生物素测定方法的分析

生物素是一种B族维生素。近几年,生物素受到了广泛的关注,与此同时,生物素测定方法的研究也取得了迅速的发展。文中介绍了近年来生物素测定常用的几种方法,包括微生物法、高压液相色谱法、生物传感器法、毛细管电泳法、荧光法、ELISA法、微分脉冲伏安法,并简单介绍了生物素分析的研究现状与进展。     

生物素测定方法的分析

生物素是一种B族维生素。近几年，生物素受到的广泛的关注，与此同时，生物素测定方法的研究也取得了迅速的发展。本文介绍了近年来生物素测定常用的几种方法，例如微生物法、高压液相色谱法、生物传感器法、毛细管电泳法、荧光法、ELISA法、微分脉冲伏安法，并简单介绍了生物素分析的研究现状与进展。     

油脂中合成抗氧化剂检测技术的研究进展

简要介绍了食用油脂中常用抗氧化剂的种类及其安全性问题.重点阐述了食用油脂中合成抗氧化剂的分析检测方法,包括薄层色谱法、比色法、气相色谱法、高效液相色谱法以及电化学分析法等,分析了这些检测方法的优缺点及使用范围.气相色谱法和高效液相色谱法检出限低,灵敏度和精确度较高,在油脂合成抗氧化剂检测中应用较广;电化学分析法充分利用抗氧化剂的电化学活性进行分析,检测程序简单,灵敏度较高,应用潜力巨大.     

地沟油检测方法的研究进展

地沟油是质量极差的非食用油,若用于食用会严重危害人的身体健康。介绍地沟油的分类、危害以及对地沟油的检测。尤其着重介绍了仪器分析在地沟油检测中的应用,包括电化学分析法、气质联用分析法、高效液相色谱法、离子色谱法、薄层色谱法、原子吸收法、紫外分光光度法、荧光法、红外光谱法、免疫分析法等。     

钛胶RP-HPLC法同时测定5 种维生素

采用钛胶反相色谱柱,建立高效液相色谱法同时测定5 种维生素：烟酸、生物素、烟酰胺、叶酸和钴胺素含量的检测方法。研究5 种维生素的保留行为与磷酸缓冲盐pH值、缓冲盐类型及浓度、柱温和流速的关系,得出了最优色谱条件：于波长210 nm处检测生物素和钴胺素,于波长270 nm处检测烟酸、烟酰胺和叶酸,磷酸盐pH 7.0,浓度5.0 mmol/L,柱温50 ℃,流速0.8 mL/min。分析5 种维生素保留的热力学参数焓、熵和吉布斯自由能。烟酸、生物素、烟酰胺、叶酸和钴胺素标准曲线线性良好（R2＞0.999 0）;烟酸、生物素、烟酰胺、叶酸和钴胺素的检出限分别为6、10、20、22、8 ng/mL;5 种物质的相对标准偏差均低于1.36%;加标回收率范围为92.30%～107.20%。方法的精密度和准确度均可满足高效液相色谱法的测定要求。     

一种生物素产生菌的简便快速平板筛选方法

介绍一种简便快速筛选生物素产生菌的方法,该方法运用微生物生长圈法原理,以生物素营养缺陷型菌株为指示菌。制作混有该指示菌的缺乏生物素的培养基单层平板,将土壤样品稀释涂布在此平板上培养,所形成的菌落如果分泌生物素到培养基中,菌落周围就会产生指示菌的生长圈,由此可初步获得生物素产生菌。实验利用初筛和复筛并结合管碟法检测,从大量土壤样品中筛选产生物素能力较强的菌株,运用高效液相色谱法验证,确定该筛选方法有效可靠。     

动物性食品中喹诺酮类药物残留检测方法的研究进展

对微生物检测法、色谱法、免疫分析法和电化学分析法等目前主要喹诺酮类药物残留的分析方法作了综述,指出色谱法、色/质谱联用法是国际上公认的确认食品中喹诺酮类药物残留的方法,生物传感技术和肢体金免疫法将是今后研究和开发喹诺酮类残留物检测方法的重要方向.     

