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.     

酱腌菜中苯甲酸、山梨酸含量的检测结果分析

目的:了解我市酱腌菜中防腐剂的使用情况,加强食品添加剂的监测。方法:按GB/T5009.29-2003食品中苯甲酸、山梨酸的测定方法进行定量测定。结果:以GB2760-2007酱腌菜中苯甲酸,山梨酸标准进行评价,检出率为65%,超标率为30%。结论:我市酱腌菜中防腐剂的使用较为广泛,有的厂家超量使用防腐剂情况令人担忧,今后更需加强监督监测,以确保广大消费者的健康和安全。     

高效液相色谱法同时测定食品中的苯甲酸、山梨酸、脱氢乙酸及糖精钠

目的:采用0.3%盐酸乙醇提取,低温下沉淀蛋白质,水定容离心过滤的前处理方法,高效液相色谱法同时测定苯甲酸、山梨酸、脱氢乙酸及糖精钠。方法:色谱柱DIONEX Acclaim120 C18(4.6×250 mm,5μm),甲醇-0.02 mol/L磷酸氢二钾溶液pH 7.0(10∶90)为流动相,流速:1.0 ml/min,检测波长:230 nm(苯甲酸、山梨酸、糖精钠)和293 nm(脱氢乙酸)。结果:苯甲酸、山梨酸、脱氢乙酸及糖精钠在0.1μg/ml～20μg/ml浓度范围内线性关系良好(r>0.9999),检出限小于0.4 mg/kg,其加标回收率在92.6%～105.4%之间,重复测定的RSD≤2.0%。结论:该方法操作简单,灵敏度高,准确性好,可应用于大批量样品的快速检测。     

液液萃取-超声辅助衍生化气相色谱法同时测定水中二氯乙酸、三氯乙酸和2.4 - 滴

目的 建立生活饮用水中二氯乙酸、三氯乙酸和2.4 - 滴的液液萃取 - 衍生气相色谱法。方法 水中被测物用甲基叔丁醚萃取,然后在50℃恒温超声下,硫酸 - 甲醇衍生,衍生产物采用DB - 5毛细管柱（30 m×320 μm, 0.25 μm）程序升温分离、电子捕获检测器检测,内标法定量。结果 方法的线性范围为0.003 mg/L～0.400 mg/L,检出限为0.0004mg/L～0.0030 mg/L,回收率为83.4%～109.7%,相对标准偏差为7.63%～9.31%。结论 本法快速,重现性好,灵敏度高,可用于饮用水中二氯乙酸、三氯乙酸和2.4 - 滴的同时测定。     

HPLC法测定油浸食品中的苯甲酸、山梨酸含量

目的建立油浸食品中苯甲酸、山梨酸等防腐剂的高效液相色谱测定方法。方法采用10%的乙醇-磷酸盐混合溶液萃取,Eclipse XDB-C18柱分离,流动相:甲醇+乙酸铵(0.02 mol/L)溶液=6+94。结果苯甲酸的线性范围0～160μg/ml,r=0.999 8,最低检出浓度为0.90 mg/kg,加标回收率在96.9%～101.5%之间;山梨酸的线性范围0～160μg/ml,r=0.999 9,最低检出浓度为0.68 mg/kg,加标回收率在95.9%～100.8%之间。结论该方法样品处理简单、快速,试剂消耗少,线性范围宽,精密度和准确度较高,完全能够满足含油食品中的苯甲酸、山梨酸的检测。     

工作场所空气中甲酸、乙酸离子色谱检测方法的研究

目的建立工作场所空气中有毒物质(甲酸、乙酸)离子色谱检测方法。方法采用硅胶管采集工作场所空气中甲酸、乙酸,碳酸盐淋洗液1.0 mM Na2CO3/0.1 mM NaHCO3解吸,用AS23色谱柱进行分离,电导检测器检测,以保留时间定性,峰面积定量。结果乙酸、甲酸分离良好,检出限分别是0.3、0.03 mg/L;定量限分别为0.91 mg/L和0.12mg/L;回收率分别为96.5%~104%、95.3%~104%;工作曲线的线性范围分别为0.91~100、0.12~200 mg/L。样品中F-、Cl-、NO3-、PO4-、SO4-等常见阴离子对甲酸、乙酸的分离无干扰。结论该方法一次采样,同时检测甲酸、乙酸,具有操作简便、分离效果好、灵敏度高等优点。适用于工作场所空气中甲酸、乙酸的检测。     

