共查询到19条相似文献,搜索用时 125 毫秒
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建立了凝胶渗透色谱(GPC)去脂,气相色谱-负化学电离源-质谱(GC-NCI-MS)法测定人血清中2,2’,4,4’,5,5’-六溴联苯(BB-153)、1,2-二(2,4,6-三溴苯氧基)乙烷(BTBPE)和德克隆(Dechlorane plus,DP,包括syn-DP和anti-DP)的方法。人血清样本加入内标13C12BB-153和13C10syn-DP,经蛋白质变性、脂肪提取、GPC去脂、酸性硅胶柱净化后,利用气相色谱-负化学电离源-质谱法测定样品中BB-153,BTBPE,syn-DP和anti-DP,监测离子分别为m/z 627.5,629.5,m/z 79,81以及m/z 652,654。结果表明,13 C12 BB-153和13 C10syn-DP的血清加标回收率分别为91.5%±8.9%和92.3%±8.1%,检出限为0.6~1.2 ng/g脂肪。应用本方法对人血样品进行测定,BB-153和BTBPE在所有样本中均未检出,syn-DP和anti-DP的浓度范围分别是0.7~9.2 ng/g脂肪和0.6~2.0 ng/g脂肪。 相似文献
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建立了固相萃取-气相色谱-负化学源质谱联用法(SPE-GC-NCI/MS)同时测定海水中5种得克隆类物质的方法。采用二氯甲烷进行液液萃取(LLE),萃取液经过硅胶固相萃取小柱净化后,在15 m长的DB-5HT高温毛细管气相色谱柱上分离,NCI/MS以选择离子监测模式检测目标化合物。方法中5种得克隆类物质Dec 602,Dec 603,Syn DP和Anti DP的检出限分别为0.01,0.01,0.08,0.02和0.01 ng/L,平均加标回收率分别为61%,75%,75%,87%和91%,RSD均小于5.1%。采用该法对河北近岸海域16个采样站位海水样品进行分析,所有采样站位均有得克隆类物质检出。 相似文献
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采用气相色谱/负离子化学电离质谱法测定土壤中的硫丹及其代谢物.外标法定量,α-硫丹、β-硫丹及硫丹硫酸酯在0.200~10.0μg/L范围内线性良好,方法检出限分别为0.02、0.02及0.03μg/kg,空白加标平行测定的RSD为3.6%~4.3%,土壤样品加标回收率为83.6%~86.4%.本方法定性定量准确,适用于土壤中硫丹的测定. 相似文献
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气相色谱-负离子化学源/质谱法(GC-NCI/MS)分析鱼类和贝类样品中多溴联苯醚和多溴联苯 总被引:1,自引:0,他引:1
将气相色谱-负离子化学源/质谱法(GC-NCI/MS)应用于分析鱼类和贝类样品中5种多溴联苯醚(PBDEs)和5种多溴联苯(PBBs)残留.鱼类和贝类样品以正己烷/丙酮(1∶1,V/V)作为提取剂,采用超声萃取法,提取液经酸性硅胶和中性硅胶层析柱净化和正己烷洗脱后,以PCB-103为内标物和GC-NCI-MS的选择离子... 相似文献
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气相色谱-负离子化学电离质谱法测定水产品中残留的硫丹及其代谢物 总被引:1,自引:0,他引:1
建立了水产品中α-硫丹、β-硫丹及硫丹硫酸酯残留量的分析方法。样品经丙酮-正己烷混合溶剂提取、转溶至乙腈中、冷冻去除油脂、活性炭和中性氧化铝固相萃取小柱(SPE)串联净化处理后,以选择离子方式进行气相色谱-负离子化学电离质谱分析,采用外标法定量。硫丹和硫丹硫酸酯的选择离子分别为m/z 406,408,404,372和m/z 386,388,384,422。每种化合物的最低定量检测限为0.5 μg/kg,回收率为83%~105%,相对标准偏差低于13%。该方法简单、快速、准确,能满足水产品中硫丹残留的检测需要。 相似文献
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提出了气相色谱四极杆质谱法测定鳗鱼中硫丹和毒死蜱农药残留量的方法.样品以乙酸乙酯为提取剂,经浓缩、净化、氮气吹干后用正己烷溶解,采用气相色谱-质谱负化学电离源方式进行选择离子扫描测定.各标准曲线线性范围为0.2~10.0μg·kg-1,回收率为81%~95%;测定结果的相对标准偏差(n=8)小于5%,检出限(3S/N)为0.5μg·kg-1. 相似文献
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Chao Jia Liheng Chen Ziqiang Shao Umesh P. Agarwal Liangbing Hu J. Y. Zhu 《Cellulose (London, England)》2017,24(6):2483-2498
We fabricated cellulose nanocrystals (CNCs) and cellulose nanofibrils (CNFs) from different cellulose materials (bleached eucalyptus pulp (BEP), spruce dissolving pulp (SDP) and cotton based qualitative filter paper (QFP) using concentrated oxalic acid hydrolysis and subsequent mechanical fibrillation (for CNFs). The process was green as acid can be easily recovered, and the prepared cellulose nanomaterials were carboxylated and thermally stable. In detail, the CNC yield from the different materials was similar. After hydrolysis, the DP of the cellulose materials decreased substantially, whereas the mechanical fibrillation of the cellulosic solid residues (CSRs) did not dramatically reduce the DP of cellulose. CNCs with different aspect ratios were produced from different starting materials by oxalic acid hydrolysis. The CNCs and CNFs obtained from BEP and QFP possessed more uniform dimensions than those from SDP. On the other hand, CNFs derived from SDP presented the best suspension stability. FTIR analyses verified esterification of cellulose by oxalic acid hydrolysis. The results from both XRD and Raman spectroscopy indicated that whereas XRD crystallinity of CNCs from BEP and QFP did not change significantly, there was some change in Raman crystallinity of these samples. Raman spectra of SDP CNCs indicated that the acid hydrolysis preferably removed cellulose I portion of the samples and therefore the CNCs became cellulose II enriched. TGA revealed that the CNCs obtained from QFP exhibited higher thermal stability compared to those from BEP and SDP, and all the CNCs possessed better thermal stability than that of CNCs from sulfuric acid hydrolysis. The excellent properties of prepared cellulose nanomaterials will be conducive to their application in different fields. 相似文献
