共查询到20条相似文献,搜索用时 62 毫秒
1.
考马斯亮蓝-G250和牛血清蛋白反应生成蓝色络合物,蛋白质浓度与产物的颜色深度存在对应关系.在误差传递规律基础上利用手机比色法,考察了光照和手机类型等影响取样的外在因素,建立了蛋白质含量测定的新方法.实验表明,在最优测定条件下,间接测量值XB与蛋白质浓度在1~7 μg/mL范围内存在明显的线性关系,标准样品测定的相对标准偏差为3.47%(n=8),检出限为0.67 μg/mL.对花生、葵花籽、南瓜子等坚果的水溶性蛋白质进行加标回收实验,回收率在100.3%~107.5%之间,该方法简便快捷、灵敏度高、回收率好,可用于坚果中水溶性蛋白质含量的测定. 相似文献
2.
黄露 《井冈山大学学报(自然科学版)》2014,(2):23-26
首次采用非水毛细管电泳法对两种苏丹红染色剂-苏丹红I与苏丹红II进行了分离检测。考察了电泳介质、背景电解质、SDS浓度对分离的影响。当运行缓冲液为100 mmol/L乙酸钠+35 mmol/L SDS的乙腈/甲醇(6:4,v/v)混合溶液时,两种苏丹红化合物能够在15 min内达到基线分离。各组分的峰面积与待测物浓度在0.01~0.5 mg/mL范围内呈良好的线性关系,检测限均为0.005 mg/mL。最终检测到辣椒样品中含有苏丹红II浓度为3.040 mg/g,苏丹红I与苏丹红II在加标辣椒样品中的回收率分别为94.68%和81.00%。 相似文献
3.
4.
建立超声提取-液相色谱质谱法同时测定苏丹红Ⅰ、苏丹红Ⅱ、苏丹红Ⅲ、苏丹红Ⅳ以及罗丹明B五种食品非法添加染料的方法。辣椒制品以正己烷为提取溶剂,超声波提取15min,乙腈饱和正己烷溶液去油脂,乙腈定容。采用LC-MS/MS正离子扫描测定食品非法添加物罗丹明B和4种苏丹红。标准加标回收试验,罗丹明B添加浓度分别为2,4,8μg/kg,苏丹红Ⅰ~Ⅳ添加浓度为:10,20,30μg/kg,平均回收率为90.3%~94.3%,相对标准偏差(RSD)2.0%~4.9%。本方法5种非法添加染料的检出限罗丹明B为1μg/kg,苏丹红Ⅰ~Ⅳ检出限均为5μg/kg。该方法简便、快捷、大大降低了前处理时间,适合进行批量样品的测定。 相似文献
5.
研究了快速法测定COD的准确性与溶液浓度的关系,分析了不同催化剂及反应温度对测定准确性的影响.水样COD质量浓度在18.14~54.42 mg/L时,绝对误差为0~1 mg;在较高质量浓度(72.56~390.53 mg/L)时,绝对误差为1~10 mg;当增加到585.80~1 952.65 mg/L时,绝对误差增加到10~30 mg.而相对误差值在以上3种质量浓度情况下为0.8%~5.1%.反应温度在140~165 ℃时,相对误差为0.9%~1.0%.用快速法测定了工业废水中的COD值. 相似文献
6.
火焰原子吸收光谱法测定蒸馏酒中微量铅的检验方法与卫生部卫生标准规定的双硫腙比色法相比,操作简单、快速,稳定性好,回收率高。本法灵敏度为0.24mg/L,若取50ml酒样测定最低检出浓度为0.02mg/L,配制混合酒样和市售瓶装蒸馏酒实测结果均与双硫腙比色法符合良好。 相似文献
7.
以玻碳电极为指示电极,用线性扫描伏安法测定水杨酸,从而间接测定阿司匹林.在硫酸-硫酸钾底液中,水杨酸在玻碳电极上产生一灵敏的氧化峰,峰电位为1.16 V;在4.0×10-5mol/L~8.0×10-3mol/L浓度范围内水杨酸与峰电流呈良好线性关系,最低检测浓度为2.0×10-5 mol/L.对阿司匹林肠溶片和复方乙酰水杨酸进行了测定,测定值分别为51.33 mg/片和221.3 mg/片, 回收率分别为91.3%,90.7%, RSD为2.1%,0.7%. 相似文献
8.
毛细管电泳-电化学发光法测定盐酸西替利嗪的含量 总被引:1,自引:0,他引:1
采用毛细管电泳-联吡啶钌电化学发光法测定了盐酸两替利嗪的含量.讨论了联吡啶钌浓度、检测电位、磷酸盐缓冲液浓度和pH值、进样时间和进样电压等实验条件对盐酸西替利嗪分离检测的影响.在优化实验条件下,盐酸西替利嗪在10~140 mg/L范围内呈良好线性(相关系数0.997 6);检出限为2.0 mg/L(S/N=3).本法可直接用于尿液中盐酸西替利嗪含量的测定,回收率为96.9%~98.7%. 相似文献
9.
建立了用单柱阴离子色谱测定地表水中NO-3的方法。采用NJ-SA-4A阴离子交换柱、0.35mmol/L NaCO3+0.05mmol/LNaHCO3混合溶液为流动相、电导检测器在5min内完成NO-3的测定。NO-3浓度在0.1~50 mg/L范围内与峰面积线性关系良好,线性回归方程为ΔS=1.14×10-4C+0.192,相关系数为0.9999,方法检出限为0.05mg/L,加标回收率为99.8%~102.3%,方法简便实用,用于地表水分析,所得结果令人满意。 相似文献
10.
建立了免预处理测定水样中硫化氢浓度的快速简便方法.该法利用硫化氢的可气化、可透过气液分离膜的特征使之与复杂基底分离,基于亚甲基蓝比色法原理进行测定.自制PVC采样装置,内装显色剂(对氨基二甲基苯胺与硫酸高铁铵的混合液),以聚四氟乙烯气液分离膜封口;将该装置投入水样中,水中的硫化氢透过分离膜扩散进入装置并与显色剂反应;20 min后用分光光度计测定吸光值.利用标准曲线即可计算水中硫化氢的浓度,亦可通过目视比色法半定量快速检出,测定范围为0.05~10 mg(S2-)/L.本法简单、方便、低成本,省却了繁琐的预处理操作步骤,基底干扰小,可直接测定浑浊水样.本法有望发展成现场及原位的测定方法,用于低浓度硫化氢的定性和半定量快速分析. 相似文献
11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness. 相似文献
12.
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly. 相似文献
13.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。 相似文献
14.
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well. 相似文献
15.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation. 相似文献
16.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death. 相似文献
17.
Miao Maosheng 《华南师范大学学报(自然科学版)》2014,(6)
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula- 相似文献
18.
Yang Weitao 《华南师范大学学报(自然科学版)》2014,46(6):137-138
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re- 相似文献
19.
Bernard Kirtman 《华南师范大学学报(自然科学版)》2014,(6)
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that 相似文献
20.
《上海师范大学学报(自然科学版)》2014,(5):550
<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with 相似文献