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1.
功能性化妆品常被非法添加禁限用物质,不仅侵害消费者利益和身体健康,也扰乱了市场秩序。该文按检测的有害物质分类,重点讨论了近些年非法添加的药用物质(激素、抗生素)、防腐剂、防晒剂和其他有毒有害物质的较新颖的前处理技术和检测方法,并对化妆品检测方法的发展前景进行了展望,引用文献86篇。  相似文献   

2.
采用旋风熔融炉对焚烧飞灰进行熔融试验,分析了CaO、SiO2、MgO等添加剂对熔渣熔融特性的影响。结果表明,CaO添加量在5%时可有效地控制飞灰熔点,熔渣中晶体相的比例较少,稳定性较好;添加SiO2有利于降低飞灰的熔点,随着SiO2添加量的增加,熔渣中玻璃态无定形物质增多,熔渣稳定性就越好;MgO对飞灰中硅酸盐或硅铝酸盐的网状结构有破坏作用,可降低熔融体黏度,MgO的添加可使熔渣中的玻璃态物质增多,晶体相转变为无定形熔渣,MgO添加量大于5%时,可促使试样达到较好的熔融效果。  相似文献   

3.
非水胶束电动色谱分离邻苯二甲酸酯类化合物   总被引:2,自引:0,他引:2  
非水胶束电动色谱(NAMEKC)兼具非水毛细管电泳的优点和胶束电动色谱的分离机制,尤其适于对强疏水性化合物进行分离分析。在以甲酰胺为非水溶剂的电泳介质中,采用十二烷基硫酸钠(SDS)形成胶束相,开展NAMEKC方法的研究。通过添加水溶液、调节水溶液酸度、添加有机溶剂、改变SDS浓度等操作条件的考察,在15 min 内实现了3种美国环保局优先监测的污染物——邻苯二甲酸二甲酯、邻苯二甲酸二乙酯、邻苯二甲酸二丁酯的分离。分离度最小者为1.5,检测限优于3.04 mmol/L(以信噪比为3计)。3种典型的强疏水性物质的成功分离,显示出NAMEKC方法在分离疏水性物质方面的优势,扩展了NAMEKC在电中性有机物分析中的应用。  相似文献   

4.
应用亲水作用色谱(HILIC)对从市场上购买的鸡蛋和肉中的三聚氰胺及三聚氰胺降解产物三聚氰酸二酰胺进行了检测。采用的色谱柱为ZIC-HILIC柱,流动相为3 mmol/L磷酸二氢铵溶液(pH 6.9)-乙腈(20:80, v/v),流速为0.8 mL/min,检测波长为220 nm。在该体系下,三聚氰胺和三聚氰酸二酰胺的保留时间适中,与样品中的内源性物质有良好的分离。样品经0.1%磷酸提取,偏磷酸及乙腈沉淀蛋白质和糖类物质,以及P-SCX固相萃取柱净化。三聚氰胺和三聚氰酸二酰胺在0.4~40 mg/L范围内与峰面积呈良好的线性关系,样品定量限(按信噪比(S/N)不小于10计)为2 mg/kg,在2~10 mg/kg添加水平下的平均回收率为80%~105%,相对标准偏差小于10%。该方法具有良好的分离选择性,可用于鸡蛋和肉中三聚氰胺和三聚氰酸二酰胺的同时检测。  相似文献   

5.
提出了一种适用于微量气体定量分析的大小球三步同位素稀释质谱法,并给出其实验模型和不确定度理论分析结果。通过引入三步稀释过程,不涉及稀释剂的纯度、丰度、添加质量等方面的数据,仅需测定各步稀释剂质量之比,在其中的两步反稀释过程中使用了基标准纯物质,从而使微量气体的定量分析结果可溯源至基标准纯物质。该方法解决了已有同位素稀释质谱法在微量气体定量分析中的难题。  相似文献   