气相色谱法测定食品中山梨酸 苯甲酸的不确定度分析

目的:评估气相色谱法对食品中山梨酸、苯甲酸的检测结果的影响。方法:根据测定方法建立数学模型,然后对不确定度的分量逐一进行计算,最终合成不确定度报告。结果:当K=2(95%置信概率)时,山梨酸、苯甲酸的含量分别为406.8±11.39 mg/kg和905.2±79.66 mg/kg。结论:掌握气相色谱法分析山梨酸、苯甲酸不确定度的方法,确保测量结果的准确性。     

离子色谱法检测唑来膦酸中甲烷磺酸

目的:建立唑来膦酸中甲烷磺酸的离子色谱分析方法。方法:采用SH-AC-1阴离子交换柱(25 cm×4.6 mm,7μm)分离,3.6 mM碳酸钠等度淋洗,抑制电导法检测。结果:在该色谱条件下,9 min内完成甲烷磺酸的分析。在0.05 mg/L～5.0 mg/L范围内线性良好(r=0.9999),样品峰面积的RSD(n=7)为2.41%。加标回收率为97.6%～101.2%。结论:方法、简便、快速、基体干扰小,适用于检测唑来膦酸中的甲基磺酸。     

氢化物发生原子荧光光谱法测定亚麻酸、亚油酸中砷

目的：利用氢化物发生原子荧光分析技术测定亚麻酸、亚油酸中砷。方法：试样采用硝酸、高氯酸混合酸消解。结果：方法检出限为4．1ng／g，测定精密度为2，86％和3．59％，回收率在96．5％-103．4％之间。结论：方法快速，准确可靠，满足亚麻酸、亚油酸中砷的测定。     

生活饮用水中二氯乙酸和三氯乙酸的离子色谱电导测定法

目的:建立生活饮用水中二氯乙酸(DCAA)和三氯乙酸(TCAA)的离子色谱检测法。方法:利用Dionex 2100型离子色谱仪,选用IonPac AS19阴离子色谱分析柱,进样体积500μl,10 mmol/L～45 mmol/L氢氧化钾溶液梯度淋洗,流速1.0 ml/min,电导检测器,0.22μm滤膜过滤后直接进样。结果:本法相关性r>0.999,DCAA和TCAA最低检出限分别为0.003 mg/L和0.005 mg/L,RSD%<4.56%,回收率范围85%～104%。结论:本法具有简便快速,灵敏准确及安全实用的特点,适合生活饮用水大批样品的检测。     

淋洗液在线发生离子色谱法同时测定果汁中的乳酸、富马酸和柠檬酸

目的 建立离子色谱法同时测定果汁中乳酸、富马酸和柠檬酸的分析方法。方法 样品经Ion PAC AS19 型分析柱（250 mm×4 mm）分离,流速为1.00 ml/min,以氢氧化钾溶液梯度淋洗,洗脱后经抑制型电导检测器检测。结果 乳酸、富马酸和柠檬酸的线性范围分别为0.5～50.0、0.02～5.0和0.2～25 mg/L,相关系数分别为0.9985,0.9999和0.9992,方法检出限分别为0.04、0.01和0.03 mg/L,加标回收率为89.9%～112.5%,相对标准偏差为3.98%～6.99%（n = 6）。结论 该方法灵敏度高,操作简便快捷,适用于果汁中乳酸、富马酸和柠檬酸的同时测定。     

毛细管柱气相色谱法同时测定月饼中 苯甲酸、山梨酸、丙酸钙及脱氢乙酸

摘要:目的　建立毛细管柱气相色谱法同时测定月饼中中苯甲酸、山梨酸、丙酸钙及脱氢乙酸的分析方法。方法　样品经石油醚去除脂肪,乙醚提取;丙酮溶解定容,经毛细管柱（BP-21）分离后,用气相色谱 -火焰离子化检测器（FID）采用标准曲线法对4 种防腐剂进行定量分析。结果　4 种防腐剂在BP-21 毛细管柱上完全分离,线性方程相关系数 r＞0.999,检出限0. 67 mg/kg～0.79 mg/kg。在5 个加标浓度水平下,回收率为91.2%～96.0%,相对标准偏差（n＝6）为1.6%～2.9%。结论　该方法前处理简单、结果准确,能够快速、准确地检测月饼中苯甲酸、山梨酸、丙酸钙及脱氢乙酸。     

