毛细管柱气相色谱法测定食品中的防腐剂苯甲酸

目的：研究毛细管柱气相色谱法测定食品中的防腐剂苯甲酸的方法。方法：采用适当的样品处理方法，应用中等极性的1701毛细管柱取代玻璃柱检测食品样品中的防腐剂苯甲酸。结果：在最佳分析条件下，样品中苯甲酸在0．005-0．10mg／ml范围内有良好线性关系（r=0．9998），回收率97．3％-98．0％，精密度1．6％-1．9％。结论：相对于国家标准方法推荐的填充柱，毛细管柱的柱效高，通用性好，结果更易重复，是食品中苯甲酸检测的另一个选择。     

毛细管柱测定工作场所1,2-二氯乙烷和三氯丙烷

目的采用毛细管柱气相色谱法测定工作场所中的1,2-二氯乙烷和三氯丙烷含量。方法气相色谱法,用活性碳管吸附,二硫化碳溶液解吸,FID检测器分析。结果1,2-二氯乙烷在0—1256肛∥ml;三氯丙烷在0-694μg／ml范围内线性良好,当采样体积为4．5L时,最低检出浓度为1,2-二氯乙烷0．2mg／m3,三氯丙烷0．5mg／m3标准溶液平行测定的RSD〈2％,加标回收率为1,2-二氯乙烷96．8％～95．5％;三氯丙烷95．6％～95．0％。结论采用FFAP毛细管柱分离效果优于填充柱。     

复合食品包装袋中二氨基甲苯的毛细管柱气相色谱方法的研究

目的：建立了毛细管柱气相色谱法测定复合食品包装袋中二氨基甲苯的含量。方法：样品用沸水浸提，在碱性条件下甲苯萃取，七氟丁酸酐衍生后用HP-5石英毛细管柱分离，电子捕获检测器检测。结果：二氨基甲苯的浓度在0．0005～0．008mg／L范围内呈良好的线性关系，线性方程为：Y：2799＋45628689X（r=0．9997）。最低检测浓度为0．0005mg／L，加标回收率在93．0％-104．3％，相对标准偏差在3．4％-7．7％。结论：方法快速、灵敏、准确，可满足复合食品包装袋中二氨基甲苯的测定需要。     

毛细管气相色谱法测定绍兴黄酒中挥发性物质

目的：建立毛细管气相色谱法测定绍兴黄酒中挥发性物质的方法。方法：酒样经蒸馏后，用DB—FFAP毛细管柱分离，FID检测器测定。结果：绍兴黄酒中挥发性物质（除乙醇外）乙醛、乙酸乙酯、乳酸乙酯、甲醇、正丙醇、异丁醇、异戊醇、β-苯乙醇、乙酸定量准确，加标回收率为88％～99．5％，相对标准偏差为3．8％～8．2％，在0．500mg／L之间的线性关系良好，最低检出限在0．5～1．5mg／L之间。结论：方法可一次同时进行绍兴黄酒中多组分挥发成分的定性、定量，检测灵敏度能满足要求，精密度较好，准确性较高。     

离子色谱法测定血液透析浓缩液中K+、Na+、Ca2+、Mg2+

目的：本文应用离子色谱法测定血液透析浓缩液中K^＋、Na^＋、Ca^2＋、Mg^2＋ 含量。方法：选用CS12A阳离子分析柱，CG12A保护柱，20mmoL／L甲基磺酸淋洗液，流速为1．00mL／min，电导检测器。将样品溶液稀释后，经0.45μm滤膜过滤后直接进样测定。结果：本方法相关性好（r=0．9999），精密度高（R5D％〈6.00），样品加标平均回收率为96．5％～103.2％，各阳离子的最低检出限为Na^＋：0．01mg／L、K^＋：0．02mg／L、Mg^2＋：0.05mg／L、Ca^2＋：0．05mg／L。结论：该方法操作简便、准确、灵敏，应用范围广，具有较高的实用价值。     