6.
双亲分子在溶液中可以缔合形成胶束、囊泡、液晶、乳液等有序分子聚集体。在分子中引入功能性的基团,通过改变分子的结构、浓度或引入外部刺激,可以对有序分子聚集体的类型和性能进行调控。光作为一种绿色可控的清洁能源,是一种理想的外部刺激信号。在双亲分子中引入感光基团,可以通过光照调节有序聚集体的组装,并进一步实现功能性的调控。本文综述了近年来在光调控分子有序聚集体方面的研究及其在生物、传导、纳米材料制备中的应用。同时,对光调控的功能性有序分子聚集体未来的发展前景进行了展望。  相似文献   

7.
《化学分析计量》2011,(3):32-32
为严厉打击食品生产经营中违法添加非食用物质、滥用食品添加剂以及饲料、水产养殖中使用违禁药物,卫生部、农业部等部门根据风险监测和监督检查中发现的问题,不断更新非法使用物质名单,至今已公布151种食品和饲料中非法添加名单,包括47种可能在食品中“违法添加的非食用物质”、22种“易滥用食品添加剂”和82种“禁止在饲料、动物饮用水和畜禽水产养殖过程中使用的药物和物质”的名单。  相似文献   

8.
采用气相色谱-质谱联用法(GC-MS)对3种水性涂料中的半挥发性物质进行非靶向筛查。以甲醇为溶剂超声辅助提取3种自然干燥水性涂料中的化合物后,结合MS-DIAL软件、保留指数和NIST质谱库进行非靶向定性分析,初步得到包括芳香烃、羰基化合物、酯基化合物等63种半挥发性化合物。丙烯酸-2-乙基己酯、丙烯酸异辛酯和甲基丙烯酸-2-乙基己酯是样品涂料中的聚合单体,并在3种样品中识别出不同含量的添加助剂,例如三乙二醇单丁醚、2, 4, 7, 9-四甲基-5-癸炔-4,7-二醇等,以及包括2-乙基己醇、月桂醇、邻苯二甲酸二丁酯等疑似非有意添加物质(NIAS)。利用T.E.S.T(Toxicity Estimation Software Tool)软件和VEGA QSAR软件分别预测评估其急性毒性、发育毒性、致癌致突变性和Cramer等级。结果显示,水性涂料的安全风险主要来源于含有Cl、N和Si元素的NIAS,以及2-乙基己醇、苯乙烯、丙烯酸-2-乙基己酯等物质,因此需重点关注,而其余有意添加物质(IAS)的潜在毒性危害均较低。  相似文献   

9.
为了提高生物质气化制氢效率,综合利用工业固废资源,利用钙基废弃物——电石渣作为CO2吸附剂,在两段式固定床上探究了钙基废弃物的添加量、反应温度对生物质气化制氢特性的影响,着重研究了吸附剂在实际应用中的循环吸附性能,并以此探讨了电石渣对生物质吸附增强气化的影响机制。结果表明,随着电石渣添加量的逐渐增加,H2产量和含量都呈现出增加的趋势。而随着温度的升高,H2产量和含量先增加后减小。当CaO/C物质的量比为1,重整段温度为700℃时,气体产物中的H2产量和含量为154.34 m L/g(生物质)和26.76%,获得最大值。当电石渣循环次数小于5时,H2的含量和产量相较于初次反应都有所增加。  相似文献   

10.
高效液相色谱法直接拆分非甾体解热镇痛药物对映体   总被引:3,自引:0,他引:3  
使用Kromasil CHI-TBB手性固定相,分离了非甾体解热镇痛药卡洛芬,氟吡洛芬,非诺洛芬,酮洛芬,吡咯芬和萘普生等对映体。结果表明,这种以酒石酸二酰胺为手性中心的商业化手性固定相,适合于在正相条件下分离上述药物对映体,对映体分离因子和分析时间可以通过向流动相中添加极性物质如异丙醇,甲基叔丁醚等来进行调节。  相似文献   