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Zhixiong Shi Yifei Wang Piye Niu Jiandi Wang Zhiwei Sun Shuhua Zhang Yongning Wu 《Journal of separation science》2013,36(20):3402-3410
A method has been developed and validated for the concurrent extraction, clean‐up, and analysis of polybrominated diphenyl ethers (PBDEs), α‐, β‐, and γ‐hexabromocyclododecane (HBCD), and tetrabromobisphenol A (TBBPA) in human milk and serum. Milk and serum samples were extracted using accelerated solvent extraction with acetone/hexane 1:1, v/v and liquid–liquid extraction with methyl‐tert‐butyl ether/hexane 1:1, v/v, respectively. The removal of co‐extracted biogenic materials was achieved by gel permeation chromatography followed by sulfuric acid treatment. The fractionation of the PBDEs and HBCD/TBBPA was performed using a Supelco LC‐Si SPE cartridge. The detection of the PBDEs was then performed by GC–MS and that of the HBCDs and the TBBPA was performed using UPLC–MS/MS. The pretreatment procedure was optimized, and the characteristic ions and fragmentation of the analytes were studied by MS or MS/MS. A recovery test was performed using a matrix spiking test at concentrations of 0.05–10 ng/g. The recoveries ranged from 78.6–108.8% with RSDs equal to or lower than 14.04%. The LODs were 1.8–60 pg/g. The usefulness of the developed method was tested by the analysis of real human samples, and several brominated flame retardants in different samples were detected and analyzed. 相似文献
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O. N. Kononova A. I. Zemlyanskaya E. V. Duba 《Russian Journal of Applied Chemistry》2015,88(11):1763-1769
Sorption recovery of nickel(II) and cobalt(II) in their joint presence in sulfuric acid solutions was studied on new samples of domestic ion exchangers of CYBBER brand. It was shown that the ion exchangers under study have a high sorption capacity for ions of both nonferrous metals, depending on the structure of a sorbent and on the acidity of a contacting solution. It was found that, after Co(II) and Ni(II) ions are extracted from weak or strong sulfuric acid solutions, they can be effectively eluted from the ion exchangers under study with a 2 M hydrochloric acid solution to an extent of 85–95% (nickel) and 87–95% (cobalt). 相似文献
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L. Doretti D. Ferrara G. Barison 《Journal of Radioanalytical and Nuclear Chemistry》1990,141(1):203-208
A procedure for the determination of the three main isotopes of thorium in gas lantern mantles by alpha-spectrometry has been developed. The samples examined were dissolved in concentrated nitric acid and thorium was precipitated as hydroxide. Thorium was then dissolved in hydrochloric acid to be extracted into a TOPO solution, back-extracted with sulfuric acid, electrodeposited onto a steel disc and finally counted alpha-spectrometrically. The radiochemical recovery for thorium was 94% with a counting efficiency of 37%. 相似文献
