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[目的]建立了葡萄酒中中恶霜灵残留量的液相色谱-串联质谱分析方法。[方法]样品直接注入液相色谱仪,经AgilentXDB-C18色谱柱分离,以0.1%甲酸水溶液和乙腈为流动相进行梯度洗脱。以电喷雾正离子(ESI+)模式电离,多反应监测(MRM)模式检测,基质匹配标准溶液外标法定量。[结果]恶霜灵2-400μg/L范围内呈线性相关,相关系数(r)均大于0.999;其定量限为5μg/L。葡萄酒样品在5、10和20μg/L添加水平时,恶霜灵的回收率范围分别为91.5%-111.2%,相对标准偏差(RSD)分别为6.2%-8.6%,可以满足葡萄酒中恶霜灵残留量的检测需要。[结论]本方法无需前处理,灵敏度高,选择性好,同时定性定量,对葡萄酒中恶霜灵含量的测定及评估更为准确。 相似文献
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1前言
农药残留严重导致损害人类的健康.为此,很多国家对于高毒高残留农药作出了最严格的限制.
蔬菜中有机磷农药残留的检测,主要有气相色谱法(GC)[1-3]和生物技术法.生物技术法包括免疫法[4],生物传感器法[5,6]及植物酯酶片法[7],而免疫法及生物传感器方法目前还未商品化,植物酯酶片法虽然有市售试剂盒,而且检测快速,简便,可其灵敏度不高,通常只能检测残留量在2mg/kg以上的样品,因此不能满足低残留量(≤0.05mg/kg)检测要求. 相似文献
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[目的]建立快速、准确地测定中药材中汞和砷含量的方法.[方法]微波消解处理样品,流动注射-氢化物发生-原子吸收法检测.[结果]汞在0.002 mg/L~0.02 mg/L浓度范围内线形良好,检出限为0.0004mg/L;砷在0.02 mg/L~0.16 mg/L浓度范围内线形良好,检出限为0.001mg/L,相关系数均大于0.99990;汞的回收率在85.0%~93.8%,砷的回收率在89.4%~102.0%,相对标准偏差分别为5.5%和4.1%.[结论]该方法省时、节能、准确度高. 相似文献
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为了研究污水中苯酚的降解方法,以分析模拟苯酚废水作为研究对象,分别在紫外光解、生物氧化和紫外光解/生物氧化同步耦合三种方法下进行间歇降解,结果表明:在紫外光解和紫外光解/生物氧化同步耦合方法处理苯酚时,苯酚的初始浓度越高,苯酚的降解率越低,但苯酚的降解速率越高。高浓度的苯酚对微生物有抑制作用,苯酚初始浓度为200mg/L时,生物降解的速率为50.9mg/(L·h),而苯酚初始浓度为300mg/L,400mg/L和500mg/L时,苯酚的降解速率只有39.1mg/(L·h),37.9mg/(L·h)和32.8mg/(L·h)。紫外光辐射能够降低其抑制性,苯酚初始浓度为300mg/L,400mg/L和500mg/L时苯酚的降解速率达到了43.9mg/(L·h),61.0mg/(L·h)和67.2mg/(L·h);同时也提高苯酚的矿化程度,COD去除率都达到了50%以上,最高达到了95%。 相似文献
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[目的]对GB/T19857-2005的前处理方法进行优化,使其更适合实验室使用。[方法]称取3.00g样品,用乙腈沉淀蛋白,乙酸铵缓冲液作为辅助提取试剂,C18散装填料吸附油脂,二氯甲烷作为极性改进剂,经定量提取上清液蒸干后,用乙腈-5mmol/L乙酸铵(含0.1%FA)(1:1)洗脱、定容,过0.20μm滤膜后上机测定。[结果]4种目标物在3min内全部出完峰,检出限0.5μg/kg,在0.5-10μg/kg范围内线性关系良好(r≥0.999),回收率89.3-113.3%,RSD 1.7-8.7%。[结论]该方法具有操作简单、检测速度快、结果准确、检测成本低等特点,完全符合实验室检测的需要,特别适用于拥有大批量样品的实验室。 相似文献
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[目的]建立了气相色谱-质谱法测定葡萄中扑灭津残留量的分析方法。[方法]样品经乙腈提取,盐析,弗罗里硅土固相萃取柱净化,气相色谱-质谱测定,选择离子监测模式,外标法定量。[结果]在0.1-4mg/kg的范围内线性良好(r〉0.99),在0.05-0.25mg/kg的添加水平范围内,平均回收率为90%-100%,相对标准偏差(RSD)为4.7%-7.4%,检出限(LOD)为0.025mg/kg,测定低限(LOQ)为0.05mg/kg。[结论]该方法简便、快速、灵敏、准确、低成本、耐用,适合葡萄中扑灭津残留量的测定。 相似文献
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[目的]研究Roundup Ready大豆的Lectin、CaMV35S、NOS和CP4EPSPS等被检测基因的RT-PCR定性范围。[方法]用CTAB法提取DNA,对Lectin、CaMV35S、NOS和CP4EPSPS等被检测基因的检测条件进行了优化,确定了被检测基因在相同RT-PCR条件下的定性范围。[结果]研究发现,不同被检测基因在相同RT-PCR条件下的浓度检出范围不同。Lectin为0.05~792mg/L,CaMV35S为0.25~792mg/L,NOS为0.25~396mg/L,CP4EPSPS为0.05~1980mg/L;共同的方法检出限LOD为5ng,体系浓度范围为0.25~396mg/L。[结论]确定了Roundup Ready大豆被检测基因的定性范围和检出限,可应用于大豆中相关基因的检测。 相似文献
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在微波辐射下,1-甲基咪唑分别与有机卤盐(1-溴丙烷,溴代正丁烷,1-溴己烷)在80℃回流加热10min,可制得咪唑类离子液体的中间体溴代1-丁基-3-甲基咪唑([BMIm]Br),溴代1-丙基-3-甲基咪唑([PMIm]Br),溴代1-己基-3-甲基咪唑([C6MIm]Br),进一步与HPF6在室温搅拌反应4h,制得憎水性的咪唑类离子液体[BMIm]PF6,[PMIm]PF6,[C6MIm]PF6。对这3种离子液体及其在不同有机溶剂丙酮、甲醇、乙酸乙酯中的电导率的进行测定,发现离子液体的电导率受咪唑上取代基种类、溶剂种类、浓度和温度的影响,取代基的链越长,体积越大,离子液体的电导率越小?并且随温度升高和浓度的增大,离子液体的电导率也增大。 相似文献
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止咳水试样用50%甲醇水溶液超声提取,经有机滤膜过滤后,利用液相色谱-串联质谱(LC-MS/MS)进行检测,建立了止咳水中31种毒品成分的快速测定方法。分析物采用电喷雾离子源(ESI),正离子多反应监测(MRM)模式检测,外标法定量。可待因等28种组分在2~50μg/L浓度范围内线性关系良好,检出限在0.2~2μg/L范围内,在10~50μg/L添加浓度范围内回收率为80.1%~109%;大麻酚、四氢大麻酚、大麻二酚物质在10~200μg/L浓度范围内线性关系良好,检出限均为4μg/L,在50~250μg/L添加浓度范围内回收率为81.2%~109%;化合物的相对标准偏差(RSD)为1.7%~14.4%。所建立的方法灵敏度高,简便快捷,稳定性好,可用于止咳水中毒品类物质的定性鉴定及定量分析,为该类物质的快速检测提供技术支撑。 相似文献
