Separation of oligonucleotides by reversed-phase high performance liquid chromatography

The use of Reversed-Phase High Performance Liquid Chromatography (RP-HPLC) was investigated for the separation of oligonucleotides. By the gradient elution with the mobile phase of methanol, 0.1 M KH₂PO₄ and 0.02 M MaCl₂, the mixtures could be separated in a 250 mm × 4.6 mm I.D. column. The number of theoretical plates and resolution were compared belween this technique and Micellar Electrokinetic Capillary Chromatography (MECC). The charged nucleic acid constituents in the RP-HPLC were relatively better separated than in the MECC.     

Separation of surfactant mixtures and their homologs by high performance liquid chromatography

A technique for separating similar and diverse ionogenic mixtures into their individual homologs was studied by high performance liquid chromatography on an octadecyl-silica (TSK Gel LS-410) column. Conditions used for the separation were: column size, 6 mm id×200 mm; mobile phase, water/methanol (15:85, v/v) containing (a) 1.0 M sodium perchlorate and adjsting to pH 2.5 with phosphoric acid, (b) 0.1 M and pH 3.5; column temp., 50 C. By using 2 mobile phase conditions, various surfactant mixtures were separated into their individual homologs and simultaneously distinguished from each other, regardless of their ionogenic properties.     

Separation of α-tocopherol and its oxidation products by high performance liquid chromatography

A very sensitive high performance liquid chromatographic (HPLC) method was developed for the separation of α-tocopherol (α-T) and its five oxidation products: α-tocopheryl quinone (TQ), dimer (D), dihydroxy dimer (DHD), trimer (T) and 9-methoxy-α-tocopherone commonly called α-tocopheroxide (TO). The separation was achieved on a normal-phase silica-based column (Ultrasphere-Si), using a mobile phase of hexane/chloroform/isopropanol (95∶4.5∶0.5, v/v/v) at a flow rate of 0.4 ml/min, and the eluants were monitored simultaneously at their maximum absorptions using a variable-wavelength UV detector. The minmum detection limit is 0.01 μg for α-T, TQ and TO, 0.05 μg for DHD and D, and 0.1 μg for T/injection. This normal-phase method has the combined advantages of being very sensitive, fast and capable of separating all six compounds at the same time.     

Separation of tetra-, penta-, and hexaacyl triglycerides by high performance liquid chromatography

Synthetic triglycerides with more than three acyl groups were prepared by forming estolides from triglycerides containing one, two, or three monohydroxy fatty acyl moieties. These tetra-, penta-, and hexaacyl triglycerides were examined by high performance liquid chromatography (HPLC) and thin layer chromatography (TLC). HPLC separation by the number of acyl groups was obtained with both conventional phase and reverse phase columns. In all systems, triglycerides were eluted first, followed in sequence by tetra-, penta-, and hexaacyl triglycerides. Within each glyceride class, further separation occurred due to variations in chain length and degree of unsaturation among the component acids. TLC migration on silica gel was found to be a function of the number of acyl groups and the length of component acid chains. The mention of firm names or trade products does not imply that they are endorsed or recommended by the U.S. Department of Agriculture over other firms or similar products not mentioned.     

Separation of molecular species of ceramides as benzoyl andp-nitrobenzoyl derivatives by high performance liquid chromatography

Ceramides were subjected to direct separation and structural analysis by high performance liquid chromatography after derivatization with benzoyl andp-nitrobenzoyl chloride. The structures of benzoyl andp-nitrobenzoyl derivatives of a representative ceramide, N-heptadecanoyl D-sphingosine, were fully characterized by mass spectrometry. Excellent separation of molecular species of ceramides was achieved with a 10-μ LiChrosorb RP18 column by isocratic elution. Both the acyl group and the long-chain base moiety were separated on this reverse-phase column. The method has been used to determine quantitatively molecular species of nonhydroxy ceramides derived from bovine brain and egg yolk. Comparison of gas liquid chromatographic and high performance liquid chromatographic assays of intact ceramides was made. Presented at the International Society of Fat/ American Oil Chemists' Society in New York, April 29, 1980.     