大豆异黄酮检测方法研究概述

大豆异黄酮检测方法主要有紫外分光光度法、三波长法、高效液相色谱法、高效液相色谱-质谱法、气相色谱法、气相色谱一质谱法、毛细管电泳法、四标样快速测定法、薄层扫描色谱法、双向纸层析色谱法,及医学上荧光免疫法中时间分辨荧光免疫分析法和酶联免疫吸附法等.该文对上述检测方法进行系统总结和分析比较,以期为大豆异黄酮进一步研发提供技...     

α-亚麻酸甾醇酯检测技术研究

植物甾醇酯是一种新型功能性食品添加剂,具有良好亲脂性和降胆固醇效果。采用薄层色谱法、紫外分析法、红外分析法和气相色谱法相结合的方法对α-亚麻酸甾醇酯产品进行分析检测,为α-亚麻酸甾醇酯和甾醇的分离、定性和定量提供参考。     

高效液相色谱法测定保健食品中的生物素

为了测定保健食品中的生物素的含量,建立方便可靠的测定方法,采用高效液相色谱法对保健食品中生物素含量进行了测定。使用HypersilODS色谱柱(4.6mm×250mm,5μm),以乙腈+0.05mol L磷酸二氢钾(15+85,pH=3.5)为流动相,检测波长200nm。方法的加标回收率为86.8%～106.0%,RSD为8.4%,最低检出量为0.5mg kg。该方法简便、准确,有良好的重现性,技术参数指标符合食品理化分析的要求。     

Changes in smoking prevalence in Ukraine in 2001-5

Objectives

To analyse trends in smoking prevalence in Ukraine from three surveys conducted in 2001–5, and to explore correlates of observed changes, in order to estimate the stage of tobacco epidemic in Ukraine.

Design

Repeated national interview surveys in Ukraine in 2001, 2002 and 2005.

Main outcome measure

Prevalence of current smoking among the population aged ⩾15 years.

Results

The age‐standardised prevalence of current smoking in Ukrainian men was 54.8% in 2001 and 66.8% in 2005. Among Ukrainian women, prevalence increased from 11.5% in 2001 to 20.0% in 2005. ORs for yearly increase in prevalence were estimated as 1.164 (95% CI 1.111 to 1.220) for men and 1.187 (1.124 to 1.253) for women, which implies that, on average, 3–4% of men and 1.5–2% of women living in Ukraine join the smoking population each year.

Conclusions

In Ukraine, smoking prevalence is increasing in most population groups. Among men, the medium deprivation group with secondary education has the highest smoking prevalence. Among women, while the most educated, young and those living in larger cities are the leading group for tobacco use, other groups are also increasing their tobacco use. Tobacco promotion efforts appear to have been significantly more effective in Ukraine than smoking control efforts. The decrease in real cigarette prices in Ukraine in 2001–5 could be the main factor explaining the recent growth in smoking prevalence.Ukraine is a large eastern European country with high smoking prevalence. Tobacco products are widely available at very low prices, and the transnational tobacco industry is extremely successful in promoting its products and lobbying for its interests in the legislative field. Advocacy of tobacco control has only recently achieved some success in the legislative field, with the first tobacco control law being adopted in late 2005. Ukraine ratified the Framework Convention on Tobacco Control in 2006, but there is still much cause for concern regarding the enforcement and effectiveness of the adopted legislative measures. Unfortunately, the government is not yet involved in nationwide surveillance of the tobacco problem, and the available data have mostly been gathered with funding from foreign donors. Several attempts have been made to measure the extent of the tobacco epidemic in the countries of the former Soviet Union (FSU).^{1,2,3,4,5,6,7} Most of these studies have shown rather high smoking prevalence among men (50–70%) and comparatively low prevalence among women (5–20%). Most countries in the FSU have similar smoking rates, while certain trends are shown to be related to the differences in how the transnational tobacco industry succeeds in every national tobacco market.⁶ Unfortunately, few studies have been published showing trends in smoking prevalence in the FSU.⁷ In Ukraine, two studies^3,4 provided point estimates of smoking prevalence.The aim of this study was to analyse trends in smoking prevalence in Ukraine, on the basis of three surveys conducted in 2001–5, and to explore correlates of observed changes in order to estimate the stage of the tobacco epidemic in Ukraine.     

