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。     

离子色谱法及聚类分析研究主流烟气中的有机酸

建立了超声辅助萃取-离子色谱法同时测定卷烟主流烟气中主要有机酸的方法.采用20 mL 30 mmol/L J NaOH溶液在50℃下对捕集了卷烟主流烟气的剑桥滤片超声萃取50 min,AS11-HC分离柱、Ion AG11-HC保护柱、ASRS-ULTRAⅡ抑制器,KOH溶液为淋洗液,用电导检测器同时测定了卷烟主流烟气中的乳酸、甲酸、乙酸、丙酸、苹果酸和草酸的含量.方法的线性范围1.0～400 mg/L,相关系数为0.9990～0.9995,相对标准偏差1.4%～4.8%,检出限0.03～0.09 mg/L,回收率为92%～104%.采用此方法测定了19种不同规格卷烟样品主流烟气中6种有机酸的含量,并且以6种有机酸为指标对样品进行了聚类分析.结果表明,6种有机酸的含量分布特征可反映不同等级卷烟产品的特性,可用于不用等级卷烟产品的比较和分类.     

在线基体消除-离子色谱法测定墨水染料中的氯及硫酸盐

建立了一种在线基体消除的方法,采用离子色谱法测定了墨水染料中的氯和硫酸盐。样品经溶解、稀释后直接进样,在纯水的输送下依次经过DIONEX OnGuard Ⅱ P和IonPac NG1柱,在线实现了墨水样品中染料和疏水性干扰基体的去除,死时间流出的待测阴离子浓缩于阴离子交换柱IonPac AG11-HC。浓缩柱经阀切换进入离子色谱系统,以4.5 mmol/L Na2CO3-0.8 mmol/L NaHCO3作为淋洗液,流速1.2 mL/min,待测离子经IonPac AS23（4 mm×250 mm）分析柱分离,采用DIONEX DS6电导检测器检测,外标法定量。Cl－和SO2-4的线性范围分别为0.05~5.0、0.1~10.0 mg/L,相关系数分别为0.999 8和 0.999 7,加标回收率为94%~103%,相对标准偏差（n=11）小于1.0%,检出限（S/N=3）分别为0.02、0.05 mg/L。该方法用于墨水染料中氯和硫酸盐的测定,结果满意。     

二维液相色谱接口的改进及其在蛋白质组学研究中的应用

随着蛋白质组学、本草物质组学等组学概念的提出,所需分析的样品的成分越来越复杂,因此具有强大分离能力的多维液相色谱技术受到人们越来越多的关注。二维液相色谱中第二维的分离性能和速度是整个分离系统性能的关键。基于捕集柱模式,我们采用经特殊设计的流路系统,使得双捕集柱型接口具有预分离的功能。样品从第一维流出以后被富集在捕集柱1的柱头,经过脱盐后,正冲捕集柱,捕集柱1与第二维色谱柱联用对富集的样品进行分离,增加了第二维分离效率。当捕集柱上的样品全部被洗脱到第二维色谱柱上时,捕集柱2已经完成对第一维洗脱液中样品的捕集和脱盐,此时将阀进行切换,捕集柱2与第二维色谱柱直接相连进行洗脱。循环切换捕集柱1和捕集柱2,维持较高的阀切换频率,实现了第二维色谱柱的连续洗脱。因此保证了第二维分离具有较快速度,同时具有较高的分离效率。使用35 mm长捕集柱和十通阀为接口,以弱阴离子交换(WAX)色谱为第一维分离模式,以反相(RP)色谱为第二维分离模式,构建了WAX-RP二维液相色谱系统(2D-LC system)。以小鼠血清为样品对系统进行了初步评价。色谱流出曲线出现了明显的界面现象,这是由于捕集柱流动相中含有的较多盐分流出时的背景吸收造成的。同时,由于界面两侧的流动相黏度不同产生了黏性指进(VF)现象。当第二维色谱柱长度为50 mm时,理论上可将第二维分离效能提高70%。该接口可以应用于多种二维液相色谱模式,适用于蛋白质组学和本草物质组学研究中对于复杂样品的分离分析。     

烟草中9种有机酸的梯度离子色谱法测定研究

采用淋洗液自动发生一梯度离子色谱分离,电导检测法分离测定了烟草中的甲酸、乙酸、乳酸、丙酸、丁酸、苹果酸、丙二酸、草酸和柠檬酸,并研究了9种有机酸在阴离子交换色谱中的保留行为.以淋洗液自动发生器生成的KOH为淋洗液,样品经提取、过滤稀释后,在IonPac AS1l-HC阴离子交换色谱柱上分离,抑制电导检测器进行检测,一次...     

