Retention Mechanism Studies of Selected Amino Acids and Vitamin B6 on HILIC Columns with Evaporative Light Scattering Detection

The goal of the study was to investigate separation mechanism of selected “essential” amino acids (leucine, isoleucine, threonine, tryptophan, proline, and glycine) and vitamin B6 in hydrophilic interaction liquid chromatography (HILIC) with the evaporative light scattering detection. Chromatographic measurements were made on three different HILIC columns: amide-silica (TSK-gel Amide-80), amino-silica (TSK-gel NH₂-100), and cross-linked diol (Luna HILIC). The retention behaviour of the analytes was investigated as a function of different binary hydro-organic mobile phases containing 10–90 % (v/v) acetonitrile. The compounds studied were separated under isocratic and gradient conditions. The best results of tested biologically active compounds separation were obtained on the TSK-gel NH₂-100 column. TSK-gel NH₂ column showed mixed HILIC–ion-exchange mechanism, the highest separation efficiency and better selectivity and resolution for tested analytes than the other studied column, especially at concentration of water in mobile phase lower than 30 % (v/v). Special attention was dedicated to the study of interactions among the stationary phase, mobile phase and the analytes.     

Validation of an Ion-Interaction Chromatography Analysis of Underivatized Amino Acids in Commercial Preparation Using Evaporative Light Scattering Detection

A liquid chromatographic procedure using ion interaction reagent and evaporative light scattering detection was developed and validated for the direct quantification of 8 underivatized amino acids (threonine, lysine, valine, methionine, isoleucine, leucine, phenylalanine and tryptophan) present simultaneously in a commercial preparation. The chromatographic separation was achieved on a Purospher RP-18e column with an acetonitrile gradient and using heptafluorobutyric acid as volatile ion interaction reagent. Acceptable levels of linearity, specificity, precision, accuracy, robustness and limits of detection were achieved during the validation of the method. Detection limits varied from 1 mg.L^–1 to 2 mg.L^–1 depending on the amino acid being analyzed. The results of this method agree to within 98.6%–102.5% when compared to the manufacturers certificate of analysis obtained with the standard amino acid autoanalyser method. This approach yields a simple, universal method that is well suited for amino acid analysis, when a sufficient quantity is available. Only basic LC instrumentation with an ELSD is necessary for this procedure.     

亲水色谱-蒸发光散射检测器定量分析白坚木皮醇含量

建立白坚木皮醇(Quebrachitol)含量的亲水作用色谱-蒸发光散射检测器(ZICHILIC-ELSD)测定方法。Merck ZIC-HILIC色谱柱(150×4.6mm,5μm);以乙腈-水(体积比为70∶30)为流动相,等度洗脱,流速为1.0mL/min;蒸发光散射检测器,蒸发温度为65℃,雾化温度为50℃,高纯氮压力9.9 MPa。结果表明,白坚木皮醇浓度与其色谱峰面积积分值呈很好的线性关系,相关系数为0.9997。检测限为0.08mg/mL;相对标准偏差为0.48%;加标回收率为100.3%。该方法快速、简便、准确,适合从复杂体系中快速检测白坚木皮醇的含量。     

Determination of Brassinolide Analogs by High-Performance Liquid Chromatography with Evaporative Light Scattering Detection

An efficient method based on high-performance liquid chromatography with evaporative light scattering detection was developed for the separation and determination of four brassinolide analogs [24-epibrassinolide, (22S, 23S)-24-epibrassinolide, 28-homobrassinolide, and (22S, 23S)-28-epihomobrassinolide] without prior derivatization. The optimized analysis was carried out on a C₁₈ reversed-phase column (150 mm × 4.60 mm, 3 µm) at 30°C using isocratic elution of acetonitrile and water (38:62, v/v). The drift tube temperature of the detector was 60°C and the auxiliary gas (nitrogen) pressure was 360 kPa. The regression equations revealed linear relationships (R² = 0.9984–0.9994) within the test ranges. The limits of detection and quantification were in the ranges of 0.12 to 0.17 µg and 0.24 to 0.33 µg, respectively. The fully validated method was applied to quantify the active ingredient content in technical material and formulations and provides an alternative approach for quality control.     

