共查询到19条相似文献,搜索用时 265 毫秒
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本文研究了软泥类玩具材料中硼酸和硼酸盐含量的检测方法,用0.07 mol/L盐酸溶液提取试样,电感耦合等离子体质谱KED模式分析同位素11B,通过硼元素的含量换算成硼酸和硼酸盐来确定软泥类玩具材料中硼酸和硼酸盐的含量。硼元素浓度在2~1000μg/L与其响应值呈线性关系(R^2=0.99984),硼元素、硼酸、硼酸盐的检出限分别为0.042 mg/kg、0.240mg/kg和0.369 mg/kg,定量限分别为0.100 mg/kg、0.572 mg/kg和0.883 mg/kg,加标回收率为87.5%~105.3%,相对标准偏差(RSD,n=7)小于5%。该方法准确度高、精密度好,满足软泥类玩具材料中硼酸和硼酸盐的测定。 相似文献
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《现代商贸工业》2019,(34)
建立一种快速、准确测定紫菜中多种元素的方法。方法采用微波消解对紫菜进行样品前处理,电感耦合等离子体质谱法(ICP-MS)同时测定紫菜中的Ca、Mg、Fe、Mn、Cu、Zn、Cr、Cd、Pb、Hg共10种元素含量。各元素在其标准曲线范围内的相关系数r≥0.999,相对标准偏差RSD≤6.5%,加标回收率在90.0%~101.3%之间。应用所建立的方法对国家标准物质紫菜(GBW10023)和螺旋藻(GBW10025)进行元素分析,各元素测定值均在证书认定值范围内。该方法检验周期短、操作简单、灵敏度高、精密度和准确度高、回收率好,适用于紫菜中多种元素含量的测定分析。 相似文献
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采用ICP-MS与石墨炉原子吸收光谱仪分别测定大米样品中的镉元素,通过微波消解进行前处理,同时进行加标实验和标准物质测定。结果表明:两种仪器线性范围良好(r﹥0.999),RSD﹤1%,回收率在90%~110%,标准物质测定均在定值范围内,结果准确可信。ICP-MS较石墨炉原子吸收光谱仪更为简便快捷,而且可以同时分析多种元素,更具有优势。 相似文献
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超高效液相色谱仪LC-30A和三重四极杆质谱仪LCMS-8050联用快速准确测定豆芽中无根豆芽素的分析方法。样品经适当样品前处理后,用超高效液相色谱分离,三重四极杆质谱仪进行定性定量分析。结果表明:无根豆芽素在0.50~50.00 ng/mL浓度范围内线性良好,相关系数为0.999,仪器检出限为0.01 ng/mL,定量限为0.04 ng/mL。实际样品加标不同浓度所得回收率范围为100.10%~112.20%,精密度RSD%范围为3.22%~6.53%。 相似文献
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The gendered marketing of children’s toys is under considerable scrutiny, as reflected by numerous consumer-led campaigns and vigorous media debates. This article seeks to assist stakeholders to better understand the ethical and scientific assumptions that underlie the two opposing positions in this debate, and assess their relative strength. There is apparent consensus in the underlying ethical foundations of the debate, with all commentators seeming to endorse the values of corporate social responsibility and gender equality. However, the debate splits over three critical points of empirical disagreement: whether gendered toy marketing influences children’s toy preferences or simply reflects boys’ and girls’ fundamentally different interests; whether the effects of gendered toy marketing are negative, neutral or beneficial; and whether a shift to gender-neutral marketing would be economically viable. We assess the three points of disagreement against the available evidence and shared ethical principles underlying the debate, and conclude that current defences of gendered toy marketing fail. 相似文献
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Leah Watkins Robert Aitken Ryan Gage Moira B. Smith Tim J. Chambers Michelle Barr James Stanley Louise N. Signal 《The Journal of consumer affairs》2019,53(4):1396-1420
There is widespread concern about the implications of increased targeting of marketing to children. However, despite the ubiquitous presence of marketing in children's environments, children's actual exposure to the full range of marketing across all media and in multiple settings remains unknown. This article reports on an innovative method of analysis, using data from wearable automated cameras, to objectively document children's marketing exposure across and within settings. Results show children were exposed to an average of 638 marketing encounters per day. The most common form of marketing exposure was to brand labeling, and marketing for food and beverages the dominant product category. This article provides an objective observation of the commercial world of children in a wide range of settings, presenting unique insights and a new analysis method for documenting children's environmental advertising exposure to inform policy decisions about the ethics and practices of marketing to children. 相似文献