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尼泊金酯类的微波合成 总被引:32,自引:1,他引:32
尼泊金酯类防腐剂(即对羟基苯甲酸甲、乙、丙、丁酯)由于毒性极低,无刺激性及适用于较宽pH范围等特点,广泛用于食品、化妆品和医药工业。该类防腐剂无论是采用国际流行的工艺或国内生产工艺,均存在酯化时间长(一般为5h)、产率低等问题。虽经改进,但也需3h以上,且添加去水剂-苯后,不仅使工艺难 相似文献
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搅拌棒吸附萃取结合气相色谱/质谱/质谱法同时测定饮料和果酱中的7种防腐剂 总被引:3,自引:0,他引:3
建立了搅拌棒吸附萃取进行前处理,气相色谱-质谱/质谱法测定饮料和果酱中7种食品防腐剂的方法.饮料和果酱样品用pH=3的30% NaCl溶液稀释,使用搅拌棒进行吸附萃取,吸附在搅拌棒上的防腐剂在热解析单元进行热解析,在冷进样口进行捕集后通过程序升温进入气相色谱,使用串联质谱的多反应监测(MRM)同时检测饮料和果酱中的7种防腐剂(苯甲酸、山梨酸以及对羟基苯甲酸甲酯、对羟基苯甲酸丙酯、对羟基苯甲酸异丙酯、对羟基苯甲酸异丁酯和对羟基苯甲酸庚酯).苯甲酸、山梨酸在40~400 mg/L浓度范围内,对羟基苯甲酸甲酯、对羟基苯甲酸丙酯、对羟基苯甲酸异丙酯和对羟基苯甲酸异丁酯在4~40 mg/L浓度范围内,对羟基苯甲酸正庚酯在0.4~4 mg/L浓度范围内,各组分响应峰面积与其相应浓度呈良好相关性,r>0.99.苯甲酸和山梨酸的检出限分别为37和47 mg/L,对羟基苯甲酸酯类为0.62~6.67 mg/L.方法的回收率为84.0%~125.0%;精确度为3.0%~18.1%.本方法灵敏度高,能够同时快速检测饮料和果酱中7种防腐剂. 相似文献
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研制了一套全自动高精度可控温定量毛细管电泳仪,通过引入10 n L的进样阀实现定量进样,配合自主研制的自动进样系统和恒温液冷系统,以提高毛细管电泳的定量重复性和准确性。采用全自动定量胶束电动毛细管色谱(q MEKC)测定市售化妆品中苯甲酸、对羟基苯甲酸甲酯(MP)、对羟基苯甲酸乙酯(EP)、对羟基苯甲酸丙酯(PP)、对羟基苯甲酸丁酯(BP)5种防腐剂的含量,优化了分析条件。以15 mmol/L硼砂-100 mmol/L SDS混合溶液(p H 9.3)为背景电解质溶液,工作电压为20 k V,5种防腐剂在该条件下得到了良好的分离和定量结果,峰面积的相对标准偏差(RSD)小于2%。该方法快速、准确,对于化妆品中防腐剂的限用量控制具有重要意义。 相似文献
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快速气相色谱法测定食品中的常见防腐剂 总被引:13,自引:0,他引:13
摘要:建立了一种分离测定食品中6种常见防腐剂(山梨酸,苯甲酸,对羟基苯甲酸甲酯、对羟基苯甲酸乙酯、对羟基苯甲酸丙酯、对羟基苯甲酸丁酯)的简单、准确的快速气相色谱方法,采用长10m,内径100μm的HP-5熔融石英毛细管柱,在快速程序升温条件下,6种常见防腐剂的分析时间为1.3min。各组分平均回收率(n=3)为96.45%;检出限为1.2~10μg/mL;线性相关系数大于0.994。该方法已用于实际食品中防腐剂的检测。 相似文献
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凝胶色谱净化-气相色谱法测定酱油中7种防腐剂 总被引:2,自引:0,他引:2
建立了凝胶色谱净化-气相色谱法测定酱油中山梨酸、苯甲酸、脱氢乙酸、对羟基苯甲酸甲酯、对羟基苯甲酸乙酯、对羟基苯甲酸丙酯、对羟基苯甲酸丁酯共7种防腐剂的方法.样品经过乙醚提取,凝胶渗透色谱净化,毛细管柱(Rxi-17,30 m×0.25 mm×0.25μm)分离后,FID检测器检测.7种化合物在10.0~400.0 mg... 相似文献
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上海市胎儿铅暴露状况及其影响因素 总被引:2,自引:0,他引:2
为了解上海市人群的胎儿铅暴露水平及其影响因素,在上海市杨浦区收集脐血标本605份,其中348份标本在严格质量控制下石墨炉子原子吸收光谱法进行血铅测定。并以面谈问卷的形式对脐血铅水平在第70百分位以上和第30百分位以下者进行家庭社会环境和健康状况调查,用多因素统计分析的方法分析对脐血铅水平有明显作用的影响因素,结果发现348例的血铅水平呈正态分布,被测人群中脐血铅范围0.08~0.84μmol/L, 相似文献
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Rosemary Castorina Marie Tysman Asa Bradman Sara Hoover Shoba Iyer Marion Russell 《International journal of environmental analytical chemistry》2016,96(13):1247-1263
There is little published research examining volatile organic compound (VOC) emissions from art markers. In this study, we characterised VOC emission rates from markers commonly used by children at home and in school, and by teachers in their classrooms. We developed a method to measure standardised emission rates under controlled laboratory conditions, focusing on four major marker types: permanent, dry erase, highlighter, and washable. Emission rates for other less common marker types were also measured. We conducted additional experiments determining changes in emission profiles over short and long time periods (several hours up to daily use over about 2 months), as well as during periods of active drawing. We tested a total of 101 markers and report emission rates for 60 chemicals. Permanent and dry erase markers had average total VOC emissions more than 400 times higher than highlighters and washable markers. Alcohols were the most highly emitted class of VOCs from permanent and dry erase markers. Some chemicals associated with potentially serious health concerns were also identified. Future studies that employ full-scale chamber experiments and personal monitoring in classrooms to measure children’s actual exposures are recommended. 相似文献