高效液相色谱-蒸发光散射检测法测定蛋黄卵磷脂的含量

建立了蛋黄磷脂中卵磷脂（即磷脂酰胆碱,PC)的高效液相色谱-蒸发光散射检测（HPLC-ELSD）的测定方法。以Nov a-Pak Silica 60A硅胶柱(3.9 mm i.d.×150 mm,4 μm)为分离柱,正己烷-异丙醇-3%冰醋酸水溶液(体积比为35∶65 ∶8)为流动相，等度洗脱,流速1.0 mL/min,柱温30 ℃。蒸发光散射检测器漂移管温度50 ℃,雾化气(空气)压力350 kPa。在上述条件下测得PC在0.16~1.61 g/L范围内线性关系良好(r2=0.9979),检测限为0.64 μg,方法的精密度为3.2%(n=5),回收率为98.2%~128.2%。将该方法用于实际样品的测定,获得了令人满意的结果。该方 法预处理简单,分析速度快,可用于蛋黄磷脂中卵磷脂的测定。     

甲基紫6B与核酸作用的共振光散射光谱及其分析应用

将三苯甲烷类碱性染料甲基紫6B用于核酸的共振光散射测定。在pH10.8的缓冲液中 ,核酸的加入导致甲基紫6B在386nm处共振光散射的增强 ,其强度与核酸的质量浓度呈线性关系 ,据此建立了一种测定核酸的共振光散射法。fsDNA与 yRNA的线性范围分别为0.083～1.0mg·L -1和0.076～0.8mg·L -1,检出限分别为82.6和75.3μg·L -1。将该法用于混合样品中核酸的测定 ,结果令人满意。     

微流蒸发光散射检测器的研制及评价

构建了适用于纳升级到微升级流量的毛细管分离体系的微流蒸发光散射检测器(μELSD),实现了其与毛细管液相色谱(eLC)的联用.对雾化器孔径和雾化毛细管内径、蒸发管内径和长度、光散射池尺寸、雾化毛细管位置和辅助载气流量等参数进行了优化.在最优条件下,微流蒸发光散射检测器检出限为直接进样葡萄糖1 ng(S/N＞ 10),线性范围0.01～1.0 μg,重复性好,峰面积RSD(n=6)为0.4％,峰高RSD(n=6)为0.3％.本检测器已成功应用cLC-μELSD平台,使用C18毛细管色谱柱(内径250 μm),0.1％甲酸铵溶液(pH 4.5)-甲醇(60∶40,V/V)为流动相,分离检测了3种常用甜味剂,表明本研究构建的系统可以应用于实际分离检测中,具有分析时间快、溶剂消耗量少、样品需求量小的优点.     

液相色谱/蒸发光散射测定转基因烟草提取液中的海藻糖

 采用乙二胺动态修饰硅胶柱分离、蒸发光散射检测器测定了转基因烟草提取液中的糖。 4种糖的峰面积标准曲线在 10 0mg/L～ 15 0 0mg/L范围内均具有良好的线性关系。所建立的方法对果糖、葡萄糖、蔗糖、海藻糖的检测下限分别为 10mg/L ,2 0mg/L ,10mg/L和 10mg/L。     

高效液相色谱－蒸发光散射法测定液态乳中乳果糖含量

液态乳中乳糖和乳果糖是同分异构体,因保留特性相似,成为色谱法分离检测乳果糖的难点。目前,虽有多种液相色谱检测乳果糖的报道,但方法在前处理的简便性、色谱柱的适用性及分离效果的稳定性等方面存在不足。该研究建立了高效液相色谱－蒸发光散射（HPLC－ELSD）检测液态乳中乳果糖的方法。采用0.4 mol/L醋酸铵（pH 3.8）沉降蛋白,氨基色谱柱分离,蒸发光散射检测器检测。液态乳中乳果糖与乳糖得到了良好的分离,在1.0～100 mg/L范围内线性关系良好（r2 = 0.998 0）,检出限为15 mg/L,定量下限为50 mg/L,回收率为85.1%～110%,相对标准偏差（RSD）不大于7.5%。该方法操作简单,可在8 min内完成检测,结果重复性好、准确度高,满足液态乳中乳果糖的日常检测要求。     

