吡虫啉在蔬菜中残留量高效液相色谱测定方法

建立了用高效液相色谱法测定出口蔬菜中吡虫啉农药残留量的方法。试样用酸性乙腈提取,C18柱净化,乙酸乙酯洗脱,反相高效液相色谱-紫外检测器测定,检测波长为270nm。方法的最低检测限为0.05mg/kg,0.1～0.5mg/kg水平添加回收率的范围是86.67%～100.33%,相对标准偏差为3.19%～9.95%。     

三唑嘧啶酮原药的高效液相色谱分析

采用高效液相色谱法,使用C18(ODS)分离柱、甲醇∶水为流动相和二极管阵列检测器,用外标法测定三唑嘧啶酮原药中有效成分的含量。方法的标准偏差为0.22%,变异系数为0.23%,线性相关系数为0.999 7,回收率为98.49%～100.5%。     

40%毒死蜱微乳剂的高效液相色谱法分析

采用ODS–C18反相色谱柱,用高效液相色谱法测定40%毒死蜱微乳剂制剂含量。方法的相关系数为0.9998,标准偏差为0.0242,变异系数为0.06%,平均回收率为98.6%。     

Eicosapentaenoic acid (20∶5n-3) from the marine microalgaPhaeodactylum tricornutum

Eicosapentaenoic acid (EPA, 20∶5n-3) was obtained from the marine microalgaePhaeodactylum tricornutum by a three-step process: fatty acid extraction by direct saponification of biomass, polyunsaturated fatty acid (PUFA) concentration by formation of urea inclusion compounds, and EPA isolation by semipreparative high-performance liquid chromatography (HPLC). Alternatively, EPA was obtained by a similar two-step process without the PUFA concentration step by the urea method. Direct saponification of biomass was carried out with two solvents that contained KOH for lipid saponification. An increase in yield was obtained because the problems associated with emulsion formation were avoided by separating the biomass from the soap solution before adding hexane for extraction of insaponifiables. The most efficient solvent, ethanol (96%) at 60°C for 1 h, extracted 98.3% of EPA. PUFA were concentrated by the urea method with a urea/fatty acid ratio of 4∶1 at a crystallization temperature of 28°C and by using methanol and ethanol as urea solvents. An EPA concentration ratio of 1.73 (55.2∶31.9) and a recover yield of 78.6% were obtained with methanol as the urea solvent. This PUFA concentrate was used to obtain 93.4% pure EPA by semipreparative HPLC with a reverse-phase, C₁₈, 10 mm i.d.×25-cm column and methanol/water (1% acetic acid), 80∶20 w/w, as the mobile phase. Eighty-five percent of EPA loaded was recovered, and 65.7% of EPA present inP. tricornutum biomass was recovered in highly pure form by this three-step downstream process. Alternatively, 93.6% pure EPA was isolated from the fatty acid extract (without the PUFA concentration step) with 100% EPA recovery yield. This two-step process increases the overall EPA yield to 98.3%, but it is only possible to obtain 20% as much EPA as that obtained by three-step downstream processing.     

久效磷原药的液相色谱分析

本文采用液相色谱法，选择Ｃ１８色谱柱，甲醇水为流动相，２４０纳米检测，外标法宣，标准偏差０．３５，变异系数０．４５％，回收率平均值９９．８７％。     

乙醛酸和草酸的高效液相色谱分析

采用高效液相色谱法测定了草酸电合成乙醛酸中乙醛酸和草酸的含量,方法简便,成本低廉,效果良好。色谱柱为VP-ODS(150 mm×4.6 mm),流动相为稀磷酸水溶液(pH=2.7),流速为0.5 mL/min,柱温40℃,检测波长为212 nm。探讨了pH值及其它条件对色谱分离的影响。乙醛酸的线性方程为:Y=1.226×102X-7.053×102,线性相关系数R=0.999 6,相对标准偏差为1.5%,检出限为3.0×10-9g;草酸的线性方程为:Y=1.670×103X-5.563×104,线性相关系数R=0.999 9,相对标准偏差为0.8%,检出限为2.3×10-10g。     

亚苄基海因水解制备苯丙酮酸过程的色-质联用分析

针对亚苄基海因水解体系建立了一种高效实用的液相色谱分析方法,为生产工艺控制提供了依据,并应用液-质联用技术对此体系中的未知副产物进行了初步检测。具体液相色谱条件为:流动相:乙腈 -5mmol·L-1乙酸盐缓冲液(用醋酸调pH4 5 ),流速 0 5mL·L-1;梯度洗脱;色谱柱:AgilentEclipseXDB-C8, 5μm, 4 6×150mm, 20℃;二极管阵列检测器,检测波长: 204nm。色-质联用中质谱条件为:ESI离子源,负离子模式;气帘气流量1 03×105 Pa,电喷雾电压-4 200V,离子源温度 500℃,辅助雾化气 1 37×105 Pa,干燥气 4 13×105 Pa,相对分子质量检测范围:m/z40~600。液相色谱法测定亚苄基海因和苯丙酮酸的线性相关系数为0 999 05和0 999 86,亚苄基海因和苯丙酮酸的平均回收率为 101 45 %和 97 23 %,相对标准偏差为 1 002%和0 833 8%。精密度以相对标准偏差来表示,分别为0 591 9 % 和0 648 2 %。结果表明,该液相色谱分析方法简便、快速,结果准确,可以用于苯丙酮酸生产的质量控制。     

30%毒·灭乳油(顽虫净)高效液相色谱分析

采用反相高效液相色谱法 ,以甲醇 +水 =70 +30 (v/v)为流动相 ,用紫外检测器对毒死蜱·灭多威乳油进行分离和测定。结果表明 :毒死蜱和灭多威含量测定的精密度标准偏差分别为0 0 7和 0 0 5 ;变异系数分别为 0 35 %和 0 5 0 % ,回收率分别为 98 99%～ 10 1 0 2 %和 99 6 4%～10 1 95 % ,线性相关系数分别为 0 9999和 0 9996。     

高效液相色谱法在氟铃脲标准样品制备中的应用研究

标准样品是农残分析巾的必要条件。应用高效液相色谱法进行氟铃脲的纯化、制得氟铃脲标准样品，用DELTA PAK C18柱，以乙腈-水(68：32)为流动相，在波长254nm，室温下进行了保留值定性、定值分析、均匀性及稳定性考察，效果良好。     

高效液相色谱法分析混合甲基萘

建立了甲基萘的高效液相色谱分析方法，确定了紫外检测器波长、流动相及其组成等实验条件。结果表明：用高效液相色谱法分析混合甲基萘，α-甲基萘和β-甲基萘可以得到有效分离。