首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 203 毫秒
1.
检测痕量纳米金的纳米催化光度法   总被引:2,自引:0,他引:2  
在EDTA—NaOH介质中,金纳米微粒对盐酸联氨还原硫酸铜生成铜微粒这一慢反应具有较强的催化作用.铜微粒在750nm处产生一个吸收峰.随着纳米金浓度的增大,750nm处的吸光强度线性增大.对于粒径为10、30、50nm的纳米金,其线性范围、回归方程、检出限分别为0.12~1.68、0.36~2.80、1.00~5.00nmol/L,△A750nm=0.3205CAu+0.0076、△A750nm=0.2201CAu+0.0056、△A750nm=0.1150CAu+0.0066,0.05、0.20、0.50nmol/L Au.分别对0.50、1.00nmol/L纳米金(d=10nm)平行测定10次,求得其相对标准偏差分别为4.2%、3.5%.  相似文献   

2.
建立了以香烟过滤嘴纤维作吸附剂,在线固相萃取-高效液相色谱(SPE—HPLC)测定水中邻硝基苯甲酸、对硝基苯胺、邻硝基苯酚、3-氯硝基苯四种硝基类化合物的方法。邻硝基苯甲酸、对硝基苯胺、邻硝基苯酚、3-氯硝基苯分别在0.006~4.80、0.003~2.40、0.002~1.60、0.002~1.60mg/L范围内峰面积与浓度呈线性关系,相关系数分别为0.9994、0.9996、0.9997和0.9996;检出限(S/N=3)分别为1.0、0.8、0.6,0.6μg/L;富集倍数分别为28.2、176.6、172.1、153.3。该法用于河水中四种硝基类化合物的测定,回收率为85.41%~116.44%,相对标准偏差在1.1%~5.4%范围内。  相似文献   

3.
考察了微蒸馏气相色谱法测定水样中多种低级脂肪醇的可行性。利用微蒸馏技术将水中的醇分离富集,用程序升温气相色谱法测定。正丙醇、异丙醇、正丁醇、异丁醇、正戊醇、异戊醇的浓缩倍数分别为169.3,137.6,197.4,149.2,142.7,126.0。检出限分别为0.021,0.031,0.032,0.032,0.066,0.065mg/L。样品中所存在组分的平均回收率分别为甲醇82.60%,正丙醇93.25%,正丁醇94.88%;相对标准偏差分别为甲醇7.7%,正丙醇4.7%,正丁醇3.4%。方法适用于水中多种微量低级醇的同时分析。  相似文献   

4.
富硅微量元素肥料的应用研究   总被引:1,自引:1,他引:0  
使用自制的富硅微量元素肥料对水稻、甘蔗、花生进行实验。结果表明水稻、甘蔗、花生增产达到显著水平以上的分别占83.33%、83.33%和58.33%,三种作物的最佳N、SiO2施用比例分别为1:0.84、1:0.65和1:0.65~0.85。该肥可使水稻增产稻谷5.57%~12%,最高增产达21.17%;花生增产6.02%~14.84%,最高增产28.91%;甘蔗增产可达10.51%~11.73%,  相似文献   

5.
氢化物-原子荧光光谱法连续测定锌精矿中砷、锑、铋、锡   总被引:14,自引:2,他引:14  
李岩 《分析化学》2004,32(2):205-208
用氢化物-原子荧光光谱法,一次性分解样品,在L-半胱氨酸存在下,实现了锌精矿中As、Sb、Bi、Sn的连续测定。其回收率分别为92.8%~105.0%、96.0%~109.3%、96.0%~111.6%和96.7%~103.7%;检出限分别为0.35、0.31、0.19和0.35μg/L。用该方法分析锌精矿样品,结果满意。  相似文献   

6.
上海精谱仪器有限公司是上海市高科技产业区的高科技企业.专业从事工业生产过程控制中快速能谱分析仪器的研究和制造.是中国X荧光分析仪的科研生产基地。公司拥有一支强大的X荧光分析仪研制技术人员组成的专家队伍.他们多年从事核物理,电子学.X荧光软件.机械,自动控制、分析应用等学科的研究.密切关注并不断地引进国际分析领域的新技术、新器件.新方法.使精谱产品处于国际领先水平。让国内分析行业享用到国际上成熟的仪器.先进的分析方法和人性化的软件。精谱始终引领着中国能量色散X荧光分析仪向国际先进水平方向发展。产品广泛应用于钢铁、冶金.有色金属.水泥.煤炭.玻璃.贵金属.石油、化工.耐火材料、机械工业.食品.医药等行业。  相似文献   