共振光散射法测定复方氨基酸注射液中色氨酸的含量

在pH1.98时,色氨酸和氯金酸发生氧化还原反应生成金纳米粒子。用扫描电镜、紫外-可见吸收光谱和荧光光谱对所生成的金纳米粒子进行了表征,并通过在普通荧光光度计上测定所生成的金纳米粒子的光散射信号,建立了定量检测色氨酸含量的方法。方法的线性范围为0.21～60.0μmol/L;检出限为0.02μmol/L。甘氨酸等10余种无还原性的氨基酸对体系不产生干扰。将所建立的方法用于复方氨基酸注射液中色胺酸的测定,相对误差小于5.7%;回收率在96.3%～104.6%之间。     

清开灵注射液HPLC/ELSD指纹图谱建立及质量相关性研究

运用高效液相色谱／蒸发光散射检测器(HPLC／ELSD)建立了复方清开灵注射液的指纹图谱。对其中7种有效成分进行了定量测定,方法学考察结果良好;通过指纹图谱相似度评价软件,对10批清开灵注射液的HPLC／ELSD指纹图谱进行了相似度计算,结果表明：10批样品相似度很好。该方法为中药质量控制提供了一种可以同时实现整体定性、指标成分定量且简便易行的方法模式。     

Analysis of Lipid Classes by HPLC with the Evaporative Light Scattering Detector

Abstract

The evaporative light scattering detector enables the detection and quantitation of all relatively non-volatile lipids. The mixtures of polar and non-polar lipids were separated in one run, in 20 to 25 minutes on Silica Si-100 columns, using consecutive gradients of pentane to diethylether, to chloroform, to methanol containing a large concentration of ammonia.

The flexibility of the method is illustrated by the change in elution patterns following the treatment of the packing material by ammonia. For example, the elution order of phosphatidyl inositol and phosphatidyl choline is reversed and the separation of the former compound from phosphatidyl serine, which is generally difficult, is now accomplished readily.

The weak dependence of the detector sensitivity on the nature of the analytes permits an easy quantitation, as illustrated by the results of the analyses of lipid classes in blood serum, amniotic fluid, beef brain and other natural samples.

The method is particularly useful for the analysis of lecithin and sphingomyelin in the amniotic fluid. The ratio of the concentration of these two compounds is an indicator of lung maturity and could permit an early diagnosis of the respiratory stress syndrome of neonates.     

超高效液相色谱-蒸发光散射检测法测定蜂蜜中12种糖组分

建立了蜂蜜中果糖、葡萄糖、蔗糖、松二糖、麦芽酮糖、麦芽糖、曲二糖、异麦芽糖、吡喃葡糖基蔗糖、松三糖、蜜三糖和麦芽三糖含量的超高效液相色谱－蒸发光散射测定方法。试样经去离子水溶解,乙腈定容,用0.22 μm滤膜过滤后,采用Amide色谱柱分离,蒸发光散射检测器检测,外标法定量。在优化实验条件下,12种糖得到良好分离,线性相关系数为0.997 7～0.999 8,果糖和葡萄糖的检测结果与示差折光检测法无显著性差异,其余10种糖的平均回收率为90.0 %～105 %,相对标准偏差为0.70%～5.8%。该方法灵敏度高,准确度高,重复性好,适用于蜂蜜中多种糖组分的同时定量分析。用于72批不同蜜种蜂蜜样品中糖组分的检测,发现中国主要蜜源蜂蜜中普遍含有松二糖、麦芽酮糖、麦芽糖等糖组分。该方法和检测数据可为蜂蜜品质和质量评价提供重要支撑。     

二醇基柱高效液相色谱-蒸发光散射检测法测定饮料中的糖

采用二醇基柱分离、蒸发光散射检测法测定了饮料中的糖。比较了乙腈-水、二氯甲烷-甲醇两种流动相分析糖的特点。采用二氯甲烷-甲醇为流动相,果糖、葡萄糖、蔗糖、麦芽糖和棉子糖的峰面积与绝对进样量的标准曲线在绝对进样量为1.6μg-40μg时均具有良好的线性关系。该方法对上述5种糖的检测限分别为0.20μg,0.16μg,0.16μg,0.20μg和0.20μg。     

