液相色谱-串联质谱法测定毛织物中的氯菊酯防蛀剂

文章建立了一种高效液相色谱-串联质谱法测定毛织物中氯菊酯防虫蛀剂含量的方法。毛织物中的氯菊酯经甲醇浸泡、超声提取、过滤后,利用液相色谱分离氯菊酯异构体,采用质谱-选择离子监测法对其作定量测定。顺、反氯菊酯的标准曲线线性相关系数均大于0.999 2,线性范围为0.01~1μg/m L。该方法对顺式氯菊酯的检出限为0.707 ng/m L、反式氯菊酯为1.645 ng/m L。在2 mg/kg、20 mg/kg的2个添加水平范围内的平均回收率在92.6%~96.9%之间,相对标准偏差(n=7)在0.2%~7.6%之间。与高效液相色谱法相比杂质干扰小,准确性高,检测限更低。     

茶叶中锌含量的测量不确定度评定

通过对火焰原子吸收光谱法测定茶叶中锌含量的整个测定过程进行研究,系统分析该法测量结果的不确定度来源,并对不确定度各个分量进行评估和合成。结果显示,测量用样品不确定度分量是影响锌含量测定不确定度的主要原因,当锌测定结果为15.76mg/kg时,扩展不确定度为2.68mg/kg。该样品锌测定结果为C=(15.76±2.68)mg/kg,k=2,P=95%。     

气相色谱串联质谱法测定大米中联苯菊酯残留量的不确定度评定

对气相色谱串联质谱法测定大米中联苯菊酯残留量的测量不确定度进行评定。建立数学模型,分析不确定度来源,计算不确定度分量,并合成测量结果的不确定度,为实验室大米中联苯菊酯检测过程中的质量控制提供有效、可靠的检测数据。实验结果表明:当样品中联苯菊酯含量为0.044 0 mg/kg时,方法引入的扩展不确定度为0.000 82 mg/kg。通过比较各个分量不确定度,发现测量重复性带来的不确定度影响最大。     

高效液相色谱-质谱联用法测定酱油中三氯蔗糖的不确定度评估

采用高效液相色谱-质谱联用法测定酱油中三氯蔗糖的含量,建立了不确定度评定模型。系统分析并计算测量全过程中的不确定度各分量,通过比较各分量的大小,得出影响三氯蔗糖结果的不确定度来源主要是重复性测定和标准溶液的配制。最终计算得到三氯蔗糖的总合成标准不确定度为0.339 mg/kg,扩展不确定度为0.677 mg/kg,测量结果不确定度表示为[（13.38±0.677） mg/kg,k=2]。     

微波消解-电感耦合等离子体发射光谱法测定牡蛎中锌的不确定度评定

对微波消解-电感耦合等离子体发射光谱法测定牡蛎中锌含量的不确定度来源进行了分析,依据JJF 1059-1999《测量不确定度评定与表示》,量化了各不确定度分量,计算合成不确定度,最终得出测定结果的扩展不确定度。结果表明,测定结果的不确定度主要包括校准曲线拟合、测量重复性、标准溶液配制、样品称量以及样品定容体积,其相对标准不确定度分量分别为0.016、0.004 7、0.001 4、0.002 2和0.000 8。通过对不确定度分量的分析,指出校准曲线拟合是影响测定结果不确定度的主要因素,测量重复性、标准溶液配制以及样品称量和定容过程对最终结果不确定度影响亦不可忽略。测定结果的合成标准不确定度为13.29 mg/kg,扩展不确定度为26.58 mg/kg（k = 2）。因此,牡蛎中锌含量的测定结果为（781.98±26.58）mg/kg（k = 2,P = 95%）。     

高效液相色谱法测定能力验证样品(饮料)中咖啡因含量不确定度评定

目的 对高效液相色谱法测定能力验证样品(饮料)中咖啡因含量的不确定度进行评定。方法 根据JJF1059.1-2012标准要求, 建立不确定度评估的数学模型, 通过对不确定度的各主要分量进行分析计算, 得出合成不确定度以及扩展不确定度, 最终进行测定结果的不确定度评定。结果 当能力验证样品中咖啡因的测定结果为156.9 mg/kg时, 在95%的置信区间下, 其扩展不确定度为5.8 mg/kg (k=2)。结论 采用高效液相色谱法测定饮料中咖啡因含量, 其不确定度的主要来源为标准溶液配制和标准曲线拟合, 该评估模型为检测饮料中咖啡因的不确定度评估提供了参考依据。     

