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目的对QuEChERS-气相色谱-串联质谱法测定结球甘蓝中甲基毒死蜱农药残留进行不确定度评估。方法运用气相色谱-串联质谱法对结球甘蓝中甲基毒死蜱残留量进行测定,通过建立数学模型,分析测定过程的主要不确定度来源,对各个分量进行评估。结果不确定性的主要来源是标准溶液的配制、工作曲线的拟合及加标回收率引入。当甲基毒死蜱的残留量为0.041 mg/kg时,扩展不确定度为0.003 mg/kg (k=2)。结论该方法适用于气相色谱-串联质谱法测定甲基毒死蜱残留量的不确定度分析,可为农药残留测量结果的准确性提供科学可靠的依据。 相似文献
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目的探讨毒死蜱在茶园的使用安全性。方法采用室内检测和田间试验方法,对45%毒死蜱乳油在茶叶上的残留消解动态进行研究。样品采用含体积分数1%乙酸的乙腈溶液超声提取,分散固相萃取净化,气相色谱电子捕获法测定。结果在0.005~2.0 mg/L范围内,毒死蜱的质量浓度与其峰面积呈良好的线性关系,相关系数大于0.9990;添加浓度为0.01、0.2和1 mg/kg时,毒死蜱在茶叶中的平均回收率为81.7%~110.7%,RSD小于10%,检出限、定量限分别为0.003 mg/kg、0.01 mg/kg。施药剂量为有效成分540~1080 g/hm2时,毒死蜱在茶叶上的残留量与施药剂量密切相关,施药后初期残留量迅速降低,而后平缓下降,消解动态符合一级动力学反应模型,半衰期为3.78 d~4.16 d,施药后21 d,残留量小于0.1 mg/kg。结论毒死蜱为适于在茶园使用的农药品种,参照欧盟茶叶上毒死蜱的最大残留限量标准(MRL),45%毒死蜱乳油按常规方法喷雾,制剂有效成分用量不超过1080 g/hm2,施药1次,安全间隔期大于21 d,在茶叶上的残留是安全的。但由于毒死蜱在茶树上尚未登记,因此不建议在茶园中使用。 相似文献
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番茄、辣椒、茄子中甲基毒死蜱残留量测定 总被引:1,自引:0,他引:1
采用高效液相色谱-二极管阵列检测器对番茄、辣椒和茄子中甲基毒死蜱残留量进行测定。样品用乙腈提取后,经Carb/NH2固相萃取小柱净化,用C8液相色谱柱、二极管阵列检测器,对甲基毒死蜱残留量的测定可取得满意的结果。该方法样品平均加标回收率为80.7%~92.4%,相对标准偏差为1.1%~4.6%;蔬菜中甲基毒死蜱检出下限为0.02mg/kg。 相似文献
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目的 建立气相色谱法检测椰子汁或复原椰子汁中乙基麦芽酚、香兰素、甲基香兰素、乙基香兰素和椰子醛的分析方法。方法 取适量的椰子汁或复原椰子汁样品, 使用硅藻土固相萃取柱净化提纯, 使用乙酸乙酯作为洗脱剂洗脱, 气相色谱法检测, 外标法定量。结果 乙基麦芽酚在5~100 μg/mL范围内有较好的线性关系, 检出限为2 mg/kg, 定量限为6 mg/kg, 回收率为88.4%~90.6%, 相对标准偏差为1.8%~5.2%; 香兰素、甲基香兰素和乙基香兰素在2~100 μg/mL范围内有较好的线性关系, 检出限为1 mg/kg, 定量限为3 mg/kg, 回收率为80.9%~90.7%, 相对标准偏差为1.8%~5.2%; 椰子醛在1~100 μg/mL范围内有较好的线性关系, 检出限为0.5 mg/kg, 定量限为1.5 mg/kg, 回收率为86.5%~99.7%, 相对标准偏差为1.8%~5.2%。结论 本方法操作简单, 快速灵敏, 稳定性好, 可作为椰子汁或复原椰子汁中乙基麦芽酚、香兰素、甲基香兰素、乙基香兰素和椰子醛的定量和定性检测方法。 相似文献
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当毒死蜱检出且位于限量值附近,为了能更好地对受检样品进行判定。本研究结合自身实验室的具体操作步骤,参考CNAS-GL 006、计量检定(技术)规范等相关标准,依据GB 23200.113-2018《食品安全国家标准 植物源性食品中208种农药及其代谢物残留量的测定》,采用气相色谱-质谱法测定,外标法定量,对黄瓜中毒死蜱残留量的测定结果进行不确定度评定。结果显示:在0.10 mg/kg添加水平、95%置信区间(k=2)下,毒死蜱的测定结果可表示为:(0.10±0.01)mg/kg;其中标准溶液配制不确定度分量对毒死蜱合成不确定度的贡献最高。可见当黄瓜中的毒死蜱残留量≥0.1 mg/kg且≤0.11 mg/kg时,不能判定为不合格,而是使用误差更小的容量瓶、降低操作员的读数误差、减少移液器使用数量、缩小环境温差后,重新进行测定。 相似文献
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气相色谱-质谱联用结合QuEChERS法快速筛查大米中多种农药残留 总被引:3,自引:0,他引:3
采用Qu ECh ERS方法结合气相色谱-质谱联用建立大米中是否存在敌敌畏、草灭达、氧化乐果、五氯硝基苯、敌稗、甲基毒死蜱、杀螟硫磷、甲基吡啶磷、马拉硫磷、毒死蜱、稻丰散、腐霉利、丁草胺、稻瘟灵、三唑磷、联苯菊酯和溴氰菊酯17种农药的快速筛查方法。样品采用体积分数1%冰乙酸-乙腈提取、无水硫酸镁与氯化钠盐析,经N-丙基乙二胺和十八烷基键合硅胶净化,气相色谱-质谱检测,NAGINATA?软件分析。结果表明:17种农药在大米中检出限为0.002~0.050 mg/kg。在0.05、0.10 mg/kg和0.20 mg/kg添加水平的平均回收率为80%~110%,相对标准偏差为1.7%~12.3%。该方法耗时短,操作便捷、快速且可靠,适合大米中多种农药残留的快速筛查。采用本方法对25份大米样品进行测定,检测出毒死蜱、三唑磷和稻瘟灵3种农药残留,残留量均显著低于GB 2763—2014《食品中农药最大残留限量》规定的限量标准。 相似文献
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高效液相色谱法检测罗非鱼中丁香酚残留量 总被引:1,自引:0,他引:1
目的建立罗非鱼中丁香酚残留量的高效液相色谱分析方法。方法样品采用乙腈为提取溶剂,经超声提取、正己烷脱脂净化2次后,通过高效液相色谱技术检测,外标法定量。结果丁香酚在0.1~10.0 mg/L范围内具有良好的线性关系,相关系数为0.99998;5.00 g样品中丁香酚残留量的检出限为0.03 mg/kg,定量限为0.10 mg/kg;3个添加水平平均回收率为80.5%~101.2%,相对标准偏差为3.38%~5.39%。结论本方法具有操作简便、快速、准确的特点,适用于罗非鱼中丁香酚残留量批量检测。 相似文献