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刘松影 《广东微量元素科学》1998,5(5):48-51
对35名铅作业工城套的行为功能测验,接触组与对照组比较,16项行为功能测验中有14项得分有统计学意义(P〈0.01或P〈0.05),半数项目行为功能测验得分有随着铅作业工人龄增长而呈该增或该减的趋势。作者认为铅对作业工人行为功能的影响是肯定的,用行为功能测验的方法来研究铅的神经毒性是可取的简便方法。 相似文献
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不同区域儿童血铅浓度及铅危害的防治 总被引:3,自引:0,他引:3
实验选择了生活在杭州市区5 ̄6岁学龄前儿童120名,男女各半,并选择了生活在杭州近郊海查市农村同龄儿童100名为观察对照组,进行了血铅含量的测试。结果显示,生活在杭州市中心的儿童受到铅污染的危害程度比生活在农村的儿童较为严重。以目前公认推荐血铅可接受上限值0.483μmol/L计算,杭州市有49.1%、而海宁农村有31.9%的儿童血铅浓度超过允许标准。儿童的严重铅危害,应引起人们高度重视。 相似文献
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Hyun Ook Seo Myung‐Geun Jeong Kwang‐Dae Kim Dae Han Kim Young Dok Kim Dong Chan Lim 《Surface and interface analysis : SIA》2014,46(8):544-549
Degradation behaviors of poly(3‐hexylthiophene‐2,5‐diyl) (P3HT) layers on NiO in the presence of H2O at ambient pressure and dark conditions were studied using X‐ray photoelectron spectroscopy (XPS). Upon H2O exposure at 120 °C, partial oxidation of P3HT together with molecular water incorporation, but with the maintained local ring‐structure, were deduced by XPS. Valence band spectra of XPS evidenced that the partial oxidation of P3HT local structure could alter π‐conjugation systems of P3HT layers, forming additional electronic states close to its original highest occupied molecular orbital. For comparison, P3HT surface was also exposed to O2, and no change in the S 2p and C 1s spectra was found by O2 exposure at 120 °C, implying that H2O plays a major role at the initial stage of P3HT oxidation. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
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Due to the widespread uses of Ni and Ni alloys, patients undergoing medical treatments can experience inadvertent exposure to the metal, present as a contaminant in fluids for intravenous administration or released from surgical implants and other medical devices. Because of the risk of acute allergic reactions in Ni-sensitive subjects, sources of metal exposure within medical care and its concentrations in biological fluids of potentially exposed patients should be periodically monitored, using reliable analytical procedures, which include strict measures of contamination control. The results of a recent survey on the concentrations of Ni and other potentially toxic metals in human albumin solutions are reported. 相似文献
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铅接触者铅与锰、铬、镍、镉、铜、铁、锌、钙、镁相关关系的分析 总被引:3,自引:0,他引:3
麦剑平 《广东微量元素科学》2001,8(11):23-25
检测了50名名接触者在驱铅前后全血中铅、锰、铬、镍、镉水平以及血清中铜、铁、锌、钙、镁水平,并将其与50名对照组比较。结果表明,铅对人体内钙、镁、锌、铜、铬、镍均有影响。 相似文献
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铅暴露者体内卟啉代谢与膳食调整的探讨 总被引:3,自引:1,他引:3
武汉某蓄电池厂69名长年接触铅作业工人血铅及相应血尿生化指标测定结果表明:平均血铅含量1.48±0.67μmol/L,血红蛋白为129.0±25.4g/L,贫血率为36.3%;血锌原卟啉为6.65±3.65μg/(g.Hb),血δ-氨基酮戊酸脱水酶为59.2±49.5IU/L,尿δ-氨基酮戊酸为5.69±4.44mg/L。同时发现,作业工人膳食总热能、Ca、VitaminA、VitaminB2摄人不足,血铅水平与膳食中磷、VitaminB1、VitaminB2摄人量呈负相关。结合膳食营养素对铅代谢的影响,本文提出了相应的合理膳食建议。 相似文献