2010年河南省部分食品中重金属污染状况分析

了解河南省部分食品中重金属污染的现状。方法 在河南省18个省辖市采集8大类3 657份食品样品,按照国家标准检测食品中铅、镉和汞的含量,检测结果按照GB 2762—2012《食品安全国家标准食品中污染物限量》进行评价。结果 河南省部分食品中铅含量的平均值为0.34 mg/kg,总体超标率为8.8%(320/3 656),其中粮食、肉类和蔬菜中超标率较高,分别为17.2%(95/552)、14.5%(85/587)和10.7%(57/534);部分食品中镉含量的平均值为0.054 mg/kg,总体超标率为3.9%(143/3 657),其中食用菌和蛋类中超标率较高,分别为9.6%(49/508)和8.1%(42/518);部分食品中汞含量的平均值为0.077 mg/kg,总体超标率为8.3%(303/3 657),其中蔬菜和粮食中超标率较高,分别为25.3%(135/534)和12.3%(68/551)。结论 河南省部分食品中铅、汞污染情况较为严重,其中粮食、蔬菜和肉类食品中污染情况尤为突出,需要加强监管。     

2010年山西省食品中食源性致病菌监测分析

目的 了解山西省食源性致病菌的污染现状.方法 按照2010年度《全国食源性致病菌监测工作手册》进行.结果 1 576份样品中共检出阳性菌株149株,检出率为9.45％,其中单核细胞增生李斯特氏菌、副溶血性弧菌污染比较严重,总检出率为9.50％和8.22％,金黄色葡萄球菌、阪崎肠杆菌和沙门氏菌的总检出率分别为3.02％、1.11％和0.87％.不同类别食品中致病菌的检出率差异较大,生肉中致病菌的检出率高居榜首为49.33％,主要污染菌为沙门氏菌、单核细胞增生李斯特氏菌;沙拉中致病菌的检出率为17.39％,主要污染菌为单核细胞增生李斯特氏菌、金黄色葡萄球菌;生食水产品中致病菌的检出率为16.94％,主要污染菌为单核细胞增生李斯特氏菌、副溶血性孤菌;熟肉制品中致病菌的检出率为9.84％,主要污染菌为单核细胞增生李斯特氏菌、金黄色葡萄球菌、沙门氏菌;中式凉拌菜中致病菌的检出率为8.89％,主要污染菌为金黄色葡萄球菌;鲜榨果汁中致病菌的检出率为6.67％,主要污染菌为金黄色葡萄球菌;鲜冻水产品中致病菌的检出率为5.00％,主要污染菌为副溶血性弧菌;婴幼儿配方粉/米粉/谷粉/豆奶粉中阪崎杆菌的检出率为1.11％.结论 山西省多种食品均存在食源性致病菌不同程度的污染,应加大对散装食品、即食食品和生食水产品的监管.     

Heavy metals in vegetables sold in the local market in Jordan

Heavy metals (As, Cd, Co, Cr, Cu, Mn, Ni, Pb and Zn) in various vegetables (cabbage, green onion, lettuce, parsley, rocket, spinach, carrot, onion, potato and cauliflower) from the market in Jordan were measured using inductively coupled plasma-mass spectrometry. As, Cd, Co, Cr, Cu, Mn, Ni, Pb and Zn ranged from 0.009–0.275 mg kg^?1 wet weight, 0.004–0.060 mg kg^?1, 0.003–0.401 mg kg^?1, 0.105–3.51 mg kg^?1, 0.15–1.15 mg kg^?1, 0.93–14.39 mg kg^?1, 0.044–0.702 mg kg^?1, 0.072–0.289 mg kg^?1 and 2.23–6.65 mg kg^?1, respectively. Parsley, followed by spinach, contained the highest concentration of heavy metals. Onion contained high levels of toxic heavy metals. The content of Cu in parsley and spinach and Pb in onion exceeded the Codex limits. However, the daily intake of heavy metals from the tested vegetables was lower than the maximum limits for allowable intake.     

降低劳力输出的同时提高整经生产率

在劳动成本很高的国家,纺织厂遇到了难以找到合适的工人和辅助人员以从事繁重的筒子搬运工作的问题,而且这种问题日益严重。因为按照不同的纱线支数和筒管尺寸,成吨的纱线筒管必须由人工尽快地搬运到位。