Novel additives for the separation of organic acids by ion-pair chromatography

This paper proposes the use of novel surfactant additives for the separation of organic acids by ion-pair chromatography and studies the influences of surfactants on the chromatographic separation behaviors.Researches have been carried out on both silica gel matrix and polymer supporters in order to compare the two ordinary kinds of stationary phases,and the phenomenon is similar. Separation is based on differences in the stabilities of analyte-additive complexes in solution.Retention times of analytes can ...

Enantiomeric Separation of Amino Alcohols by Ion-pair Chromatography

Enantiomers of four amino alcohols were resolved by ion-pair chromatography with (+)-10-camphorsulphonic acid as chiral counter ion. Studies of the influence of the mobile phase composition, the solute structure and the mobile phase flow-rate on separation are presented. Under the optimized conditions enantiomeric propanolol, norephedrine, metropolol and salbutamol were separated using dichloromethane-1-pentanol (97:3 v/v) as mobile phase on Lichrospher-100-DIOL column.

INVESTIGATION ON SEPARATION OF INORGANIC ANIONS BY REVERSED-PHASE ION-PAIR LIQUID CHROMATOGRAPHY

Ⅰ. INTRODUCTIONReversed-phase ion-pair liquid chromatography is widely used in the separation of ionized organic compounds. In recent years, the separation of inorganic ions by the reversedphase ion-pair liquid chromatography with indirect UV detection or conductivity

Determination of Cyanuric Acid in Milk Powder and Swimming Pool Water by Ion-pair Reversed-phase Liquid Chromatography

An ion-pair reversed-phase high-performance liquid chromatographic method, using tetrabutylammonium bromide （TBAB） as ion-pair reagent, has been developed for the analysis of cyanuric acid （CA） in milk powder and swimming pool water. It was found that the effect of the concentrations of ion-pair reagent on the retention of cyanuric acid was different for standard solution and different real samples. The separation was carried out on a reversed-phase C18 column with 85 ： 15 （V/V） water-acetonitrile （ACN） containing different concentration of TBAB as mobile phase for different samples. The linear range of the calibration curve for CA was 0.1-100 mg·L^-1 The detection limits calculated at S/N=3 was 0.11 mg-L^-1 for the analysis of milk powder and 0.31 mg·L^-1 for the analysis of swimming pool water, respectively. The method was successfully applied to the analysis of CA in milk powder and swimming pool water.

盐酸丙卡特罗片有关物质的HPLC检查研究

目的:建立盐酸丙卡特罗片有关物质的HPLC测定法。方法:采用Inertsil ODS-3(4.6 mm×250 mm,5μm)色谱柱,以10 mmol·L^(-1)辛烷磺酸钠溶液(用10%磷酸调节pH值至2.90)为流动相A,水-乙腈(43∶57,V∶V)为流动相B,进行梯度洗脱,检测波长为254 nm,柱温为40℃,流速为1.0 mL·min^(-1),进样量为50μL。结果:盐酸丙卡特罗与各有关物质色谱分离度良好,杂质A、B、C质量浓度在10~50 ng·mL^(-1)范围内与峰面积线性关系良好(r>0.9990),校正因子分别为0.5、1.0、0.4,平均回收率为95.0%~105.0%(n=9,RSD<3.0%)。结论:所建立的HPLC方法适用于盐酸丙卡特罗片的有关物质检查,可为盐酸丙卡特罗片现有标准的进一步完善提供参考。

采收期、生长年限和加工方法对黄花乌头不同部位中关附甲素含量的影响

目的:为规范黄花乌头的人工栽培,通过优化高效液相法,对不同采收时期、生长年限黄花乌头不同部位中关附甲素的含量进行测定,比较不同加工方法对关附甲素含量的影响,为制定黄花乌头合理的采收时间和加工方式提供依据。方法:采用反相离子对高效液相色谱法,测定黄花乌头中不同部位中关附甲素的含量;色谱柱为安捷伦Zorbax SB-C18柱(250 mm×4.6 mm,5μm),流动相A为2 mg/mL庚烷磺酸钠水溶液(含0.2%三乙胺并以H_(3)PO_(4)调pH值至3.0),流动相B为乙腈,采用梯度洗脱,流速为1.0 mL/min,检测波长为205 nm,柱温20℃。结果:关附甲素的质量浓度在0.0251~0.2513 mg/mL^(2)范围内线性关系良好(R^(2)=1),精密度、重复性、稳定性试验结果的RSD均≤1.0%;平均加样回收率为97.83%,RSD为3.5%。不同采收期黄花乌头不同部位中9月份采集的样品子根含量最高,说明9月份为最佳采收期。不同生产年限样品中,三年生和三年以上生黄花乌头母根含量相差不大,但均大于两年生母根,地上部分中所含关附甲素都明显小于根部。不同加工方法所得关白附中关附甲素的含量大小依次为:阴干>晒干>炕干,说明不同条件对含量的影响较大。结论:建立的含量测定方法专属性强、精密度、重复性和稳定性较好,结果可靠,黄花乌头的最佳采收期为9月份,生长期限为3年,本研究为黄花乌头科学的人工栽培采收提供了实验依据。

