蜜饯类食品中苯甲酸 山梨酸和糖精钠的测定

目的:选择一种前处理简单、方便,灵敏度高、重现性好的蜜饯类食品中防腐剂的检测方法。方法:采用反相色谱法测定蜜饯类食品中防腐剂含量;Agilent Eclipse XDB-C18柱(5μm 4.6mm×250mm)液相色谱柱分离,乙酸铵缓冲溶液(0.02 mol/ml)—甲醇(体积比95∶5)作为流动相,二级管阵列为检测器进行检测。结果:山梨酸回收率为97.8%~103.7%,检出限为0.0008 g/kg;苯甲酸回收率为96.2%~99.1%,检出限为0.0008 g/kg;糖精钠回收率为96.5%~98.1%,检出限为0.0013 g/kg。结论:方法具有简便、快速、准确的优点,可用于蜜饯类食品中苯甲酸、山梨酸和糖精钠的检测。     

高效液相色谱-串联质谱法测定饮料中6种食品添加剂

目的建立高效液相色谱-串联质谱法测定饮料中咖啡因、苯甲酸、山梨酸、安赛蜜、糖精钠和甜蜜素含量的分析方法。方法样品经过全自动固相萃取仪ASPEC萃取(萃取小柱为Pro Elut C_(18)500 mg/6 mL),浓缩仪挥干后用流动相溶解定容。样品液采用Agilent SB-C_(18)色谱柱(2.1 mm×50 mm,1.8μm)分离,0.02 mmol/L乙酸铵-甲醇溶液作为流动相,电喷雾正负离子模式下多反应监测(MRM)模式检测。结果样品平均回收率为72.6%~100.5%,精密度为0.3%~3.1%(n=6)。咖啡因、苯甲酸、山梨酸、安赛蜜和甜蜜素在2~200μg/L,糖精钠在8~800μg/L的浓度范围内,线性关系好,r>0.9990,咖啡因、苯甲酸、山梨酸、安赛蜜和甜蜜素的检出限为0.001 mg/kg,糖精钠的检出限为0.004 mg/kg。结论该方法灵敏、准确、快速,适用于饮料中咖啡因、苯甲酸、山梨酸、安赛蜜、糖精钠和甜蜜素的检测。     

云南省2004年部分食品中甜味剂、防腐剂检测分析

目的 通过对2004年云南省市场部分食品的抽查及检测分析,对样品中乙酰磺胺酸钾（安赛蜜）、糖精钠、苯甲酸、山梨酸的添加情况进行分类分析,做一全面了解.方法 采用高效液相色谱法对其进行定量分析.结果 检查样品271件,合格198件,占73.06%.安赛蜜、苯甲酸、山梨酸、糖精钠线性范围均为0.01～0.25 μg,在此范围内线性良好.加标回收率安赛蜜为99.42%～101.01%,苯甲酸为99.98%～100.30%,山梨酸为99.80%～101.06%,糖精钠为100.10%～102.10%.最低检出限：安赛蜜为0.001 μg,苯甲酸为0.001μg,山梨酸为0.001 μg,糖精钠为0.002 μg.结论 检测结果准确、可靠,各次测定结果有很强的可比性,对结果进行分类分析,了解薄弱环节,为卫生监督工作提供实验依据.     

膨化食品中的山梨酸、苯甲酸、糖精钠的超高效液相色谱测定法

目的 建立一种用超高液相色谱法测定膨化食品中山梨酸、苯甲酸、糖精钠的方法.方法 参考国标中高效液相色谱法,改用超高液相色谱并确定测定条件.结果 采用该法得出的校准曲线的相关系数分别为山梨酸:r =0.999 6;苯甲酸:r =0.999 9;糖精钠:r=0.999 9.检出限均为0.001 mg/kg.3种物质的回收率范围为97.2％ ～99.1％.结论 采用超高液相色谱法测定膨化食品中山梨酸、苯甲酸、糖精钠,该法具有灵敏、准确、回收率和重现性好的特点,使得测定山梨酸、苯甲酸、糖精钠的方法更加简便快速、准确可靠.     

UPLC法同时测定食品中5种添加剂

[目的]建立超高效液相色谱UPLC快速分离和测定食品中安赛蜜、苯甲酸、山梨酸、糖精钠、脱氢乙酸等的方法.[方法]样品经沉淀蛋白、超声提取、离心、过滤等预处理,采用乙酸铵(0.02 mol/ml)-甲醇(体积比93:7),检测波长230 nm,二极管阵列检测器,外标法定量.[结论]该方法精密度高、准确性好,样品处理简单,测得安赛蜜、苯甲酸、山梨酸、糖精钠、脱氢乙酸在0.2～20 mg/kg范围内线性良好,回收率在90.1～105.3之间,检出浓度为安赛蜜、苯甲酸、山梨酸0.02 mg/kg,糖精钠、脱氢乙酸0.04 mg/kg.[结论]该方法具有简便、快速、准确的优点,可用于食品中安赛蜜、脱氢乙酸、苯甲酸、山梨酸、糖精钠的检测.     