Docosahexaenoic acid and eicosapentaenoic acid affect ovarian prostaglandin levels differently in rats

Prostaglandins (PGs) play a key role in the regulation of ovulation. Typically, ingestion of the long-chain n-3 polyunsaturated fatty acids (PUFAs), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) has been found to decrease, whereas arachidonic acid (ARA) increases PG biosynthesis in most systems. We hypothesized that DHA and EPA would decrease ovarian PGE₂, enhancing ovulation, with combined EPA and DHA having the greatest effect, whereas ARA would increase PGE₂, suppressing ovulation. Our objective was to determine how 0.3-g/100-g diet DHA and EPA alone or combined, or ARA would affect tissue composition, ovulation, and PG synthesis in rats. After 27 days on diet and ovulation induction, ovaries were isolated and analyzed from 22 pups per diet. Eicosapentaenoic acid alone reduced ovarian n-6 PUFA attributable to reduced ARA incorporation. Arachidonic acid ingestion reduced and EPA enhanced ovarian n-3 PUFA to levels above what was seen with DHA or DHA/EPA combinations. Docosahexaenoic acid alone increased total PGE 1.5-fold over control, whereas neither differed from the remaining treatments. Increased total PGE with DHA was attributable to elevated PGE₃ with PGE₂ unchanged by diet, and PGE₃ only increased with DHA ingestion alone. Total PGF differed from control with the highest DHA intake, alone or combined with EPA, or with ARA ingestion (P < .05). Increased PGF with DHA was attributable to increased PGF_3α. Experimental diets did not alter ovulation from control. Results indicate that DHA and EPA consumption at human achievable doses differently alters ovarian phospholipids and PGs associated with ovulation with potential for significant 3-series PG without significantly perturbing ovulation.     

生活饮用水中二氯乙酸三氯乙酸检测方法的改进

目的改进和优化生活饮用水中二氯乙酸三氯乙酸气相色谱检测方法。方法样品在酸性条件下萃取,再经衍生反应,采用恒温方式毛细管色谱柱分离、ECD检测器气相色谱法测定,内标法定量。结果经改进后的方法通过提高衍生温度为60℃,衍生时间缩短为90min,柱温恒温为90cC,二氯乙酸、三氯乙酸出峰时间缩短。二氯乙酸、三氯乙酸在0-1001xg／L具有良好的线性,相关系数〉0．999,相对标准偏差RSD2．9％～8．8％,回收率为86％一95．4％。结论通过改进优化样品萃取、衍生及色谱条件,缩短了检测时间,减少了试剂的用量。大大提高了工作效率、节约了检测成本,有利于大批水样的分析测定。     

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.     

血乳酸和乳酸清除率与重症脓毒症患儿的预后关系

目的:探讨动脉血乳酸及乳酸清除率动态监测在重症脓毒症患儿预后的临床关系。方法:对收治的重症脓毒症患儿42例入院后均按重症脓毒症的诊断指南中的诊疗方案进行治疗,测定每例患儿复苏前及复苏后动脉血乳酸值,并且计算复苏后1、2、6 h的乳酸清除率。根据预后分为存活组20例与死亡组22例,评价早期乳酸和乳酸清除率与预后的关系。结果:存活组复苏前及复苏后1、2、6 h的乳酸值明显低于死亡组,差异有统计学意义(P<0.05)。存活组复苏后1、2、6 h的乳酸清除率明显高于死亡组,差异有统计学意义(P<0.05)。结论 :动态监测动脉血乳酸及乳酸清除率是判断重症脓毒症患儿预后和病情严重程度的一个良好指标,动脉血乳酸越高病情越重,预后越差;血乳酸清除率越低病情越重,预后越差。     

Punicic acid was metabolised and incorporated in the form of conjugated linoleic acid in different rat tissues

The objective of this study was to evaluate the effects of a supplementation of pomegranate seed oil (PSO), being rich in punicic acid, on the biochemical parameters of healthy rats. PSO was given to the animals intragastrically for 40?days at concentrations of 1%, 2% and 4%. There were no changes in their total body weight gain, their serum biochemical markers, or in the oxidative stress in their tissues. However, the TBARS values were reduced in the brains of the animals, noting that no significant amounts of conjugated fatty acids were found in this tissue. Conjugated linoleic acid (CLA) was present in all the other tissues studied. The results obtained have demonstrated that punicic acid from PSO was metabolised and incorporated in the form of CLA in different rat tissues. It did not cause alterations in their lipid metabolism, nor did it participate in the processes of oxidation inhibition.     

