共查询到20条相似文献,搜索用时 390 毫秒
1.
海蜇中明矾(铝)质量分数4种测定方法的比较 总被引:3,自引:0,他引:3
铝(Al)元素在海蜇产品中以明矾的形式存在,Al在人体内累积会对健康造成危害。当前海蜇中明矾(Al)质量分数测定方法较多,各种方法的操作及检测灵敏度均存在差异。研究比较了水煮滴定法、原子吸收光谱法、比色法和酸煮滴定法4种不同方法的检测效果,对各种方法中的前处理现象差异、检测结果、检测方法的准确度和精密度及方法的可操作性等方面进行对比。结果表明,酸煮滴定法前处理只需6min,煮沸后过滤速度快,其测定结果与原子吸收光谱法的结果相近。酸煮滴定法、比色法和原子吸收光谱法回收率介于103.81%~107.60%,平均回收率为104.70%,符合分析要求。对比各种测定方法的优缺点得出,酸煮滴定法操作简便快捷、花费少,适用于生产工厂及检测机构日常检测。 相似文献
2.
分光光度法测定水产品中甲醛含量的研究 总被引:3,自引:0,他引:3
研究采用乙酰丙酮分光光度法测定水产品中的甲醛含量,对样品的前处理过程进行了比较系统的探讨,确定了比色测定参数,并对其用于快速测定水产品中甲醛含量的可行性进行了讨论。实验结果表明,用冰浴浸泡法前处理样品时,最佳浸泡时间为10min,样液pH值用100g·L^-1氢氧化钾溶液调至6;沸水浴中最佳显色时间为3min,比色波长为412nm;当甲醛含量在0~2.5μg·mL^-1范围内时,该方法具有很好的线性关系(R^2=0.9998);与蒸馏法前处理样品相比,该方法的加标回收率比较高,在89.50%~94.25%之间,而前者为64.17%~76.92%;该方法的RSD(%)为2.93%,样品的最低检出浓度为0.9mg·kg^-1。 相似文献
3.
4.
5.
中国海洋科学代表团于1978年对美国海洋科学工作进行了参观考察。据介绍,美国对海洋经济动、植物的人工养殖,过去主要在水产部门进行一些研究工作,研究的种类也较少。动物人工养殖的总产量只有65000吨,占美国进口水产品的3%,占美国水产品生产总量的2%。目前,美国传统水产资源的产量已经达到了最高的可捕量,但需要量逐年增加。 相似文献
6.
7.
8.
9.
10.
《中国渔业质量与标准》2015,(4)
采用液相色谱法和可见分光光度法分别测定水产品中组胺的含量,比较了这两种检测方法测定结果的差异性,结果发现可见分光光度法的检测值比液相色谱法高。根据可见分光光度法的显色反应原理,研究了尸胺、腐胺、亚精胺和酪胺4种水产品中常见的非挥发性生物胺与偶氮试剂的显色反应,发现4种生物胺在480nm处都有一定吸光度,这会对组胺的检测结果产生不同程度的影响;其中酪胺对检测结果的影响最大,其吸光度达到了同浓度组胺的70%左右,而且生物胺的浓度越高对组胺检测结果产生的影响也越大。这4种生物胺是水产品中常见的胺类物质,采用可见分光光度法测定组胺含量时,其存在往往会导致检测结果偏高。因此,为保证水产品中组胺检测数据的准确性,尽量选择使用液相色谱法进行检测。本研究为水产品中组胺定量检测方法的选择及检测结果分析提供数据支撑。 相似文献
11.