直接进样毛细管柱气相色谱法快速测定全血中乙醇含量

目的：建立一种直接进样毛细管柱气相色谱法快速测定全血中乙醇含量的方法。方法：用内标法，5％偏磷酸作沉淀剂，血样离心后，样品直接进入毛细管柱气相色谱测定乙醇的含量。计算全血中的乙醇含量，评价本方法的准确度、精密度、线性范围。结果：在该色谱条件下能完全分离乙醛、甲醇、乙醇、丙酮、异丙醇、叔丁醇、正丙醇、正戊醇和异戊醇；血中乙醇浓度线性方程为Y=1．639X-0．0103，r=0．9965，线性范围为10～100mg／100ml，最低检出限为0．1mg／100ml，日内精密度≤3．0％，日间精密度≤7％，回收率为101．7％。结论：本法具有快速、准确、灵敏度高、操作简便等优点，可应用于酒精中毒的诊断。     

毛细管柱气相色谱法同时测定白酒中12种有机物质

目的：建立毛细管柱气相色谱法同时测定白酒中醇类、酯类、醛类12种有机物质的方法。方法：用AT酒柱分离，FID检测器检测，同时测定白酒中多种成分。结果：该法分离效果好，检出限在0．5—1．5mg／100ml之间，相关系数0．9999，回收率为90．4％～107．9％，RSD在0．90％～1．68％之间。结论：方法操作简便、灵敏、快速、准确。     

反相梯度色谱法测定饮料中安赛蜜、糖精钠、阿斯巴甜

目的 研究反相梯度液相色谱法测定饮料中安赛蜜、糖精钠、阿斯巴甜含量。方法采用C18 4．6mm×250mm5μm为分析柱，以CH3CN：（NH4）2SO4（5：95）为流动相，流速：1．00ml／min，波长214nm，应用梯度液相色谱技术对安赛蜜、糖精钠、阿斯甜进行分析测定。结果 在1．0～20．0mg／L范围内有良好线性关系（1=0．9999），平均回收率为88．0％～101．5％。结论 该方法具有良好线性关系、精密度好，结果准确，实用性强。     

反相梯度液相色谱法测定食品中阿斯巴甜糖精钠安赛蜜

[目的]研究反相梯度液相色谱法测定食品中阿斯巴甜、糖精钠和安赛蜜含量。[方法]采用C18 5μm 3．0mm×250mm窄径柱为分析柱,以CH3CN：（NH4）2SO4为流动相,流速：0．60ml／min,波长214nm实验,应用梯度液相色谱技术对阿斯巴甜、糖精钠、安赛蜜进行分析测定。[结果]在1．0～20．0mg／L范围内有良好线性关系（r=0．9999）,平均回收率为92．0％～101．5％。[结论]实验表明该方法具有良好的线性关系,精密度好,结果准确,实用性强。     

溶解沉淀-气相色谱法测定聚氯乙烯食品保鲜膜中增塑剂己二酸二(2-乙基)己酯(DEHA)含量

目的：研究开发了溶解沉淀前处理技术结合毛细管气相色谱法测定聚氯乙烯食品保鲜膜中己二酸二（2-乙基）己酯（DEHA）含量。方法：采用四氢呋喃作为溶剂，甲醇作为沉淀剂，可有效的将DEHA从聚氯乙烯薄膜中分离出来，然后采用非极性DB-1MS毛细管气相色谱柱进行分离，氢火焰离子化检测器检测，以气相色谱质谱进行确证。结果：DEHA在1．0～100．0mg／L范围内线性关系良好，相关系数o．999，方法回收率在87．8％-99．1％之间，相对标准偏差小于5％，检测限为0．1mg／L。结论：该方法操作简便，测定结果准确可靠，适合聚氯乙烯保鲜膜中DEHA含量的测定。     

Gamma-linolenic acid, arachidonic acid, and eicosapentaenoic acid as potential anticancer drugs