7.
戈早川  周建明 《分析化学》2004,32(1):99-101
以2%CPC-醋酸乙酯(9:1)胶束溶液为展开剂,在聚酰胺薄膜上成功地分离了小檗碱、巴马汀和药根碱。以345nm为测定波长,550nm为参比波长进行扫描测定,建立了一种新的同时测定黄连及其制剂中小檗碱、巴马汀和药根碱的胶束薄层扫描法。小檗碱、巴马汀和药根碱的线性范围分别为0.2—2.4、0.1—1.0和0.1—1.0μg;回收率分别为97.7%-99.4%、101.7%~102.6%和96.7%-97.8%;相对标准偏差分别为1.4%-1.7%、1.9%-2.7%和1.8%-2.2%。  相似文献   

8.
用稀土氧化物Ln2O3(Ln: La, Nd, Eu, Ho, Yb, Sm )对戊二酸锌进行改性, 制备出新催化剂. 在80 ℃、3.0~3.5 MPa 条件下, 该催化剂催化二氧化碳与环氧丙烷共聚, 反应时间为6.5~7.0 h, 催化活性达到3.0~3.4 g polym ./(g cat.·h), 转化率70.8% ~79.7% , 共聚物中碳酸酯单元分数48.4% , 产品热分解温度238.1 ℃.  相似文献   

9.
火焰原子吸收光谱法测定尘铅前处理方法的研究   总被引:1,自引:0,他引:1  
采用火焰原子吸收光谱法测定尘铅样品,在0-1.00mg/L范围内样品中铅含量与吸光度呈良好线性关系,检出限为2.88μg/m^2(按定容体积50mL、采样体积400L计)。采取酸煮法、索氏提取法、微波消解法、超声波提取法等4种前处理方法,在0.100,0.500,1.00mg3个质量水平对空白滤筒进行加标回收试验,4种前处理方法的回收率和测定结果的相对标准偏差分别为91.8%-97.4%,2.2%~3.2%;83.0%-86.8%,7.4%-10.3%;93.6%-97.2%,2.5%~3.7%;89.3%-90.9%,3.2%~4.5%,提取效果以酸煮法和微波消解法最佳,超声波提取法次之,索氏提取法最差。  相似文献   

10.
利用化学发光方法研究了Ar(3P0,2)与SO2,SOCl2在单次碰撞条件下SO(A)的形成动力学,通过对实验光谱进行曲线拟会,得到了SO(A,υ')的初生态布居.分别是N0:N1:N2:N3:N4:N5:N6=1.00:0.67:0.57:0.55:0.50:0.35:0.30和1.00:0.69:0.61:0.53:0.40:0.34:0.26.利用参考反应法求算了SO(A)的形成速率,分别为:4.55×10-12cm3•molecule-1•s-1和2.87×10-12cm3•molecule-1•s-1,与总猝灭速率相比较,发现解离激发为反应的次要出口通道.通过惊奇度分析,对激发解离机理进行了讨论.  相似文献   

11.
农药异丙威与小牛胸腺DNA的作用研究   总被引:2,自引:0,他引:2  
在生理酸度条件下,采用紫外光谱和荧光光谱法研究异丙威与小牛胸腺DNA的作用表明:DNA对异丙威的荧光有明显的猝灭作用,属于静态猝灭方式;K4[Fe(CN)6]猝灭试验发现DNA对异丙威有明显的保护作用,离子强度的改变对异丙威和异丙威-DNA体系的荧光均无明显影响;异丙威的加入使DNA的熔点升高,并且异丙威能够竞争置换EB与DNA的结合位点。上述实验也表明,异丙威以嵌插方式作用于DNA的结合位点,有可能通过形成DNA加合物的形式造成DNA损伤,从而最终导致基因突变。  相似文献   

12.
杨容  傅承光 《色谱》1994,12(6):431-432
研究了基质固相分散(MSPD)处理复杂样品技术与高效液相色谱法相结合测定食物中痕量异丙威和溴氰菊酯残留物的新方法。研究了MSPD技术进行前处理的实验条件并讨论了与传统残留分析的区别。首次将MSPD技术应用于水果、粮食等食物中异丙威和溴氰菊酯残留物的高效液相色谱分析,并对定量检测条件作了详细的研究。  相似文献   