阀切换-离子色谱法测定高纯硼酸中的痕量阴离子

研究了高纯硼酸中痕量阴离子的离子色谱测定方法.建立了使用阈切换技术联合离子色谱同时测定高纯硼酸中痕量阴离子的检测方法.样品经水溶解后,通过阀切换技术,使用蠕动泵和IonPac TAC-ULPI超低压浓缩柱,消除基体中硼酸根的干扰,同时在线富集样品中的阴离子,最后使用IonPac AS15分析柱进行分离.在20～500μg/L浓度范围内,7种常见阴离子的工作曲线的线性相关系数r均优于0.995,对硼酸样品进行加标,7种阴离子的平均回收率为90%～106%.该方法可应用于高纯硼酸中痕量阴离子的检测.     

离子色谱法分析磷脂纯化工艺回收乙醇中的乳酸、甲酸和乙酸

建立了同时分析磷脂纯化工艺回收乙醇中乳酸、甲酸和乙酸的离子交换色谱法。采用阴离子交换柱,以4 mmol/L NaHCO3溶液作流动相,样品中的有机酸(乳酸、甲酸和乙酸)在13 min内达到基线分离。采用抑制型电导检测,有机酸的检出限在0.03～0.04 mg/L之间。加标回收率在87.5%～102.4%之间。方法可用于磷脂纯化工艺监控和产品质量监测。     

直接电导检测离子排斥色谱法测定C1～C6脂肪族有机酸

建立了直接电导检测离子排斥色谱分离测定C1~C6脂肪族有机酸(甲酸、乙酸、丙酸、丁酸、戊酸、己酸)的方法。以Shim-pack SCR-102H 色谱柱为分离柱,选用p-甲苯磺酸水溶液为流动相,考察了流动相中p-甲苯磺酸的浓度、流速、pH、色谱柱温度对分离和测定脂肪族有机酸的影响,确定了最佳的色谱条件为：0.2 mmol/L p-甲苯磺酸水溶液作为流动相,流速1.2 mL/min,柱温45 ℃。所测有机酸的检测限为0.03～0.99 mg/L,相对标准偏差在2.3%以下(n= 5),回收率为91.2%～105.6%,整个分析过程在28 min内完成。该法用于白酒样品的分析,结果令人满意。     

碱稳定样品法测定降水中3种有机酸

建立了氢氧化钠稳定样品的离子色谱梯度淋洗测定大气降水中3种有机酸(乙酸、甲酸、草酸)的分析方法。用淋洗液在线发生器(RFC-30)产生梯度氢氧化钾溶液,以及Ion Pac AS19分离柱、IonPacAG19保护柱,确定了最佳梯度淋洗程序,可在36 min内同时测定大气降水中有机酸(乙酸、甲酸、草酸)和无机阴离子。并探讨了乙酸、甲酸、草酸标准溶液的稳定性,在有机酸标准溶液调为碱性(pH≥10)条件下,且于4℃下冷藏密封保存,乙酸、甲酸、草酸在10天内具有较好的稳定性。如空白试验中有微量甲酸、氯离子,实际样品和标准溶液测定时需相应扣减。乙酸、甲酸和草酸线性回归方程相关系数均大于0.999 5,方法检出限分别为0.002、0.003、0.002 mg/L,实际降水样品测定时乙酸、甲酸、草酸的相对标准偏差在0.3%～3.3%,加标回收率在93.0%～105.0%。本方法检出限低、精密度、准确度好,操作简便、灵敏、实用,可应用于实际大气降水分析,为相应标准方法(HJ1004-2018)提供了参考。     