Several in vitro studies and limited in vivo investigations showed that some cis-unsaturated fatty acids (c-UFAs) such as gamma-linolenic acid, arachidonic acid, and eicosapentaenoic acid have selective tumoricidal actions. This cytotoxic action of c-UFAs is produced by augmentation of free-radical generation and lipid peroxidation in tumor cells but not in normal cells. Moreover, lymphokines such as interferon and tumor necrosis factor seem to produce their antitumor effects by inducing the release of c-UFAs from the cell-membrane lipid pool and free-radical generation, and several anticancer drugs, especially doxorubicin and vincristine, have the capacity to augment free-radical generation and promote lipid peroxidation. Tumor cells are known to contain low amounts of c-UFAs, have decreased capacity to generate free radicals and lipid peroxides, and are highly susceptible to free radical-induced cytotoxicity compared with normal cells. In addition, c-UFAs and their products can modulate the immune response, augment the respiratory burst of neutrophils and free-radical generation by macrophages, and modify genetic damage induced by mutagens and carcinogens. These evidences, coupled with the observation that the cancer incidence is low in Eskimos on traditionally high-c-UFA diets, suggests that c-UFAs can be exploited as possible anticancer agents either alone or in combination with lymphokines and cancer chemotherapy.     

复方苯甲酸酊剂中苯甲酸及水杨酸的含量检测

目的:探索复方苯甲酸酊剂两种主要成分稳定有效的含量测定方法.方法:用中和法测定两酸的总量,用紫外分光光度法测定水杨酸的含量,从总量中减去水杨酸的含量即为苯甲酸的含量.结果:回收实验苯甲酸平均回收率为100.13%,RSD为0.73%;水杨酸平均回收率为99.95%,RSD为0.23%.结论:结合使用中和法和紫外分光光度法能较好地同时检测复方苯甲酸酊剂中两种主要成分的准确含量.     

Docosahexaenoic acid and arachidonic acid prevent essential fatty acid deficiency and hepatic steatosis

Objectives: Essential fatty acids are important for growth, development, and physiologic function. α‐Linolenic acid and linoleic acid are the precursors of docosahexaenoic and arachidonic acid, respectively, and have traditionally been considered the essential fatty acids. However, the authors hypothesized that docosahexaenoic acid and arachidonic acid can function as the essential fatty acids. Methods: Using a murine model of essential fatty acid deficiency and consequent hepatic steatosis, the authors provided mice with varying amounts of docosahexaenoic and arachidonic acids to determine whether exclusive supplementation of docosahexaenoic and arachidonic acids could prevent essential fatty acid deficiency and inhibit or attenuate hepatic steatosis. Results: Mice supplemented with docosahexaenoic and arachidonic acids at 2.1% or 4.2% of their calories for 19 days had normal liver histology and no biochemical evidence of essential fatty acid deficiency, which persisted when observed after 9 weeks. Conclusion: Supplementation of sufficient amounts of docosahexaenoic and arachidonic acids alone without α‐linolenic and linoleic acids meets essential fatty acid requirements and prevents hepatic steatosis in a murine model.     

Docosahexaenoic acid and n-6 docosapentaenoic acid supplementation alter rat skeletal muscle fatty acid composition

Background  

Docosahexaenoic acid (22:6n-3, DHA) and n-6 docosapentaenoic acid (22:5n-6, DPAn-6) are highly unsaturated fatty acids (HUFA, ≥ 20 carbons, ≥ 3 double bonds) that differ by a single carbon-carbon double bond at the Δ19 position. Membrane 22:6n-3 may support skeletal muscle function through optimal ion pump activity of sarcoplasmic reticulum and electron transport in the mitochondria. Typically n-3 fatty acid deficient feeding trials utilize linoleic acid (18:2n-6, LA) as a comparison group, possibly introducing a lower level of HUFA in addition to n-3 fatty acid deficiency. The use of 22:5n-6 as a dietary control is ideal for determining specific requirements for 22:6n-3 in various physiological processes. The incorporation of dietary 22:5n-6 into rat skeletal muscles has not been demonstrated previously. A one generation, artificial rearing model was utilized to supply 22:6n-3 and/or 22:5n-6 to rats from d2 after birth to adulthood. An n-3 fatty acid deficient, artificial milk with 18:2n-6 was supplemented with 22:6n-3 and/or 22:5n-6 resulting in four artificially reared (AR) dietary groups; AR-LA, AR-DHA, AR-DPAn-6, AR-DHA+DPAn-6. A dam reared group (DAM) was included as an additional control. Animals were sacrificed at 15 wks and soleus, white gastrocnemius and red gastrocnemius muscles were collected for fatty acid analyses.