Effect of ascorbic acid intake on tissue dehydroascorbic acid in mice

The effect of ascorbic acid intake on tissue levels of ascorbic acid, dehydroascorbic acid and the ratio of dehydroascorbic acid to ascorbic acid in mice was studied. In general, the trend of changes in tissue concentrations was: ascorbic acid > dehydroascorbic acid ratio of dehydroascorbic acid to ascorbic acid. Mice fed a diet with 1% ascorbic acid had significantly higher concentration of dehydroascorbic acid in the kidney, lung and spleen than did control mice fed an ascorbic acid-free diet. Mice fed a diet with 5% ascorbic acid had elevated levels of dehydroascorbic acid in the brain, kidney, liver, lung and spleen. The kidney and lung had the greatest increase in dehydroascorbic acid concentration, suggesting that these two organs may be important sites for catabolism and elimination of ascorbic acid. In comparison with the corresponding control values, the ratio of dehydroascorbic acid to ascorbic acid was higher in the lung, not different in the liver and spleen, and lower in the kidney of mice fed a diet with 1 or 5% added ascorbic acid. These ratios were higher in the brain of mice fed a diet with 5% added ascorbic acid than in mice fed the ascorbic-acid-free diet. No apparent physiological abnormality in these animals was observed. These effects were stereospecific. Exogenous erythorbic acid, D-isoascorbic acid, a stereoisomer of ascorbic acid, increased dehydroascorbic acid equivalents (the sum of dehydroascorbic and dehydroerythorbic acid) in the kidney, lung, and spleen but the ratios of dehydroascorbic acid plus dehydroerythorbic acid to ascorbic acid plus erythorbic acid were essentially unaffected. A large glucose intake (1 or 5% in the diet) did not have an effect on levels of tissue ascorbic acid or dehydroascorbic acid.     

Gamma-hydroxybutyric acid and alcohol-related syndromes

We report on the effectiveness and safety of gamma-hydroxybutyric acid in the therapy of overt alcohol withdrawal syndromes, their prevention, and the prevention of relapses in formerly detoxified alcoholics. We studied 321 patients (236 men, 85 women), divided into two open-study groups for the treatment and prevention of alcohol withdrawal syndromes and one double-blind study group to evaluate the effects of gamma-hydroxybutyric acid versus placebo on alcoholic craving and relapses in detoxified patients. Gamma-hydroxybutyric acid treatment promptly reduced withdrawal symptoms in all patients and prevented alcohol withdrawal syndromes in 55% of cases. The attenuation of craving in detoxified patients was significantly greater in the gamma-hydroxybutyric acid-treated group in comparison with the placebo-treated group. The therapeutic use of gamma-hydroxybutyric acid was not accompanied by serious side effects. Gamma-hydroxybutyric acid diversion was poorly represented: gamma-hydroxybutyric acid-induced abuse was reported in 4 (1.1%) of 345 treated patients, and only 9 cases of gamma-hydroxybutyric acid acute poisoning were reported in the years 1992–1995. Our results suggest that gamma-hydroxybutyric acid, with a favorable risk/benefit ratio, is a clinically useful drug in the treatment of alcohol dependence.     

对苯二甲酸的致畸毒性研究

研究对苯二甲酸的致畸毒性,为制订卫生标准提供依据。方法：选择受孕的ＳＤ大鼠,通过灌胃途径在妊娠等７天给予ＴＰＡ,剂量组分别为：５０００、５０００、５０ｍｇ／ｋｇ,对照给予等量植物油,妊娠第２０天断颈处死动物,检查胎鼠内脏和骨骼有无异常。结果：５０００ｍｇ／ｋｇ剂量组母鼠体重增长量,胎鼠体重,体长均低于对照组,胎鼠内脏检查未见异常,骨骼检查仅见几例波状肋但无统计意义,其它未见异常。结论本次研究结果提