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Many purchase decisions take place in social relationships, and yet few studies have specifically investigated couples’ purchase decisions made during shopping about products for later joint consumption. We hypothesize that romantic partners purchase more when they shop together than individually and that this effect is strong for vice products, particularly those without an organic label. For our empirical study, we asked romantic partners shopping together in a real-life context to make purchase decisions together or individually (our main experimental condition) in a self-programmed web store that offered 88 product variants (differing in category [vice/virtue] and labeling [with/without organic label]). Participants then filled out an online questionnaire on site. Results of a sequence of nested generalized linear models show that making purchase decisions together increases purchase amount (number of items selected) and purchase value (quantities selected multiplied by the corresponding willingness to pay), especially for vice products without organic labeling. In a second study, we benchmark these effects by comparing them with the effects of individual decision making and varying consumption mode (joint vs. individual consumption), using data from an online survey that followed the same structure as the main study. These effects, again estimated through generalized linear models, are negligible. Our findings strongly support the “accomplice” (rather than the “minder”) role of romantic partners in shopping. Therefore, retailers should target couples, encourage them to shop together, and emphasize joint consumption as a shopping goal. 相似文献
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[目的]利用DNA条形码技术对口岸截获的形态特征破坏严重的未知蚊类进行种类鉴定。[方法]提取从荷兰进口的废纸中截获的一头形态严重破坏的蚊类的基因组DNA。采用无脊椎动物线粒体细胞色素氧化酶I(COI)的通用引物LCO1490和HCO2198扩增目的片段。然后纯化、克隆测序、序列分析、与BOLD中的序列进行比对。[结果]该未知蚊类的DNA条形码序列与BOLD中环带林蚊(Sylvicola cinctus)的序列相似性超过99.8%;并与原产地专家交流确认截获的蚊种为环带林蚊。经科技查新,确认为首次截获的国内未见分布蚊种。[结论] DNA条形码能克服传统物种鉴定依靠完整的外部形态的局限,有效提高外来物种的种类鉴别能力,大大缩短检测周期,降低外来物种对我国生态和公共卫生安全的危害。 相似文献
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烃类充注对储层的影响长期存在争议。文章采用薄片观察、电子显微镜等手段.系统研究了烃类充注后储层的成岩作用变化,系统阐述了烃类充注对储层质量的影响:(1)在石英含量高的石英砂岩中,烃类充注阻碍了离子之间的交换,抑制石英胶结物的生成,对储层较为有利;(2)在长石和岩屑含量高的长石岩屑砂岩或者岩屑砂岩中,烃类充注后会溶蚀其中的易溶矿物长石、岩屑等.同时这些溶蚀作用会导致高岭石的沉淀和强化石英加大的产生,降低储层质量。 相似文献
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弧菌显色培养基(ChromID Vibrio)对霍乱弧菌检测效果的探讨 总被引:1,自引:0,他引:1
[目的]探讨梅里埃弧菌显色培养基(简称ChromID Vibrio)对霍乱弧菌的检测效果。[方法]通过ChromID Vibrio弧菌显色培养基同硫代硫酸盐-柠檬酸盐-胆盐-蔗糖(简称TCBS)琼脂培养基进行比对,采用阳性菌株直接平板计数、人工污染样品和实际样品检测的方法,对ChromID Vibrio的灵敏性、特异性和检测效果进行了评价。[结果]ChromID Vibrio弧菌显色培养基上霍乱弧菌典型菌落是蓝绿色。阳性菌株直接平板计数及人工污染试验均表明ChromID Vibrio平板的敏感性均比TCBS平板高。对采集的300份实际样品进行检测,都未检出霍乱弧菌。[结论]ChromID Vibrio具有较好的灵敏性、特异性,能提高霍乱弧菌检测效率。 相似文献
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采用水-甲醇(1:1,V/V)溶液超声波辅助萃取,建立了同时快速测定贝类中砷胆碱、砷甜菜碱、亚砷酸、砷酸和4-氨基苯胂酸等5种砷形态的高效液相色谱-电感耦合等离子体质谱(HPLC-ICP-MS)分析方法。对萃取溶液浓度、超声波辅助萃取温度和时间等条件进行了优化。选用Hamilton PRP-X100阴离子分析柱,以50 mmol/L碳酸铵-甲醇(99:1,V/V)溶液为流动相,进行梯度洗脱对5种砷形态分离,并优化了质谱测试条件。试验结果表明,5种砷形态达到很好的分离效果,在质量浓度为0~100μg/L的范围内与其对应的峰面积均具有良好的线性关系,线性相关系数r2均大于0.999,检出限在0.2~0.60μg/L之间,两水平样品加标回收率在90.5%~103.5%之间,方法的精密度在1.6%~4.2%之间。 相似文献