基于离子对竞争性结合作用检测牛肉中16种氨基糖苷类兽药残留

建立同时测定牛肉中16种氨基糖苷类兽药残留的方法。样品经磷酸盐缓冲液提取,三氯乙酸沉淀蛋白,调节pH值后,HLB固相萃取小柱净化,Hilic Plus色谱柱分离,在电喷雾电离正离子模式下采用超高效液相色谱-串联质谱检测。结果表明,16种氨基糖苷类兽药在25~750μg/kg内线性关系良好,相关系数均大于0.990,检出限为0.006~0.609μg/kg,定量限为0.02~1.83μg/kg。在牛肉中加标回收率为69.09%~115.50%,相对标准偏差为1.04%~16.58%(n=6)。本方法灵敏度、准确度高,适用于牛肉中16种氨基糖苷类兽药的同时测定。

PEAK IDENTIFICATION FROM INTERACTION INDEX IN REVERSED-PHASE HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY

The interaction index c which was derived from the fundamental retention equationlogk’ =a + cC_B in reversed--phase high--performancc liquid chromatography (RP-HPLC) quan-titatively describes the difference in the interaction between solute--strong. solvent andsolute--weak solvent; it has shown to be a constant for a specific solute even when columnsystems with different C18 packings are used. The theoretical basis for peak identificationby using interaction index has been proposed, which was based on the a,c values on stan-dard C18 column by utilizing linear a-a plots on column pairs and the linear relationship be-tween parameters a and c for the structural related compounds. Through the establishmentof parameters a,c data based on the standard C18 column for a certain type of compounds,the retention of thesc compounds on various C18 columns can be predicted. Typical exam-ples have been given to verify the correctness of this method.

Rapid and simultaneous determination of imidazolium and pyridinium ionic liquid cations by ion-pair chromatography using a monolithic column

A method for rapid and simultaneous determination of imidazolium and pyridinium ionic liquid cations by ion-pair chromatography with ultraviolet detection was developed. Chromatographic separations were performed on a reversed-phase silica-based monolithic column using 1-heptanesulfonic acid sodium-acetonitrile as mobile phase. The effects of ion-pair reagent and acetonitrile concentration on retention of the cations were investigated. The retention times of the cations accord with carbon number rule. The method has been successfully applied to the determination of four ionic liquids synthesized by organic chemistry laboratory.

Determination of tetraethyl ammonium by ion-pair chromatography with indirect ultraviolet detection using 4-aminophenol hydrochloride as background ultraviolet absorbing reagent

A method was developed for the determination of tetraethyl ammonium （TEA） by reversed-phase ion- pair chromatography with indirect ultraviolet detection, Chromatographic separation was achieved on a reversed-phase C18 column using background ultraviolet absorbing reagent - ion-pair reagent - organic solvent as mobile phase. The effects of the background ultraviolet absorbing reagents, detection wavelength, ion-pair reagents, organic solvents and column temperature on the determination method were investigated and the retention rules discussed. Results found that TEA could be successfully analyzed by using 0.7 mmol/L 4-aminophenol hydrochloride and 0.15 mmol/L 1-heptanesulfonic acid sodium mixed with 20% （v/v） methanol as mobile phase at a UV detection wavelength of 230 nm. Under these conditions, the retention time of tetraethyl ammonium was 2.85 min. The detection limit （S/N = 3） for TEA was 0.06 mg/L. The relative standard deviations （n = 5） for peak area and retention time were 0.35% and 0.02%, respectively. The method has been successfully applied to the determination of synthesized tetraethyl ammonium bromide. Recovery of tetraethyl ammonium after spiking was 99.1%.

离子对色谱-抑制电导法测定6-溴己基三甲基溴化铵中相关物质

建立了离子对色谱法测定6-溴己基三甲基溴化铵中相关物质的分析方法。样品经超纯水溶解后过0.22μm滤膜进样分析,选用Shinesil C18色谱柱进行色谱分离,高氯酸和乙腈作为淋洗液进行梯度洗脱,采用电导检测器检测,外标法定量。结果表明,6-溴己基三甲基溴化铵和溴化六甲铵的峰面积与其质量浓度在一定范围内呈良好线性关系,检出限分别为1.076 mg/L、0.2327 mg/L,定量限分别为3.587 mg/L、0.7757 mg/L。以6-溴己基三甲基溴化铵样品进行加标回收试验,回收率在95.8%~103.3%之间,测定值的相对标准偏差(RSD,n=6)均小于1.10%。该方法简单快速,可用于6-溴己基三甲基溴化铵样品中主成分6-溴己基三甲基溴化铵和杂质溴化六甲铵的定性和定量分析。