高效液相色谱-蒸发光散射检测法测定草石蚕根茎中的水苏糖

应用高效液相色谱 蒸发光散射检测法建立了测定草石蚕植物根茎中水苏糖含量的新方法 ,并设计和讨论了 2种从草石蚕根茎干粉中提取水苏糖的工艺方法。采用BondapakNH2 色谱柱 (3 0 0mm× 3 .9mmi.d .) ,流动相为甲醇 水 (80∶2 0 ,V V) ,流速 1 .0mL min,柱温为室温 ;蒸发光散射检测器漂移管温度 40℃ ,载气N2 流速 4.0L min。在上述条件下测得水苏糖在 1 .0 2～ 1 2 .2 2 μg范围内线性关系良好 (r=0 9995 ) ,检出限达到 0 .1 0 μg,平均加样回收率为 91 .6%。 2种不同提取方法的测定结果 :水苏糖含量分别为 2 9.8%和 2 5 .2 % ,纯度为 63 .76%和 88.3 5 %。该方法简便快捷 ,重现性和准确度良好 ,结果准确可靠 ,为实际样品的测定提供了科学依据。     

Performance Evaluation of Charged Aerosol and Evaporative Light Scattering Detection for the Determination of Ginsenosides by LC

A sensitive LC-CAD method was developed for simultaneous determination of seven major triterpenoid saponins, namely ginsenosides Rg₁, Re, Rb₁, Rc, Rb₂, Rb₃ and Rd in Panax ginseng C. A. Meyer, a commonly used traditional Chinese medicine. This CAD method was evaluated in sensitivity, linearity and reproducibility compared to ELSD and UV. It was found the developed method has improved sensitivity, linearity and reproducibility compared to ELSD. This method was successfully applied to analyze the ginsenosides in ten samples of Panax ginseng. The validation results indicated that the improved method can be utilized as another approach for quality control of P. ginseng.     

复方丹参提取物高效液相色谱-紫外-蒸发光散射检测指纹图谱的建立

采用紫外/蒸发光散射检测器(UV和ELSD)串联检测技术,建立了复方丹参提取物HPLC/UV/ELSD指纹图谱。运用指纹图谱相似度评价软件,对14批复方丹参提取物HPLC/UV/ELSD指纹图谱进行相似度计算,结果相似度良好。该指纹图谱能同时反映复方丹参提取物中丹参和三七的主要化学组分特征,可有效评价复方丹参提取物的质量稳定性。     

反相高效液相色谱-蒸发光散射检测法测定安宫牛黄胶囊中的胆酸

应用反相高效液相色谱-蒸发光散射检测法对安宫牛黄胶囊中的胆酸含量进行了测定。色谱柱用JASCO C18柱(250 mm×4.6 mm i.d.,5 μm),流动相为甲醇-0.1%(体积分数)醋酸水溶液(体积比为9∶1),流速1.0 mL/min,柱温为室温;蒸发光散射检测器漂移管温度40 ℃,载气（N2)流速4.0 L/min。在上述条件下测得胆酸的进样量为0.50-5.02 μg时线性关系良好(r=0.999?3),最低检测限达到0.05 μg,平均加样回收率为97.1%。该方法快速简捷,精密度高,重现     

毛细管电泳-电化学发光/电化学检测法同时测定维生素B_1和B_6

建立了毛细管电泳-电化学发光/电化学检测(CE-ECL/EC)法同时测定维生素B1(VB1)和维生素B6(VB6)的新方法。在碱性条件下对VB1进行水解,可增强其电化学发光信号,并采用序贯均匀设计对毛细管电泳分离条件进行优化,测定VB1的电化学发光信号和VB6的电化学信号。VB1和VB6能在5min内得到良好的分离。电化学发光强度与VB1浓度在5.0~5 000.0μg/mL范围内具有良好的线性关系(r=0.997),检测限(S/N=3)为2.7μg/mL;电流强度与VB6浓度在10.0~1 000.0μg/mL范围内具有良好的线性关系(r=0.998),检测限(S/N=3)为6.8μg/mL。VB1和VB6的加标回收率范围为96.0%~100.0%,相对标准偏差为1.4%~6.7%。用建立的方法对复合VB片中的VB1和VB6进行测定,结果较好。