Results 11 to 20 of about 5,405 (176)

Cloud point extraction coupled with Isooctane back extraction for determination of eight pesticide residues in tea beverages by gas chromatography mass spectrometry [PDF]

open access: yes, 2023
Objective: Rapid determination of organochlorine and pyrethroid pesticide residues in tea beverages. Methods: Selecting the non-ionic surfactant PEG-4000 as cloud point extraction, pesticides were extracted with isooctane by ultrasonic back extraction ...
KONG Ling-can   +4 more
core   +1 more source

Determination of Five Synthetic Colorants in Grain Food by High Performance Liquid Chromatography-tandem Mass Spectrum [PDF]

open access: yes, 2021
A new application of baking soda was developed, the synthetic colorant in cereal was extracted by adding with methanol solution in this paper.To develop new uses of edible bicarbonate,synthetic colorants were extracted from cereals by adding methanol ...
LIAO Ruo-yu   +4 more
core   +1 more source

Flow Injection on-line Preconcentration with Anion-exchange-resin and Flame Atomic Absorption Spectrometric Determination of Trace Cadmium(阴离子树脂微柱在线预富集火焰原子吸收法测定痕量镉)

open access: yesZhejiang Daxue xuebao. Lixue ban, 1999
建立了流动注射在线微柱预富集-火焰原子吸收(FAAS)法测定天然水中痕量镉的体系.在溶液pH7.2条件下,8-羟基喹啉-5-磺酸与Cd2+形成的络阴离子被填有阴离子树脂的微柱吸附而富集.用1mol/L硝酸溶液洗脱树脂上所吸附的镉.洗脱液在线输入FAAS测定.当采样速率为24次/时,富集倍数为10,检出限0.5μg/L,工作曲线线性范围0~100μg/L,RSD为1.0%(n=11,Cd2+浓度为100μg/L).本体系已用于天然水样中痕量镉测定,回收率90%~106%.
MaoXueqin(毛雪琴)   +4 more
doaj   +1 more source

Transcriptome Sequencing Analysis of Chrysomyia Megacephala Pupae in Different Growing Periods [PDF]

open access: yes, 2021
Objective To study the growth regulation, environmental adaption and epigenetic regulation of Chrysomyia Megacephala pupae, in order to obtain the transcriptome data of Chrysomyia Megacephala in different growing periods, and lay the foundation for ...
WANG Qi-yan, ZHANG Hong-ling, REN Zheng, et al.
core   +1 more source

武夷山甜槠群落的钾、钠累积和循环 [PDF]

open access: yes, 1998
是武夷山森林生态系统研究的一部分,主要讨论51年生甜槠[Castanopsiseyrei(Champ.exBenth.)Tutch.]群落的钾、钠元素的累积和循环.结果表明:甜槠群落的现存量中,含有的钾、钠总量分别为82.936g/m2和3.512g/m2,其中地上部分别为66.710g/m2(占总库存量的80.44%)和2.952g/m2(占84.05%);地下部分别为16.226g/m2(占19.56%)和0.560g/m2(占15.95%);各组分的库存量均是K>Na.该群落钾、钠的生物循环中,钾、
刘初钿   +5 more
core   +5 more sources

红壤小流域不同土地利用方式下土壤N,P流失特征研究

open access: yesShuitu Baochi Xuebao, 2005
研究了次降雨过程中红壤小流域5种不同土地利用方式土壤N,P养分流失特征。结果表明,在降雨后,花生地、花-橘间作、橘园、板栗园和水田5种利用方式表层土壤N,P养分含量均有不同程度下降,其中花生地N,P含量下降最为明显,水田N,P含量降幅则最小;不同形态养分平均降幅依次为有效氮(5.49%)、有效磷(5.25%)、全氮(1.45%)、全磷(0.59%)。各样地地表径流中水溶态N,P养分含量花生地明显高于其他样地,而泥沙中N,P养分含量则以水田最高;各样地侵蚀泥沙中N,P养分有明显的富集现象,板栗园和橘园N ...
王晓龙 李辉信 胡锋 秦江涛 张斌
doaj   +2 more sources