淋洗液自动发生-离子色谱法同时测定食品中的21种有机酸

建立了一种利用离子色谱法同时测定样品中奎尼酸、乙酸、丙酮酸、草酰乙酸、甘露酸、乳酸、琥珀酸、苹果酸、酒石酸、草酸、富马酸、抗坏血酸、α-酮戊二酸、肉桂酸、水杨酸、柠檬酸、异柠檬酸、阿魏酸、顺乌头酸、反乌头酸、β-香豆酸等21种有机酸的方法。样品经提取、脱色、过滤后用IonPac AS11分离柱分离,以EG40自动淋洗液发生器生成的5~34 mmol/L KOH为淋洗液洗脱,抑制电导检测器检测。21种有机酸的浓度与其峰面积在一定的范围内呈良好的线性关系,检出限均低于0.188 mg/L,加标回收率为91.5%~101.8%。该法用于多种食物样品中有机酸的测定,结果令人满意。     

离子色谱法测定水中4种有机酸

建立了水样中甲酸、乙酸、丙烯酸和甲基丙烯酸的离子色谱测定方法,采用IonPac AS11-HC阴离子分离柱,以KOH为淋洗液,采用浓度梯度洗脱,可同时测定上述4种有机酸。方法对实际水样中甲酸、乙酸、丙烯酸和甲基丙烯酸的平均加标回收率在80.2%~103.3%,相对标准偏差在5.8%之内,检出限分别为:0.005,0.003,0.005和0.004mg/L;定量下限分别为:0.020,0.012,0.020和0.016mg/L。方法准确、简便、环保,能够满足实际水样的测定需要,且水样中常见的阴离子不会对目标污染物的测定产生影响。     

Determination of volatile fatty acids in landfill leachates by ion-exclusion chromatography

An ion-exclusion chromatographic method with on-line desalinization for the determination of volatile fatty acids in landfill leachates is described. Highly sensitive conductivity detection of the organic acids was achieved by using dilute p-hydroxybenzoic acid solution as an eluent. Interference with mineral acids was reduced by treatment with barium chloride solution prior to desalinization. A silver-loaded cation-exchange guard column for the desalinization was installed in series with the analytical column to avoid the contamination of organic acids. This method features detection limits of 0.01 mg L(-1) formic acid, 0.02 mg L(-1) acetic acid, 0.05 mg L(-1) propionic acid, and 0.1 mg L(-1) butyric acid, respectively, with an injection of 20 microL sample. Application of the on-line desalinization LC method is illustrated for leachate samples from a Japanese sanitary landfill.     

离子排斥色谱法测定环境样品中挥发性有机酸及乳酸

提出了同时测定环境样品中挥发性有机酸及乳酸的离子排斥色谱法（IEC法）。考察了流动相浓度、流速对有机酸分离的影响。实验结果表明,乳酸、甲酸、乙酸、丙酸、正丁酸和正戊酸可达到完全分离,被测组分的浓度与其峰高在一定的范围呈良好的线性关系,检出限均低于0.10 mg/L。测定了糖蜜酒精废水和消化污泥中有机酸的含量,结果满足检...     

Effect of stationary phase hydrophobicity and mobile phase composition on the separation of carboxylic acids in ion chromatography

In a previous work, we studied the retention behavior of monovalent and divalent carboxylic acids on a highly cross-linked polystryene-divinylbenzene anion-exchange column (IonPac AS4A-SC) using a carbonate-based buffer, and a retention model was applied to the chromatographic data obtained. In this work we characterized the retention of carboxylates (formic, acetic, propionic, lactic, pyruvic, oxalic, malonic, succinic, fumaric, maleic, tartaric, glutaric, adipic, malic, mucic, trans-beta-hydromuconic, trans,trans-muconic acids) on a column with higher hydrophilicity (IonPac AS11) according to analyte and stationary phase properties, using previously investigated eluent compositions and comparing the retention data obtained. Moreover, the effect of organic modifiers (CH3OH and CH3CN) in the eluent on the retention factors was also evaluated. The chromatographic data obtained on the IonPac AS11 column were fitted by the retention model and allowed one to obtain and to compare ion-specific selectivity constants (parameters of the model) with the ones obtained with the previous column.     