近年来因文蛤(Meretrix meretrix)异地移养频繁造成遗传背景不明, 对种质保护和选择育种工作造成了影响, 进而阻碍了产业的持续发展。为挖掘不同海域文蛤群体的种质资源状况, 评估子代群体的选育潜力, 本实验采用聚类分析、主成分分析、判别分析等多元统计方法以及 SSR 标记手段对 5 个不同海域文蛤群体及江苏子三代文蛤选育群体的亲缘关系进行联合分析。结果显示: (1)日本三重文蛤群体的表观性状与所供试的 5 个我国的文蛤群体都存在着显著性差异(P<0.05), 主成分分析及判别分析结果亦验证了该结果, 并且日本文蛤与我国文蛤的遗传差异也较大(Fst>0.1); (2)多元统计方法和 SSR 标记聚类分析所得结果一致, 江苏南通文蛤群体与其选育后代江苏子三代文蛤群体先聚为一类, 之后与广西文蛤聚为一类, 采自渤海湾的山东文蛤则与辽宁文蛤聚为一类, 之后我国文蛤聚类后与日本文蛤群体聚在一起。但通过 SSR 标记手段对个体进行鉴定的准确率(91.3%)高于多元统计方法 (62.78%); (3)江苏子三代文蛤选育群体与原种相比, 在遗传多样性水平上均无显著性差异(P>0.05)。本研究表明日本文蛤与我国文蛤的差异在形态特征和遗传水平上均较为明显; 并分析了不同方法分析结果存在差异的原因, 阐述了两种方法进行联合分析的必要性; 表明了异地移养对我国文蛤种质造成的影响, 并提出了相应保护措施; 进行了将远缘种群进行杂交选育的设想; 亦通过微卫星分子标记手段证明了江苏文蛤子代群体具有继续选育的潜力, 验证了通过群体选育途径培育文蛤新品种的可行性。 相似文献
12.
本研究采用核酸适配体的单链DNA浓度来表征其亲和力,通过测定核酸适配体与靶细菌哈维氏弧菌(Vibrio harveyi)结合后ssDNA的浓度,来研究该核酸适配体的亲和特异性和亲和常数,并通过荧光显微镜法对其亲和特异性进行验证。结果显示,采用单链DNA浓度法测得该核酸适配体对靶细菌哈维氏弧菌的亲和力是非目标菌的15.2倍以上;荧光显微镜直接观察发现只有靶细菌能较好结合有荧光标记的核酸适配体,并呈现明显荧光;荧光阻断法发现靶细菌和非靶细菌都未呈现明显荧光,证明了该适配体有较好的亲和特异性,也进一步验证了单链DNA法的测定结果。在亲和常数的测定方面,利用单链DNA浓度法测得该核酸适配体的亲和常数K_d=(33.70±7.83) nmol/L,相应的拟合系数为R~2=0.960,有较好的准确性和可靠性,说明采用单链DNA浓度法来测定适配体的亲和力和亲和常数是可行的。 相似文献
13.
微卫星标记在长牡蛎三倍体鉴定中的应用 总被引:1,自引:1,他引:0
为开发一种简单有效的倍性检测方法对长牡蛎三倍体诱导结果进行准确评估,本实验采用细胞松弛素B抑制第二极体释放诱导产生长牡蛎三倍体,选用7个微卫星位点扩增基因组DNA,通过亲子代基因分型进行倍性检测,检测结果采用流式细胞仪加以验证,以评估微卫星标记倍性检测的准确性。另外,本研究探讨了准确鉴定倍性所需的微卫星标记数量与微卫星—着丝粒重组率(y)之间的关系,以期为其他物种采用分子标记进行倍性检测提供理论依据。结果显示,细胞松弛素B诱导产生的115个长牡蛎子代经7个微卫星位点鉴定得到40个三倍体,与流式细胞仪检测结果一致,准确率达到100%,7个微卫星位点的(1-y)的乘积为0.005。随机挑选6个位点,也可鉴定出所有三倍体,(1-y)的乘积为0.005~0.042。研究表明,本研究中开发的微卫星标记可以简单高效地鉴定长牡蛎三倍体,微卫星位点的(1-y)的乘积小于0.005,倍性检测的准确率可达100%,采用微卫星标记进行倍性检测对于加速长牡蛎三倍体育种进程具有十分重要的意义。 相似文献
14.
We have employed both common and novel methods to measure the amount of silver released from nanoparticle composite packaging. Forty-eight packages of green tiger prawns (Penaeus semisulcatus) were prepared: 24 packages with nanoparticle packaging and 24 packages without nanoparticle packaging. The normal shelf life of P. semisulcatus in the refrigerator is 1–2 days, and we therefore we tested the packages after 0, 1, 2, 3, 4, 5 and 6 days. We measured the diameter of the inhibition zone of the targeted microorganisms (Escherichia coli and Staphylococcus aureus) and examined scanning electron microscopy (SEM) images, using both titration and migration methods, to measure the amounts of silver nanoparticles released. Compared to the standard amount allowed by standard 13737-3 of the National Information Standards Organization, our results indicated the superior sensitivity of the titration method over the migration method in terms of determining the remaining amount of nanoparticles (P < 0.05). The evaluation of SEM images indicated the homogeneity of the surface of the silver nanoparticle packaging and the even exchange capacity of titanium dioxide. The average size of the nanoparticles in the packaging films was determined to be 30–48 nm. The diameter of the inhibition zone in the silver nanoparticle, measured at the six time points, was significantly larger than that seen with other packaging, except for the phosphomycin and penicillin antibiogram disks (P < 0.01). The sensitivity of the titration method using the titration equipment was significantly higher than that of the migration method (P < 0.05). The findings indicate that nanoparticle packaging decreased the microbial count and enhanced the shelf life of P. semisulcatus, leading us to recommend the utilization of silver nanoparticle packaging. 相似文献
15.