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Microgels are ‘soft’ microscopic cross-linked polymeric particles that are being increasingly exploited in a variety of industries for rheology control, encapsulation and targeted delivery. They are valued because of the ability to tune their functionality to address specific applications in oil recovery, coatings, drug delivery, cosmetics, personal care and foods. Food microgels are typically biopolymer hydrogels in the form of microspheres, nanospheres (also called nanogels), spheroids and fibres. The utilisation of engineered microgels in foods has so far been limited, despite their great potential to address several needs in the food industry, including: satiety control, encapsulation of phytonutrients and prebiotics, texture control for healthier food formulations (e.g. reduced fat products), and targeting delivery to specific areas in the digestive tract. We review the scientific and patent literature on the utilisation and manufacturing methods for producing microgels with an emphasis on micro-hydrogels for food applications. 相似文献
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Joubert and Burns prepared a large number of fractions from the high-sulphur proteins of wool and estimated their molecular weights and amino-acid compositions. Their data have been re-examined in order to look for statistically significant interrelations between amino acids and between the proportion of various amino acids and molecular weight. Statistical analysis of the data is also used to examine the credibility of some hypotheses concerning the mechanism of keratin biosynthesis and to provide further evidence for the existence of families of proteins within the high-sulphur fractions of wool. 相似文献
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《肉类研究》2014,(12)
<正>We are pleased to announce the launch of a new international peer-reviewed journal-Food Science and Human Wellness,ISSN 2213-4530,which is an open access journal,produced and hosted by Elsevier B.V.on behalf of Beijing Academy of Food Sciences.Food Science and Human Wellness is an international peer-reviewed English journal that provides a forum for the dissemination of 相似文献
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《印刷工业》2014,(9):94-95
In the 2014 China(Shanghai)International Printing Week,Director Wang Yanbin released the latest data about development of Chinese printing industry in 2013.According to statistics,in 2013,the total output value of Chinese printing industry exceeded 1trillion Yuan for the first time,reaching 1.03985 trillion Yuan.There were 105,000 printing enterprises in China,employees were 3.415 million.The total asset was 1.06247 trillion Yuan; 相似文献
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The State Council Issued "Directory of Government Approved Investment Projects(2013 Edition)" 下载免费PDF全文
《造纸信息》2014,(8)
正On December 2nd,2013,the State Council issued the notification of"Directory of Government Approved Investment Projects(2013 Edition)"(hereafter referred to as"notification").It is pointed out in the"notification"that in order to further deepen reforms in investment systems and administrative examination and approval systems,simplify administrative procedures and delegate powers to lower levels,earnestly 相似文献