11.
叶童  陈雨  符杰  张爱茜  傅建捷 《色谱》2021,39(2):184-196
全氟和多氟化合物(perfluoroalkyl and poly-fluoroalkylated substances, PFASs)在环境中有极强的持久性和生物富集能力,在全球生态系统及人体中已被普遍检出,其潜在的毒性引起了人们高度关注。蛋是卵生动物生命的起源,同时其营养丰富,是人类主要的蛋白质来源之一,因此,蛋中的污染物水平一方面有可能影响卵生动物种族繁衍,另一方面也关系到人类的健康风险。近年来禽蛋类样品作为非损伤性生物基质已广泛应用于生物体和生态系统污染情况的评估,同时利用蛋类样品中污染物水平评估相应的遗传发育毒性风险和摄入健康风险的研究也逐渐增多。该文对现有文献中蛋中PFASs的样品前处理和仪器检测方法进行了归纳总结,并且对蛋作为PFASs污染指示物的适用性和先进性进行了讨论。  相似文献   

12.
In many bird species, egg membranes can be obtained non‐invasively after the chicks have hatched, and stable isotope analysis of egg membranes can be used to study the diet and foraging distribution of these birds during egg formation. It has been suggested that the enrichment factors of albumen and egg membranes differ for 13C, but are similar for 15N. In this study, we compared carbon and nitrogen stable isotopes of the membranes and albumen of individual eggs of three wild seabird species, the Southern Rockhopper penguin Eudyptes chrysocome, the Imperial shag Phalacrocorax atriceps albiventer, and the Thin‐billed prion Pachyptila belcheri. We also included chicken eggs for comparison. Egg membranes were generally enriched in 13C, compared with albumen. The difference varied between species, with 2.1‰ in Rockhopper penguins, 1.6‰ in Imperial shags, but only 0.5‰ in Thin‐billed prions and 0.4‰ in chicken eggs. Egg membranes were slightly enriched in 15N in Imperial shags (0.9‰) and chickens (0.5‰), compared with albumen, while there was no difference for Thin‐billed prions and Rockhopper penguins. The isotopic values of carbon and nitrogen were correlated between albumen and egg membranes of individual eggs, suggesting that egg membranes can be used reliably to investigate trophic differences between individuals, seasons or colonies. Species‐specific mathematical corrections could be used to compare results across studies that use different egg components. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

13.
Both the German and European organic food markets are growing fast, and there is also a rising demand for organic chicken eggs. Consumers are willing to pay higher prices for organic eggs produced in an animal-appropriate environment considering animal welfare. Strict labelling requirements do not prevent chicken eggs from being a subject of food fraud. Conventionally produced (barn/free-range) eggs can easily be mislabeled as organic eggs. Especially because the demand for organically produced chicken eggs is likely to exceed supply in the future, mislabeling appears to be a realistic scenario. Therefore, there is a need for analytical methods that are suitable to classify eggs as being either conventionally or organically produced. Nuclear magnetic resonance (NMR) spectroscopy in combination with multivariate data analysis is a suitable tool to screen eggs according to the different systems of husbandry. Sample preparation is based on a fat extraction method, which was optimised for application to freeze-dried egg yolk. Samples were analysed using typical q-NMR parameters. A nontargeted approach was used for the analysis of the 1H NMR data. Principal component analysis (PCA) was applied followed by a linear discriminant analysis (PCA-LDA) and Monte Carlo cross-validation. In total, 344 chicken eggs (214 barn/free-range eggs and 130 eggs from organic farms), most of them originating from Germany, were used to build and validate the prediction model. The results showed that the prediction model allowed for the correct classification of about 93% of the organic eggs.  相似文献   