高效液相色谱法测定卷柏中的穗花杉双黄酮

用反相高效液相色谱法测定卷柏提取物中的穗花杉双黄酮。结果表明：穗花杉双黄酮在质量浓度为41.2mg／L～206mg／L时，峰面积Y与其质量浓度X的线性关系良好，回归方程为Y=547．028X 15．4895(r=0.9999)，最低检测限为2．0μg/L；穗花杉双黄酮的平均回收率为99．42％(n=3)，相对标准偏差RSD为0．79％；连续进样、日内进样和日间进样所得检测结果的RSD分别为0．12％、0．11％和0．11％。     

高效液相色谱分析乙酰甲胺磷原药

采用反相高效液相色谱法测定乙酰甲胺磷原药中的有效成分,以甲醇∶水=15∶85(体积比)作为流动相,在波长为215 nm条件下检测乙酰甲胺磷原药有效成分含量,本方法的线性相关系数为0.9999,标准偏差为0.21,变异系数为0.22%,平均回收率为99.75%。     

Separation and purification of lecithins by high pressure liquid chromatography

Ten different synthetic lecithins have been analyzed by reverse-phase high pressure liquid chromatography. An empirical lecithin “carbon number” that depends on the total number of carbons and double bonds in the fatty acyl chains in a useful index in predicting retention volumes of lecithins on a nonpolar octadecyl fatty acid column. Commercial egg lecithin is separated into its components by this technique.     

Determination of ascorbyl palmitate by high performance liquid chromatography

An HPLC method for the determination of ascorbyl palmitate in vegetable oil and lard has been developed. Chromatographic conditions consist of a diamine column, a mobile phase of 70:30 (v/v) methanol:0.02M monobasic potassium phosphate buffer, pH 3.5, and UV detection. Samples were extracted with methanol. An overall average recovery value of 96.7% was obtained for ascorbyl palmitate in five representative vegetable oils and lard.     

Determination of TBA number by high performance liquid chromatography

A high performance liquid chromatographic (HPLC) method for the quantitation of malonaldehyde in aqueous distillates was developed. Compared with the standard TBA test, the HPLC method was faster, and less affected by side feactions. A total of 5 min was necessary to assay each distillate and only malonaldehyde was detected. The standard curves were reproducible and standards were stable for up to 6 days. The HPLC method could detect malonaldehyde levels ranging from 1×10⁻¹¹ to 4×10⁻¹¹ mol/10μL and either peak height or peak area could be used to quantitate the malonaldehyde concentration. The coefficient of determination between absorbance values determined by the TBA test and peak heights determined by HPLC was 0.946. Twenty-one freeze-dried chicken samples with TBA numbers ranging from 3.93 to 16.6 were used for this correlation.     

反相高效液相色谱法测定苯扎贝特的含量

研究了采用反相高效液相色谱测定苯扎贝特含量的方法 ,以磷酸盐缓冲液 (0 0 1mol/L的磷酸二氢钾用磷酸调节pH至 3 8) 甲醇 (4∶6 )为流动相 ,采用HypersilC18柱 (5 μm ,4 6mm× 15 0mm) ,检测波长为 2 30nm ,苯扎贝特在 0 0 114～0 114mg/mL范围内线性相关 ,回归方程为 :A =1 0 5× 10 4c(mg/mL) +2 70× 10 2 ,r =0 9997,此法简便、快速、结果准确可靠     

抗氧化剂168的高效液相色谱法分析

探讨了抗氧化剂168的高效液相色谱分析方法,采用甲醇/乙酸乙酯作流动相。实验表明,在0.2～0.8 mg/mL具有较好的线性,平行测定5组数据,其标准偏差为0.011,质量回收率99.7%～102.7%。     