Fast analysis of thiocyanate by ion-pair chromatography with direct conductivity detection on a monolithic column

Fast analysis of thiocyanate by ion-pair chromatography using a silica-based monolithic column and direct conductivity detection was carried out. Chromatographic separation was performed on a Chromolith Speed ROD RP-18e using tetrabutylammonium hydroxide （TBA）-phthalic acid-acetonitrile as eluent. The effects of eluent concentration, eluent pH value, column temperature and flow rate on retention time of thiocyanate were investigated. The optimized chromatographic conditions for the determination of thiocyanate were as follows： 0.25 mmol/L TBA-0.18 mmol/L phthalate-7% acetonitrile （pH 5.5） as eluent, column temperature of 30 ℃, and flow rate of 6.0 mL/min. Retention time of thiocyanate was less than 1 min under the conditions. Common anions （Cl^-, NO3 , SO42 and I^- ） did not interfere with the determination of thiocyanate. Detection limit （S/N = 3） of thiocyanate was 0.96 mg/L. Calibration graph between peak area and the concentration of thiocyanate was linear in the range of 2.0- 100.0 mg/L. Relative standard deviation （RSD） of chromatographic peak area was 1.4% （n = 5）. This method has been applied to the determination of thiocyanate in ionic liquids. Recoveries of thiocyanate after spiking were 100.5%.

三重四级杆气质联用仪测定固废中的19种有机磷农药

该方法采用三重四级杆气质联用仪dMRM测量方式,建立了固废中的19种有机磷农药的检测方法。固废中的有机磷农药经提取、净化处理后,采用三重四级杆气质联用仪dMRM测量方式进行检测。dMRM模式在检测目标化合物时有更好的选择性,更有效的除去基体干扰,可以实现了痕量的测定。其线性范围内均呈现良好的线性关系,线性系数0.999以上,该方法固体样品检出限为0.09~0.16 ug/kg,浸出液检出限为0.60~1.48 ug/L;该方法固体样品精密度为2.2%~12.1%,浸出液精密度分为2.5%~10.2%;加标回收率为70.0%~115.5%。该方法重现性好、精密度高、操作简单,适用于固废中多种有机磷的检测。

Rapid and simultaneous determination of piperidinium and pyrrolidinium ionic liquid cations by ion pair chromatography coupled with direct conductivity detection

A method of ion-pair chromatography with direct conductivity detection was developed on a silicabased monolithic column for the fast and simultaneous determination of piperidinium and pyrrolidinium ionic liquid cations. The effects of the mobile phase, column temperature and flow rate on the retention of the cations were investigated. The retention rules were discussed. As an ion-pair reagent, sodium heptanesulfonate is more suitable than sodium pentanesulfonate for the separation and determination of piperidinium and pyrrolidinium cations. The increase of ion-pair reagent concentration led to the increased retention time of the cations. When acetonitrile content and mobile phase flow were increased, the retention time of the cations became shorter. The retention of piperidinium and pyrrolidinium cations is an exothermic process, and the retention of the cations conforms to the carbon number rule. The chromatographic analysis was performed using the Chromolith Speed ROD RP-18 e column, 0.5 mmol/L sodium heptanesulfonate-5% acetonitrile as the mobile phase at a flow rate of3.0 m L/min and column temperature of 30℃. Separation of N-methyl-N-ethyl piperidinium, N-methylN-propyl piperidinium, N-methyl-N-butyl piperidinium and N-methyl-N-ethyl pyrrolidinium, Nmethyl-N-propyl pyrrolidinium, N-methyl-N-butyl pyrrolidinium cations were achieved within10 min. The detection limits（S/N = 3） were between 0.19 and 3.08 mg/L. Relative standard deviations（n = 5） for peak areas were less than 1.2%. The method has been applied to the determination of piperidinium and pyrrolidinium cations in ionic liquid samples. The spiked recoveries of ionic liquid cations were between 96% and 111%. The method is accurate, reliable, rapid, and has a better practicability.