14.
Summary National Institute of Standards and Technology (NIST) Standard Reference Material (SRM) 1563-2, Cholesterol and Fat-Soluble Vitamins in Coconut Oil, and SRM 1845, Cholesterol in Whole Egg Powder, were used to monitor the accuracy and precision of analyses in a recent nationwide study of cholesterol in eggs. A two-phase study was conducted between June, 1988 and May, 1989 by USDA in collaboration with the egg industry to update the USDA nutrient data for eggs. Determination of cholesterol levels received special emphasis since dietary cholesterol is monitored as part of the assessment of the relationship between diet and coronary disease. During each phase of the study eggs were collected from 122 of the top 200 US egg handlers in six regions of the country, representing 67% of the nation's monthly egg production. During Phase I egg yolks were composited into 24 analytical samples. As a result of low variance in cholesterol values for Phase I, egg yolks in Phase II were composited into 6 samples. The selection of the analytical contractor was based on results of analyses of SRM 1563-2, a USDA frozen egg material, and a whole egg powder material (SRM 1845, candidate status) submitted by several laboratories. In all cases the results by the selected contractor were within 1% of the certified or recommended values. The contractor used SRM 1563-2 as well as an in-house cholesterol-spiked oil research material to validate the modified AOAC method which incorporated ethanolic potassium hydroxide saponification followed by gas chromatography. During the analysis of nationwide samples the contractor analyzed SRMs 1563-2 and 1845, as well as the cholesterol-spiked oil and the USDA frozen egg material to monitor accuracy and precision. Over the course of the study coefficients of variation for all materials were less than 5%. As a result of rigorous quality control the cholesterol results for eggs have been regarded with confidence and used to update various public and private data bases used to monitor dietary cholesterol levels.  相似文献   

15.
C A Kan  H J Keukens  M J Tomassen 《The Analyst》1998,123(12):2525-2527
Flubendazole residues in eggs were experimentally induced by providing groups of 8 laying hens feed with approximately 3, 10 and 30 mg kg-1 flubendazole for 21 days. Eggs were sampled during this period and one week after the administration. Samples of both whole egg and egg white/yolk were analysed separately. Flubendazole analysis was performed by reversed phase HPLC and UV detection at 250 nm (eggs) or 320 nm (feed). The limit of detection (LOD) for flubendazole in feed was 0.3 mg kg-1 and in whole egg 0.012 mg kg-1. Both the hydrolysed and reduced metabolites of flubendazole were also determined quantitatively. The eggs of control hens housed in the same room during the study period did not contain any detectable flubendazole or metabolite residue. The eggs from the lowest dosed group (3 mg kg-1 feed) did contain residues, but most of them were only slightly higher than the LOD. Residues in eggs collected from the laying hens that obtained feed with 10 and 30 mg kg-1 flubendazole reached a plateau level after some 10 days and there was a good dose response relation between levels in feed and those in eggs. The residues of parent compound and metabolites almost exclusively occurred in yolk, the metabolites accounting for some 60-65% of the total residue. The residues of the parent compound and its metabolites declined below 100 micrograms kg-1 5 days after the administration of dosed feed had ended.  相似文献   

16.

Background  

BIR family proteins are evolutionarily conserved anti-apoptotic molecules. One member of Xenopus BIR family proteins, xEIAP/XLX, is a weak apoptosis inhibitor and rapidly degraded in a cell-free apoptotic execution system derived from interphase egg extracts. However, unfertilized eggs are naturally arrested at the metaphase of meiosis II by the concerted activities of Mos-MEK-p42MAPK-p90Rsk kinase cascade (cytostatic factor pathway) and many mitotic kinases. Previous studies suggest that cytostatic factor-arrested egg extracts are more resistant to spontaneous apoptosis than interphase egg extracts in a p42MAPK-dependent manner. We tested whether xEIAP/XLX might be phosphorylated in cytostatic factor-arrested egg extracts, and also examined whether xEIAP/XLX could be functionally regulated by phosphorylation.  相似文献   