Analysis of anions in alkaline solutions by ion chromatography after solid-phase extraction

An Ion Chromatographic (IC) method for the determination of six organic acids and three inorganic anions in alkaline solutions was reported. Formic, acetic, propionic, oxalic, succinic, glutaric acid, F-, Cl-, and SO4(2-) were separated and determined in 33 min. The analytes were removed from Bayer liquor by using an ion-exchange resin column. The chromatographic separation was achieved with only one IonPac AS11-HC column thermostated at 30 degrees C. Organic acids and inorganic anions were detected with a suppressed conductance detector. The precision results' showed that the repeatability and reproducibility were < 2.94 and < 1.37%, respectively. The accuracy of the method was assessed by the recoveries ranging from 86.3 to 105.6%. Under optimum conditions the detection limits ranged from 0.008 to 0.053 mg/l.     

Determination of short chain aliphatic acids in silage effluents by ion exclusion chromatography

Summary Short chain aliphatic acids are important components of the dissolved organic matter in silage effluents. Although ion exclusion chromatography offers some advantages for the analysis of these compounds, no attempt has yet been made to prove the suitability of this method for silage effluent analysis. In order to gain experience in this field, the separation characteristics of a Dionex ion exclusion column (IonPac-ICE As5) have been evaluated, the separation conditions have been improved, and several sample clean-up methods have been checked.Ten effluents generated during silaging of five different crops were collected from Bavarian farms and analyzed. Lactic and acetic acids were the predominant aliphatic acids. Pyruvic, formic, propionic, and succinic acid were detected in all samples, whereas glyceric and iso-citric acid were found in a few samples only.If some restrictions of substance specificity and separation efficiency can be accepted, the analytical method presented will be a reliable tool for the analysis of carboxylic acids in silage effluents.     

离子交换色谱法对8种有机酸含量的同时测定

建立了淋洗液自动发生梯度淋洗的离子交换色谱法同时测定果汁中乳酸、乙酸、苹果酸、丙二酸、马来酸、草酸、柠檬酸、异柠檬酸8种有机酸的分析方法.样品经处理后用lonPac AS11-HC分离柱和lonPac AG11-HC型保护柱分离,以EG40自动淋洗液发生器生成的0.8～30 mmol/L KOH为淋洗液梯度洗脱,抑制型...     

Efficient separation of acetate and formate by ion chromatography: application to air samples in a cultural heritage environment

A method for the separation of acetate and formate anions by ion chromatography has been optimized under various measurement conditions (e.g. the composition of the mobile phase, and the flow rate of the eluent). For this purpose, two different analytical columns were examined: the IonPac AS14 (250 mm x 4 mm i.d.; designed mostly for the separation of inorganic anions) and the Allsep A-2 (150 mm x 4.6 mm i.d.; designed for the separation of low-molecular mass organic acids). However, nearly baseline separation of acetate and formate has been found on each column using the following conditions: (i) IonPac AS14 column and 2.0 mM Na2B4O7 solution as an eluent with a flow rate of 1.0 ml/min, or (ii) Allsep A-2 column and an eluent containing a mixture of 1.2 mM Na2CO3 plus 1.5 mM NaHCO3 with a flow rate of 1.3 ml/min. Additionally, the separation of fluoride from acetate and formate on both columns was studied. On the IonPac AS14 column it was possible to separate all three investigated anions. However, on the Allsep A-2 column, when the concentration of fluoride was comparable to, or higher than acetate, it was impossible to achieve good separation of these two anions, even using the optimized elution procedure. Therefore, the measurements of real samples were carried out with the use of IonPac AS14 column. The concentrations of acetate and formate have been determined in the air samples of the Cathedral of Cologne (Germany), after sampling the corresponding acids by passive diffusion tubes. Average concentrations of 122 and 9 microg/m(3) for acetic and formic acids were found, respectively, inside the Cathedral and in a depot with medieval stained glass panels.     

Analysis of carbonic acid in water samples by ion-exclusion chromatography with pure water as eluent.

A simple, sensitive and rapid ion-exclusion chromatographic method for the simultaneous separation of carbonic acid and short chain organic acids (formic acid, acetic acid, and propionic acid) has been developed. A weakly acidic cation exchange resin column TSKgel OApak-A was used for the separation; pure water, owing to its lower background conductance, was employed as eluent in order to obtain high detection sensitivity. A good separation of these weak acids was achieved in 16 min. The linear range of the peak area calibration curve for carbonic acid was from 3.0 mg/L to 500 mg/L. The conductivity detection limit calculated at S/N = 3 was 0.084 mg/L for carbonic acid. The method developed in this work was successfully applied to the determination of carbonic acid in several environmental water samples without any pretreatment.