Accumulation and degradation of anionic surfactant linear alkylbenzene sulfonate (LAS) by Spirulina platensis(钝顶螺旋藻对阴离子表面活性剂(LAS)的富集与降解)

open access: yesZhejiang Daxue xuebao. Lixue ban, 2006
实验考察了使用钝顶螺旋藻富集与降解溶液中的阴离子表面活性剂(LAS).结果表明,溶液中不同浓度LAS存在下,钝顶螺旋藻的生长符合逻辑斯谛克方程;钝顶螺旋藻对LAS具有一定的富集能力,当LAS的质量浓度为0.5、1、2 mg/L时,24 h时富集量达到最大,分别为2. 43、4. 83、10.12 mg/g;钝顶螺旋藻对LAS也具有一定的降解能力,当LAS的质量浓度分别为0.
LIHao-xiang(李昊翔)   +3 more
doaj   +1 more source

甘油酯型n-3多不饱和脂肪酸富集方法研究进展Progress on enrichment methods of glyceride-type n-3 polyunsaturated fatty acids

open access: yesZhongguo youzhi, 2022
n-3多不饱和脂肪酸(n-3 PUFA)具有多种生理活性,其主要有3种存在形式,其中甘油酯型n-3 PUFA因其生物利用度高和不易被氧化而优于游离型和乙酯型。然而,目前鲜有对甘油酯型n-3 PUFA进行高纯度富集的方法。为了对甘油酯型n-3 PUFA的高值化更加深入的研究提供参考,综述了富集甘油酯型n-3 PUFA的3种常见方法(物理一步法、两步法和酶一步法)及优缺点。物理一步法可以避免产物氧化,但得率较低;两步法工艺复杂,并有可能产生环境污染;而酶一步法具有简单、高效等优点,成为学者们关注的焦点 ...
陈烨1,黄璟雯1,王熠璠1,黄家祺1,李康宁1,李才明1,王小三1,杨兆琪2 CHEN Ye1, HUANG Jingwen1, WANG Yifan1, HUANG Jiaqi1, LI Kangning1, LI Caiming1, WANG Xiaosan1, YANG Zhaoqi2
doaj   +1 more source

磁性共价有机骨架材料富集检测典型有机污染物的应用进展

open access: yesSe pu = Chinese journal of chromatography
痕量污染物因其在环境中的微量存在和基质的复杂性,难以直接通过仪器进行检测,对人类的健康构成潜在威胁。磁性固相萃取(MSPE)技术因具有操作简单、成本低廉、富集效率高等优势,在样品前处理领域一直备受关注。磁性固相萃取的研究聚焦于磁性材料的功能化,近年来研究者深入探索了磁性材料的功能化途径,将多种新兴材料引入磁性材料的修饰,有效拓展了磁性功能化材料的性能和应用领域。其中,磁性共价有机骨架材料(MCOFs)是一种具有代表性的材料,不仅具有比表面积大、稳定性高的特点,还兼具磁性材料的快速分离特性;可通过氢键作用、
Liu Jiang, Qingxiang Zhou
semanticscholar   +1 more source

一种基于疏水基团标记和反相色谱分离的富集策略及其在含赖氨酸多肽分析中的应用

open access: yesSe pu = Chinese journal of chromatography
赖氨酸(K)已被广泛用于靶向赖氨酸的交联剂设计、蛋白质复合物的结构解析以及蛋白质-蛋白质相互作用等研究领域。在基于液相色谱-串联质谱(LC-MS/MS)联用技术的“鸟枪法”蛋白质组学研究中,复杂生物样品中的蛋白质被酶切成上万条肽段,为直接分析含有K的肽段带来了巨大挑战。鉴于目前缺乏针对含K多肽的有效富集方法,本工作发展了一种基于疏水标记试剂C10-S-S-NHS和反相色谱分离的方法(简称HYTARP),实现对复杂样品中含K多肽的高效富集和鉴定。合成的C10-S-S ...
Yu He   +4 more
semanticscholar   +1 more source

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