离子对色谱法测定茶叶中的茶氨酸

通过添加十二烷基磺酸钠（SDS）为离子对试剂，以乙腈-水（磷酸）为流动相，在200nm的检测波长条件下，建立了一种快速测定茶叶中茶氨酸的分析方法。茶氨酸的保留时间为6。27min；在0．04-20μg范围内，茶氨酸峰面积与进样量之间有良好的线性关系，回归方程为：Y=1．51466×10^6X＋3．28706×10^5（r^2=0．99901）；当S／N=3时，最低检测浓度为1．15ng。所建方法快速，简便，准确，可用于茶叶中茶氨酸含量测定。

杀菌剂中抑霉唑含量的离子对高效液相色谱分析

选用庚烷磺酸钠作离子对试剂 ,拟定了杀菌剂中抑霉唑及其硫酸盐的反相离子对HPLC测定方法。讨论了离子对的形成过程 ,pH值对离子对形成的影响 ,推导了流动相pH值计算公式 ,估算了流动相的pH值范围 ,确定了色谱柱为EclipseXDB C815 0mm× 4 .6mm ,流动相为甲醇 :含 12mmol/L庚烷磺酸钠的 2 5mmol/L磷酸盐缓冲溶液 (pH≈ 2 .8) =6 2∶38(V/V) ,测定波长为 2 2 5nm的分析条件。方法的检出限为 7.1× 10 -4μg ;线性范围为 8.0× 10 -3 ～ 4 .0 μg ,实验结果线性关系良好 ;相关系数r =0 .9998。方法用于杀菌剂样中抑霉唑及其硫酸盐的测定 ,回收率 99.7% 。

离子对高效液相色谱法同时测定鱼类中四种喹诺酮类药物的残留

采用离子对高效液相色谱法同时测定了鱼类中4种喹诺酮类药物(FQS)的残留.检测条件为:采用Waters μBondapakTM C18柱,以11 mmol/L的四丁基溴化铵溶液-乙腈(体积比为94∶6)为流动相(用冰乙酸调pH为3.0,流速1.0 mL/min),柱温40 ℃;采用荧光检测器检测,激发波长280 nm,发射波长460 nm.测定结果表明,该方法对FQS的最低检测限为1 μg/kg,在6～100 μg/kg线性范围内,溶液含量与峰面积的相关系数达0.999 5以上.在高、中、低3种含量水平下对所测鱼组织中4种喹诺酮类药物进行回收率测定,结果为76% ～100% ,相对标准偏差小于7% .该法简便、准确,灵敏度高,符合痕量测定的要求.

离子对色谱法分离氨基醇类对映体

运用离子对色谱法 ,以 (+) 10 樟脑磺酸为手性离子对试剂 ,在二醇柱 (Lichrospher 10 0 DIOL)上 ,分离了苯丙醇胺、美托洛尔、普萘洛尔、肾上腺素和沙丁胺醇 5种氨基醇类对映体。考察了流动相组成和化合物结构对分离选择性的影响。选用的流动相为二氯甲烷 正戊醇 (97 3、V V、内含 2 .2× 10 - 3mol L的樟脑磺酸 ) ,流速为 0 .3mL min。苯丙醇胺、美托洛尔、普萘洛尔、肾上腺素和沙丁胺醇对映体的分离因子分别为 1.2 9、1.2 5、1.2 5、1.33和 1.2 9;它们的分离度分别为 1.5 5、1.78、1.83、1.89和 1.

反相离子对色谱-电感耦合等离子体质谱联用技术测定水中痕量Cr(Ⅲ)与Cr(Ⅵ)

建立了反相离子对色谱(RPIPC)与电感耦合等离子体质谱(ICP-MS)联用技术快速分离测定水中痕量Cr(Ⅲ)和Cr(Ⅵ)的方法。通过考察流动相的pH值、离子对试剂及甲醇的浓度和EDTA的添加等对不同形态铬的保留时间及分离度的影响,确定当流动相组成为2.0mmol/LTBA,5%(V/V)甲醇,pH=5.5时,Cr(Ⅲ)与Cr(Ⅵ)可达最佳分离。ICP-MS测定时选用碰撞池技术以消除40Ar12C+与35Cl16OH+对52Cr+的谱学干扰;进样100μL时,Cr(Ⅲ)与Cr(Ⅵ)的检出限分别为0.15μg/L和0.16μg/L。加标回收率在93.6%～106.2%之间;RSD<4%(n=3)。以本方法分析了某市自来水、雨水及某品牌纯净水中Cr(Ⅲ)与Cr(Ⅵ)的含量,结果令人满意。

反相离子对色谱法测定啤酒中的嘌呤类物质

利用反相离子对色谱法(RP-IPC)对啤酒中的腺嘌呤(Ade)、鸟嘌呤(Gua)、黄嘌呤(Xan)和次黄嘌呤(Hyp)等4种嘌呤类物质的测定方法进行了研究。结果表明,当检测波长254nm,流动相为水:甲醇:冰乙酸:四丁基氢氧化铵为883.5:100:15:1.5(V/V/V/V),流速为1ml/min时,方法精密度为1.41%～2.42%,测得四种嘌呤物质的回收率在91.2%～100.3%之间。啤酒中的含嘌呤类物质需要经高氯酸水解成嘌呤,经优化的水解条件为啤酒:高氯酸为1:2、100℃水解30min。