OSAKA-SODA-CAPCELL-PAK-C18色谱柱同时检测面制品中5种添加剂

目的建立一种快速、简单的可同时测定面制品中安赛蜜、糖精钠、苯甲酸、山梨酸和脱氢乙酸添加剂的高效液相色谱法。方法样品通过氢氧化钠和硫酸锌沉淀后,利用OSAKA-SODA-CAPCELL-PAK-C₁₈(4.6 mm×150 mm,5μm)色谱柱,以乙腈和0.02 mol/L磷酸二氢钾为流动相,梯度洗脱,用二极管阵列检测器检测。安赛蜜、苯甲酸、山梨酸和脱氢乙酸的检测波长为225 nm,糖精钠为205 nm,以保留时间定性,外标法定量分析。结果5种添加剂在0.5μg/ml～50.0μg/ml具有良好的线性关系(r>0.999 9),检出限为0.000 2 g/kg～0.000 6 g/kg,样品的平均回收率为93.6%～105.0%,相对标准偏差为0.16%～1.56%。结论本实验利用CAPCELL-PAK-C₁₈柱,以氢氧化钠和硫酸锌为蛋白沉淀剂,乙腈和磷酸二氢钾为流动相,进一步优化了同时检测面制品中5种添加剂的方法。该方法前处理方便、保留时间稳定、色谱峰型好、分析速度快、回收率高,适用于大批量样品的快速检验。     

果汁中5种添加剂固相萃取离子色谱测定法

目的 建立固相萃取离子色谱法同时测定果汁中山梨酸、甜蜜素、苯甲酸、安赛蜜和糖精钠含量的快速、简便分析方法.方法 100％纯果汁样品经水稀释并调整pH值至9～10之间后,直接过尼龙滤膜和Cleanert-IC C18前处理柱去除杂质和有机物,通过IonPac AS 17-C阴离子交换分析柱,2阶等浓度淋洗液洗脱方式,经离子色谱电导检测后,测定5种添加剂含量.结果 5种添加剂线性范围为0.5～ 10 μg/ml,相关系数在0.999 0 ～0.999 9之间,样品加标回收率在92.8％～107.7％之间,方法检出限为6 mg/kg,精密度为1.3％.结论 该方法简便、快速、准确、可靠,适用于测定果汁饮料中山梨酸、甜蜜素、苯甲酸、安赛蜜和糖精钠的含量,尤其适合大批量样品的测定.     

超高效液相色谱法测定冷面汤中山梨酸、苯甲酸、安赛蜜、糖精钠含量

目的建立超高效液相色谱分析冷面汤中山梨酸、苯甲酸、安赛蜜、糖精钠含量的方法。方法取2 g左右样品,加少量水稀释,用氨水(1+1)溶液调节酸度至pH 6.5～7.5,用水定容至25 ml。所得溶液过0.22μm滤膜,进行超高效液相色谱分离;以C_(18)反相色谱柱为固定相,以乙酸铵溶液+甲醇为流动相进行梯度分析。结果山梨酸、苯甲酸、安赛蜜、糖精钠的质量浓度在0.1～50 mg/L内与峰面积呈线性关系,检出限(3S//N)分别为0.5、0.5、0.5、1.0 mg/Kg。按标准加入法在3个浓度水平上进行回收试验,回收率为86%～96%,测定值的相对标准偏差(n=6)均10%。结论该方法操作简单、干扰小,准确度可靠,能够分析冷面汤中山梨酸、苯甲酸、安赛蜜和糖精钠含量。     

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。     

反相高效液相色谱法同时测定9种食品中乙酰磺胺酸钾、苯甲酸、山梨酸、糖精钠方法的研究

目的：建立一种准确、适用的反相高效液相色谱法同时分离测定9种不同类型食品中常用甜味剂乙酰磺胺酸钾、糖精钠和防腐剂苯甲酸、山梨酸的分析方法。方法：不同类型样品应用不同的前处理方法,用Inertsil ODS-C18反相柱分离,HPLC-486UV测定,外标法定量。结果：乙酸磺胺酸钾、苯甲酸、山梨酸、糖精钠在各种样品中的回收率平均值分别为89.6%,92.4%,90.2%,88.8%,其精密度分别为4.56%,0.0015%,1.32%,2.86%,最小检出限在取样量为10.0 g时,分别为0.00012,0.0002,0.0001,0.0004 mg/g。结论：本方法能满足9种食品中乙酰磺胺酸钾、苯甲酸、山梨酸、糖精钠的同时分析测定要求。     

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.