Abdolsamad K Amirkolaie Saber A El-Shafai Ep H Eding Johan W Schrama & Johan A J Verreth 《Aquaculture Research》2005,36(6):578-585
The need for unbiased digestibility estimation has led to the development of a number of faeces collection methods. However, there is still a large variation in apparent digestibility coefficient (ADC) of diet/ingredients between these methods. This study investigated the impact of dietary quality on ADC and faeces recovery measurements obtained by two faecal collection methods (Choubert and settling tank). The fish were fed five diets: a control diet as high‐quality diet, two levels of dried duckweed (20% and 40%) and two levels of fresh duckweed (20% and 40%), which were added to the control diet, as low‐quality diets. Apparent digestibility coefficient estimates were highly correlated (r>0.95) between both faecal collection methods. For all diets the ADC estimates were higher when using settling tanks compared with Choubert collectors. For the control diet differences in ADC between two collectors were small, but by inclusion of duckweed these differences increased. The recovery percentage of faeces was not correlated between both faecal collection methods (r=0.22, P=0.41). The estimated recovery percentage of faeces by settling tanks was about three times higher than by Choubert. In conclusion, the differences in ADC and faeces recovery measured by two faecal collection methods depend on diet quality. 相似文献
16.
17.
18.
J. P. Doody 《水产资源保护:海洋与淡水生态系统》1992,2(3):275-283
1. New land has been ‘won’ from the sea by the process of embankment for centuries. It is perhaps not surprising, given the long term commitment to the protection of the land so created, that current works are concerned largely with reinforcing the existing line of sea defence. 2. Those concerned with nature conservation have likewise in the past, expended considerable energy in trying to protect natural and semi-natural habitat from destruction and exploitation by man. This has included land claim and associated sea defence works. 3. This paper examines these two perceptions of ‘coastal protection’ and suggests a more enlightened approach which accepts change as an important part of coastal development, and provides a more positive way forward. Those concerned with sea defence and nature conservation may have to accept that protection of the current line of sea defence or existing coastal habitats, may not be the best option in all cases. 相似文献
19.
本实验主要比较了离子霉素、电脉冲2种方法激活牛、羊体外成熟卵母细胞的效率。2种激活方法中,牛胚胎卵裂率无显著差异(90.61%VS94.40%,P>0.05),而离子霉素激活胚胎的囊胚发育率极显著高于电激活方法(12.3%VS2.4%,P<0.01)。2种方法对羊的胚胎的研究中,羊胚胎卵裂率无显著差异(72.4%VS77.4%,P>0.05)。但是离子霉素激活胚胎的囊胚发育率显著高于电激活方法(3.67%VS10.4%,P<0.05)。本实验中还比较了用化学激活(离子霉素)激活牛体外成熟卵母细胞后,用SoFaa体系培养,换液与不换液对孤雌激活胚胎体外发育的影响。结果表明:在第四天不换液的胚胎卵裂率和囊胚率极显著高于换液的胚胎(11.64%VS3.49%,P<0.01)。 相似文献
20.
两种耳石分析法在鲚属种间和种群间识别效果的比较研究 总被引:6,自引:0,他引:6
采用耳石传统形态测量法和傅里叶形态分析法,对281尾2龄长江凤鲚(Coilia mystus)和刀鲚(C.nasus)个体的矢耳石形态学作了分析,结果表明,采用传统的耳石形态测量法对凤鲚与刀鲚种间的正判率达90.9%,但2个刀鲚生态型种群之间的判别成功率仅为76.9%。而运用傅里叶耳石形态分析法,凤鲚和刀鲚物种间的识别率高达100%,2个刀鲚生态型间的识别率也提高至86.8%。可见,两种耳石形态分析法对鲚属种间的识别效果均很好,但对种群分析而言,傅里叶形态分析法可以取得更好的识别效果。 相似文献