饮料中日落黄含量测定的不确定度评定

目的对高效液相色谱法测定饮料中日落黄含量进行不确定度评定。方法分析日落黄含量测定过程中的样品称量等各种不确定因素,分析实验过程中各种不确定度的来源,计算合成不确定度和扩展不确定度。结果当日落黄含量为32 mg/kg时,其扩展不确定度为2.8 mg/kg(k=2)。由各不确定度分量的计算结果可知,日落黄标准溶液的配制过程对实验结果的不确定度影响最大。结论通过对测定过程的不确定度评定,可以把握不确定度的主要来源,为饮料中日落黄含量的测定提供理论依据,提高测定的精准度。     

超高效液相色谱-串联质谱法测定凉茶中对乙酰氨基酚的不确定度评定

目的 采用超高效液相色谱-串联质谱法(UPLC-MS/MS)测定饮料中对乙酰氨基酚的含量,进行不确定度分析。方法 依据BJS 201713《饮料、茶叶及相关制品中对乙酰氨基酚等59种化合物的测定》,采用超高效液相色谱-串联质谱法(UPLC-MS/MS)测定对乙酰氨基酚的含量,并构建不确定度评定的模型,分析不确度分量的来源,对各分量进行不确定度评定。结果 饮料中对乙酰氨基酚含量为0.406mg/kg,其测量扩展不确定度为U=0.022mg/kg,k=2。结论 该研究可为实验室饮料中对乙酰氨基酚含量的测定结果质量提供参考,其中标准溶液配制、标准曲线拟合、重复性实验是标准不确定度的重要影响分量。     

高效液相色谱法测定粮食中赭曲霉毒素A含量的不确定度评定

对高效液相色谱法测定粮食中赭曲霉毒素A含量的测量不确定度进行评定。建立数学模型,分析不确定度来源,计算不确定度分量,并合成测量结果的不确定度。本次评定结果表明:赭曲霉毒素A测量结果的不确定度主要来自样品不均匀性、浓度、体积、称量、提取效率,重复性6个因素,其中浓度因素引入的不确定度分量贡献最大,其次是体积因素,而由试样称量因素引入的不确定度分量最小。高效液相色谱法测定粮食中赭曲霉毒素A的含量为4.48μg/kg时,其扩展不确定度为0.41μg/kg,k=2。     

超高效液相色谱串联质谱法测定豆芽中恩诺沙星、环丙沙星残留量的不确定度评定

利用超高效液相色谱—串联质谱法测定豆芽中恩诺沙星、环丙沙星的残留量,并根据建立的数学模型评定该方法的不确定度的各分量。样品用0.1%甲酸—乙腈提取,经prime HLB固相小柱净化,超高效液相色谱—串联质谱测定,内标法定量。评定结果表明,标准曲线拟合和标准溶液配置所产生的的不确定度分量最大。当豆芽中恩诺沙星含量为8.6 μg/kg时,其扩展不确定度为1.5 μg/kg(k=2),环丙沙星含量为11.0 μg/kg时,其扩展不确定度为2.3 μg/kg(k=2)。     

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。     

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.     

Moulds and mycotoxins in sorghum stored in traditional containers in India

Various traditional containers have been used in India for storage of sorghum grains. Sorghum is susceptible to fungal infestation and toxin elaboration. The present study relates to the mould and mycotoxin contamination (aflatoxin B₁ and T-2 toxin) in stored sorghum in different storage containers viz. “Kotlu” (Storage rooms), earthenware pots, gunny bags and reed baskets. Aspergillus sp. and Fusarium sp. were the prominent genera and the “Kotlu” form of storage was most susceptible to fungal attack. Storage treatment had little effect on fungal contamination, but despite the fungal infestation, the mycotoxin contamination was found to be very low.     

中国固态发酵白酒中功能细菌研究进展

细菌是白酒酿造3大类微生物之一,其在白酒生产中有着重要的作用,如:芽孢杆菌、乳酸菌、放线菌和梭菌等,它们能产生酯类、有机酸、吡嗪、萜烯等微量成分,从而影响白酒的风味与品质。基于细菌在白酒中的重要功能以及微生物分离培养技术和分析检测技术的进步,近年来相关研究越来越深入。该文综述了近年来白酒功能细菌的研究进展,介绍了酿酒各个环节中主要功能细菌及其在白酒中的作用,旨在为白酒功能细菌的研究提供参考。     

Fungicides in forestry in Great Britain

In Great Britain, fungicides are used in the forest only for the control of root and stem rot, caused by Fames annosus. In forest nurseries they are erriployed on a small scale to control damping-off, grey mould (Botrytis cinerea), needle-cast of pine caused by Lophodermium pinastri, needle-cast of larch caused by Meria laricis, needle blight of Western red cedar (Thuja plicata) caused by Didymascella thujina, and oak mildew (Microsphaera alphitoides).