful optimisation of the eluent profiles on both columns resulted in run times of less than 28 min, including re-equilibration. Separations were performed using isocratic or gradient elution on the first column, with an isocratic separation being used on the second column. Switching of the analytes onto the second column was performed using a gradient pulse of concentrated eluent to quickly elute strongly retained analytes from the first column onto the second column. The separations were highly repeatable (RSD of 0.01–0.12% for retention times and 0.08–2.9% for peak areas) and efficient (typically 8000–260,000 plates). Detection limits were 3–80 ppb.     

Determination of the sulfur components of gasoline streams by capillary column gas chromatography with sulfur chemiluminescence detection

A method using a sulfur chemiluminescence detector (SCD) has been developed for the qualitative and quantitative determination of sulfur components in stabilized gasoline-range process streams, including blended gasolines containing between 1 and > 4000 ppm total sulfur. The detection limit per sulfur component was approximately 50 ppb. On-column injection was employed for optimum precision and accuracy. A new probe material was found which did not soften under FID operating conditions. A new method, using a hydrogen sulfide permeation tube, was developed for rapid alignment of the probe in the FID.     

微波消解－离子色谱法测定染料中痕量阴离子

建立了染料痕量阴离子的微波消解离子色谱方法。对离子色谱的干扰,pH对分离效果影响,淋洗液的选择对保留时间的影响,流速对峰高、峰面积、分离度和理论谈板数的影响进行了研究。结果表明：六种阴离子具有良好的线性关系,相关系数为0.9991-0.9999,检出限为0.0002-0.0032mg/L,加标回收率为97.6%-101.4%,阴离子精密度＜0.03%-2.55%,仪器定量和定性精密度＜3.0%,本方法精密、准确、快速,对氮杂BODIPY荧光染料2,6－位置引入卤素的含量测定具有实际应用价值。