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[目的]利用DNA条形码技术快速准确鉴定从入境船舶上截获的未知双翅目昆虫蛹。[方法]将截获的5只蛹,1只蛹直接冷冻,4只孵化出成蝇;对蛹、蛹壳及孵化出的成蝇进行拍照留档。分别从蛹、蛹壳和孵化成蝇中提取基因组DNA;采用动物DNA条形码通用引物(LCO1490和HCO2198)扩增目的片段,并进行纯化、克隆测序和序列分析,与NCBI及BOLD中的序列进行比对,构建NJ树;对孵化成蝇进行形态鉴定。[结果]所检测的蛹、蛹壳以及孵化成蝇的DNA条形码序列与NCBI和BOLD中大头金蝇(Chrysomyia megacephala)的序列相似度达100%;孵化成蝇与大头金蝇的形态特征相符。[结论]根据测定结果,判定截获的未知双翅目昆虫蛹为大头金蝇的蛹;证明DNA条形码技术是一种鉴定未知昆虫蛹的有效手段。对于口岸截获的外来未知昆虫蛹、成虫残肢甚至蛹壳均可直接采用DNA条形码技术进行种类鉴定,大大缩短鉴定周期。 相似文献
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This paper aims to reveal consumer perceptions of organic food with a special emphasis on the labelling of organic products. The objectives were to find out, whether or not a significant difference between men´s and women´s perception existed. Two groups (88 subjects in the experimental group, 59 subjects in the control group) were shown various food labels; with organic product labelling (experimental) and without (control). Results suggest the importance of organic labelling using eye-tracking data and additional in-depth interviews to discover the importance of the labelling for participants. Based on eye-tracking data, the greatest visual attention was paid to product brand, graphic elements and organic labelling claims with additional information, such as a quantity or flavour, also being important. Additional in-depth interviews discovered that labelling, particularly of the origin, is important for most consumers. Contrary to what was expected, eye-tracking showed very little difference in the perception of organic product labelling based on gender. Although organic food is being purchased by more people, 50% of participants mentioned, during interviews, that they buy organic food only occasionally. The combination of eye-tracking and in-depth interviews shows that organic product labelling can play a role in decision-making, but regardless 27% of participants do not care about the organic quality labels or don’t pay attention to them. 相似文献
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This study examined the effect of definitions for organic and natural on willingness to pay a premium for organic over natural chicken. Data were collected using surveys and experimental auctions that were conducted before and after information was presented. Before information, approximately two‐thirds of participants inaccurately equated the requirements of natural with those for organic. After information, nearly 50% increased their premium, while 30% decreased their premium. Logistic regression results showed that consumers who had overestimated the requirements for natural were most likely to have an increased premium after information, with significantly higher bids for organic. For those who decreased their premium after information, awareness of consuming genetically modified (GM) foods was a key variable. The non‐genetically modified (non‐GM) requirement of organic appears to be of low value to some consumers. Overall, consumer confusion regarding organic and natural standards may be having substantial impacts on the two markets. 相似文献