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Neymara C. Nepomuceno Amelia S. F. Santos Juliano E. Oliveira Gregory M. Glenn Eliton S. Medeiros 《Cellulose (London, England)》2017,24(1):119-129
Cellulose nanowhiskers were extracted from the spines of Mandacaru (Cereus jamacaru DC.), a cactus native to the Caatinga biome of northeastern Brazil, using sulfuric acid hydrolysis preceded by alkaline treatment and bleaching. Results showed that three bleaching steps were required to remove most of the non-cellulosic constituents of the spines that yielded 77.4% cellulose. Nanowhiskers size decreased from about 400 to 260 nm when extraction time varied from 60 to 120 min, this was also evidenced by X-ray diffraction. Alkaline treated and bleached samples had lower thermal stability as compared to untreated spines due to removal of lignin and increased surface area. The amount of time samples were treated with sulfuric acid influenced the thermal stability and consequently the degree of crystallinity of the nanowhiskers. Cellulose nanowhiskers were obtained from Mandacaru spines providing a new renewable source of reinforcement with potential applications in nanocomposites. 相似文献
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U. S. Gill H. M. Schwartz B. Wheatley 《International journal of environmental analytical chemistry》2013,93(2-4):153-161
Abstract A method for the determination of toxaphene in whole blood using gas chromatography (GC)-electron capture negative ion ECNI/MS and pure polychlorobornane congerners has been evaluated. Blood samples were extracted with hexane/acetone (9:1), extracts defatted with sulfuric acid, analytes fractionated on Carbopack-C/ Florisil (or silica gel) SPE columns then concentrated to final volumes for GC-ECNI/MS analysis. For confirmation, interference from PCBs and other organochlorine pesticides were removed by nitration. 相似文献
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采用气相色谱–质谱联用法检测棉花中3种苯氧羧酸类除草剂[2,4-D,2,4,5-T,2-甲-4-氯丁酸(MCPB)]的残留量。样品用甲酸酸化的丙酮提取,硫酸催化甲酯化反应,用气相色谱–质谱联用仪测定。采用HPLC法与GC–MS法对提取与衍生化步骤进行优化。2,4-D,2,4,5-T,MCPB 3种化合物在0.075~7.5 mg/kg范围内线性均良好,检出限分别为0.5,0.5,0.8μg/kg,测定结果的相对标准偏差分别为4.1%,4.3%,4.0%(n=5),方法回收率分别为93.6%,95.5%,93.9%。该方法各项指标均可满足检测要求。 相似文献
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A sensitive and reliable HPLC method that allows simultaneous quantification of phytoestrogens extracted from kudzu-root and soy preparations, and serum samples has been developed. Kudzu-root and soy preparations were mixed with 5 microg flavone and 15 microg rutin (internal standards) and the phytoestrogens were extracted by using solid-phase (C18) extraction cartridges. Blank or spiked serum samples were extracted by using either C18 cartridges or trichloroacetic acid-methanol extraction. The extracts were analyzed by the HPLC equipped with a reverse-phase (250 x 4 mm, C18) column and UV, diode-array or MS detector. A linear gradient of acetic acid and acetonitrile provided excellent separation of glycoside and aglycone-phytoestrogens from kudzu root and soy preparations. The C18 cartridge extraction of serum yielded excellent recovery of both glycoside- and aglycone-phytoestrogens, while the trichloroacetic acid-methanol extraction yielded excellent recovery of glycoside but poor recovery of aglycone compounds. UV and MS detectors were suitable for phytoestrogen analysis in plant and serum samples, while the diode-array detector was suitable for generating the UV absorbance curve for phytoestrogens. 相似文献