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《纺织机械》2014,(3)
正Among the 1600 exhibitors who take apart in the ITMA ASIA+CITME2014 2/3 are Chinese manufactures.If the numerous figures failed to attract your attention,the increase of quality should draw your focus.To adopt the demand of developing textile machine market,domestic textile machinery enterprises now follow the slogan of"technology drives development"to enhance product competitiveness.Our domestic sellers will showcase product ranging from spinning,weaving,dyeing and printing, 相似文献
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《造纸信息》2014,(8):99-100
On December 24th, 2013, the meeting on the selection of top 10 news of China's paper industry 2013 sponsored by 〈China Paper Newsletters〉 was held in Beijing. The yearly selection of the top l0 news, which began in 2000, has become a brand activity widely recognized in the industry thanks to the support from the authorities at all levels and public participation. 相似文献
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National Development and Reform Commission Issued Announcement for Selection of Major Preliminary Research Projects for the "13~(th) Five-Year Plan" 下载免费PDF全文
《造纸信息》2014,(8):83-84
In Apri Commi major p Plan" (h 2014, the National Development and Reform ssion issued an announcement for selection of reliminary research projects for the "13th Five-Year ereafter referred to as "The Announcement") 相似文献
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《食品科学》2014,(17)
<正>We are pleased to announce the launch of a new international peer-reviewed journal-Food Science and Human Wellness,ISSN 2213-4530,which is an open access journal,produced and hosted by Elsevier B.V.on behalf of Beijing Academy of Food Sciences.Food Science and Human Wellness is an international peer-reviewed English journal that provides a forum for the dissemination of the latest scientific 相似文献
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Koni Grob Margherita Vass Maurus Biedermann Hans-Peter Neukom 《Food Additives & Contaminants》2001,18(1):1-10
Oils and fats used for the production of animal feed can become contaminated with mineral oil material originating from gas oils (C18-C35) or synthetic oils (poly alpha olefins, C25 to beyond C45). An important cause is assumed to be the discharge of waste oils, such as motor oil and hydraulic oils. Mineral oil material was analysed by on-line LC-GC-FID directly in the fat or in a raw extract from animal feed or foodstuffs. In Switzerland in summer/autumn 1999 concentrations in oils and fats for feed production were often found to be between 100 and 1000mg/kg. In the feeds, the average concentration was around 100mg/kg with values ranging up to a maximum of 1000mg/kg; few samples were free of contamination. In animal body fat, the average concentration determined in summer 1999 was 25mg/kg, with a maximum of 150mg/kg, although in samples from December 1999, contamination was substantially lower. In the fat phase of eggs, the average concentration was 30mg/kg, with a maximum of 80mg/kg. Paraffin oil is used for feed production, which may account for part of the contamination problem (e.g. eggs). 相似文献