17.
Abstract

Amphibian egg-jelly coat plays an important role in successful fertilization and development. Here, we ask whether proteins like allurin in the jelly coats of frog eggs might influence fertilization rate success. Using in vitro fertilization of Albanian water frog, Pelophylax shqipericus, we found that body cavity eggs or eggs deprived of jelly coat were not fertilized, compromising the success of in vitro fertilization procedure. When de-jellied eggs were inseminated with sperm suspension, the fertilization efficiency is dramatically decreased even inhibited, suggesting that the gel structure is one of the major factors in the achievement of fertilization in the frogs. Fertilization of de-jellied eggs with sperm pre-treated with egg jelly coat, restored the fertilization competency. Such a result suggests that egg jelly coat probably guides the sperm to the egg surface while maintaining the fertilization ability, contributing to a successful in vitro fertilization of Pelophylax shqipericus.  相似文献   

18.
Modifying hen fodder is a common way of changing eggs composition today. However, there is no information on the effect of the source of protein in the fodder replacement on egg allergenicity. This research aimed to detect potential differences in the immunoreactivity and protein composition of eggs from hens fed with fodder containing legume. The aim of the first step of the study was to select the proper solvent for extracting allergenic proteins from hen eggs. Two of them (containing Tween 20 and Triton 100) were selected, based on protein profile and concentration analysis. Egg-white- and egg-yolk-proteins extracts prepared with them were checked for potential differences, using SDS-PAGE electrophoresis, and then the Western-blot method, using sera from children allergic to eggs and soy. Preliminary studies on the influence of fodder composition on the composition of egg proteins suggest that the addition of soy and lupine to fodder modifies the expression of egg proteins. The observed differences in the immunoreactivity of proteins contained in hen egg-white samples do not seem to be as significant as the appearance of protein with a molecular weight of ~13 kDa in the yolk of eggs obtained from soybean-fed hens. This protein may increase the immunoreactivity of eggs for children allergic solely to soy.  相似文献   

19.
This study aimed to compare folate contents in hen eggs from four different farming systems, namely organic, free range, barn, and cage one. Folate retention during egg boiling was studied as well. The contents of individual folate vitamers were determined using the high-performance liquid chromatography method (HPLC), following trienzyme treatment. Folate content in eggs differed significantly (p < 0.05) due to the rearing system, with the highest mean content determined in the eggs from organic farming (113.8 µg/100 g). According to this study, one egg (60 g) may provide 40–86 µg of folates, which corresponds to 10–22% of the recommended daily intake for adults, 400 µg according to the Nutrition Standards for the Polish Population. The predominant folate form found in egg was 5-methyltetrahydrofolate, which showed considerably greater stability under boiling compared to 10-formylfolic acid present in a lower amount. In most eggs tested, the losses in total folate content did not exceed 15%. The color of yolk of the most folate-abundant organic eggs, had the highest value of lightness (L*) and the lowest value of redness (a*). This, however, does not correspond to consumer preferences of intense golden yolk color.  相似文献   

20.
The radiosensitivity of codling moth, Cydia pomonella (L.), eggs in different stages of development was studied. Eggs ranging in age from 1–24 to 97–120 h were exposed, at 24 h intervals, to gamma radiation doses ranging from 10 to 350 Gy. The effects of gamma radiation on egg hatch, pupation and adult emergence was examined. Results showed that the radiosensitivity of codling moth eggs decreased with increasing age. Egg hatch in 1–24 h old eggs was significantly affected at 20 Gy dose and at 60 Gy dose, egg hatch decreased to about 1%. At the age of 25–48 h, however, egg hatch at 60 Gy dose was about 10%, and egg sensitivity to gamma irradiation decreased significantly in the 49–72 h age group; 60 Gy dose had no significant effect on egg hatch. Eggs irradiated few hours before hatch (at the blackhead stage), were the most resistant ones; 100 Gy had no significant effect on egg hatch and at 350 Gy dose over 56% of the eggs hatched. When adult emergence was used as a criterion for measuring effectiveness, however, the effect of gamma radiation was very sever. A dose of 60 Gy completely prevented adult emergence and at 100 Gy dose all resulted larvae died before pupation.  相似文献   

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