高效液相色谱法测定维生素K_4的含量

采用YWG-C18柱,以甲醇∶水=85∶15(体积比)为流动相,流速为0.5 mL/min,以285 nm为检测波长,建立维生素K4(化学名为2-甲基-1,4萘二酚双醋酸酯)的高效液相色谱法。该方法在2~10μg范围内线性关系良好,相关系数为0.999 8。回收率99.15%~100.8%,相对标准偏差为0.66%。该方法操作简单,分析速度快,结果准确,适用于维生素K的产品检验。     

高效液相色谱分析敌百虫原药

采用高效液相色谱法测定敌百虫原药中的有效成分,以乙腈:水(10:90,v/v)作流动相,在pH=2.90,波长为210nm,流速1mL/min的条件下,能有效地将敌百虫中所有杂质分离.此方法的线性相关系数为0.9999,标准偏差为0.25,变异系数为0.27%,平均回收率为99.76%.     

Triglyceride separation by reverse phase high performance liquid chromatography

Rapid separations of triglycerides by chain length and degree of unsaturation were made by high performance liquid chromatography (HPLC) on a C-18 μ-Bondapak column with acetonitrile-acetone solvent mixtures. For saturated triglycerides, a linear relationship was observed between the carbon number and the log of the retention volume. Each double bond present in the triglyceride decreased the retention volume to approximately that of a saturated triglyceride with two carbon atoms less. Correlations of the fatty acid composition, as determined by gas liquid chromatography (GLC) with the HPLC data, provides much additional insight about triglyceride composition. To calculate triglyceride compositions, an internal standard tripentadecanoin was added to collected fractions before analysis by GLC.     

Separation ofCis andTrans isomers by reverse phase high pressure liquid chromatography

A reverse phase high pressure liquid chromatography procedure was devised for the analytical or preparative separation of geometric isomers of dodecenyl acetates, tetradecenyl acetates, hexadecenyl acetates, tridecadienyl acetates, and methyl oleate and elaidate. Use of μ Bondapak C-18 permitted the separation of these isomers. ARS, USDA.     

高效液相色谱法测定剑麻皂苷元的含量

以乙腈-水(90∶10)溶液为流动相,检测波长为225 nm,建立了高效液相色谱法测定剑麻皂苷元的方法。结果表明,剑麻皂苷元在4.8²4μg范围内线性相关,回归方程:Y=6 186.312 5X-14 660.1,R2=0.985 48。精密度实验RSD为0.013%,稳定性实验说明在11 h内稳定,重复性实验RSD为0.062%,加标回收率实验平均回收率为96.2%,样品中剑麻皂苷元的含量为0.571 2 mg/g,此方法操作简便、准确、可靠,可为剑麻皂苷元的质量检测提供依据。     

高效液相色谱法定量测定去屑剂双吡啶硫酮

建立了高效液相色谱测定去屑剂双吡啶硫酮的方法.在XDB-C18(5 um,4.6 mm×150 mm)色谱柱上,以V(甲醇):V(超纯水)=30:70为流动相,VWD检测器的检测波长设为235 nm,流速为1.0 mL/min,柱温为35℃.方法检出限为0.05 mg/L,双吡啶硫酮在0～400 mg/L呈良好的线性关系,相关系数为0.995 3,香波样品加标回收率为93.75%～97.50%,相对标准偏差为0.28%～0.35%.     

高效液相色谱法测定大米38中抑虫肼的残留量

建立了高效液相色谱法测定大米中抑虫肼残留量的方法。样品采用丙酮-水提取、二氯甲烷萃取、硅胶和中性氧化铝柱净化后,用Nuc leosil 100-5 C18柱(250 mm×4.6 mm i.d.,5μm)分离,以乙腈-水(体积比55∶45)作流动相,流速1.0mL.m in-1,于234nm波长处检测。结果表明,样品的加标平均回收率为93.5%~81.2%,相对标准偏差为2.03%~5.50%,样品测定低限(LOQ)为0.025mg.kg-1。该方法具有简便、快捷、灵敏、重现性好。