13.
In this study, a carboxyl group was introduced into the isoprocarb molecule to obtain an isoprocarb hapten, which was then coupled with a protein to obtain an artificial antigen. Three monoclonal antibody cell lines, 1D11, 6E6 and 1B5, were finally obtained by mouse immunization, cell fusion and subcloning, and the antibody produced by cell line 1B5 had the best affinity and sensitivity. The monoclonal antibody was highly sensitive and specific for isoprocarb, with an IC50 of 2.09 ng/ml and a cross‐reactivity rate of <0.21%. By optimizing the indirect competitive (ic)‐ELISA, the optimal conditions were determined to be pH 7.4, 0% methanol and 0.8% NaCl, the limit of detection value was 0.23 ng/ml, and the linear range of the ic‐ELISA was 0.46–9.62 ng/ml. The recovery rate of the isoprocarb cucumber sample was 97–99% for the ic‐ELISA method. In addition, we successfully developed an immunochromatographic test strip for the detection of isoprocarb residues. The cutoff values in phosphate‐buffered saline and cucumber extract were 10 and 25 ng/ml, respectively. Both methods met the requirements for isoprocarb residue detection in agricultural products, and can be used for semiquantitative and qualitative analysis of isoprocarb in vegetables.  相似文献   

14.
We developed an analytical method for the detection and quantitation of five pesticides and some of their metabolites - 3-hydroxycarbofuran, 3-ketocarbofuran, carbofuran, carbosulfan, and isoprocarb - using micellar electrokinetic chromatography coupled with a UV-Vis detector. The optimum separation conditions were 20 mM phosphate buffer (pH 8.0) containing 15 mM sodium dodecyl sulfate. The detection wavelength was set at 200 nm and the applied voltage was 12.5 kV. Under these conditions, baseline separation of five pesticides was achieved in 15 min, and the detection limits (S/N = 3) of 3-hydroxycarbofuran, 3-ketocarbofuran, carbofuran, carbosulfan, and isoprocarb were 0.3, 0.3, 0.3, 4.0, and 0.3 μM, respectively. The linear ranges for 3-hydroxycarbofuran, 3-ketocarbofuran, carbofuran, and isoprocarb were between 1.0 and 50.0 μM and that for carbosulfan was between 10.0 and 100.0 μM, with R(2) larger than 0.995. When applied to the analysis of a carbofuran-spiked rice sample, this approach yielded results with excellent repeatability (3.3%, n = 5), reproducibility (4.5%, n = 5), separation efficiency (>2.1 × 10(4) theoretical plates), and recovery (95.5 ± 1.4%, n = 5).  相似文献   

15.
表面解吸化学电离质谱法快速检测蔬菜中痕量氨基甲酸酯   总被引:1,自引:0,他引:1  
采用自行研制的表面解吸常压化学电离源(SDAPCI),首次在无需样品预处理的前提下用质谱法直接测定了多种蔬菜表面残留的痕量氨基甲酸酯,并用串联质谱对所获得的不同氨基甲酸酯农药的离子进行了结构鉴定,排除了检测结果的假阳性。该方法对待测样品无污染,方法检测限低于10-14g/cm2,单个样品的测定时间平均少于1 s,特别适合于对批量样品进行快速检测。  相似文献   

16.
The ion exchange method was used to intercalate a poor water-soluble insecticide, isoprocarb into zinc layered hydroxide (ZLH). PXRD analysis indicated the successful intercalation with good crystallinity for the resulting nanocomposite, with a basal spacing of 33.1 Å. FTIR analyses showing the resemblance of an absorption peak of the nanocomposite with the host and the guest anion. The thermal analysis confirmed that the nanocomposite had better thermal stability compared to the pristine isoprocarb. The nanocomposite also characterized by elemental and surface morphology analysis. The surface analyses of the host and nanocomposite showed mesoporous-type material characteristics. On the whole, the intercalation process decreased the pore size of the nanocomposite compared to the pristine host, layered zinc layered hydroxide-sodium dodecyl sulphate (ZLH-SDS). The obtained material is believed has a great potential as an environmentally friendly insecticide.  相似文献   

17.
The pyrolysis behavior of isoprocarb (an insecticide with contact and stomach action) is investigated using pyrolysis-gas chromatography-mass spectrometry. The pyrolysis products are separated using an HP-5 column under temperature program with helium as the carrier gas. The total of 80 separated pyrolysis components at 600 degrees C, 750 degrees C, and 900 degrees C under helium atmosphere are identified using a probability-based matching search procedure, combined with the correlation of boiling point (BP) and Lee retention index (RI). Some of the BP values of the tentative components are estimated using the group contributions method because experimental values are not available. The levels of the identified components are estimated by the peak area normalization method from the chromatogram. It is found that isoprocarb decomposes more with the increase of temperature, and a large number of mono aromatics and polycyclic aromatic hydrocarbons and their derivatives are produced when the pyrolysis temperature is higher than 750 degrees C. The content of the decomposition products in the pyrolysate varies from 0.04% to 22.20%.  相似文献   

18.
杨秀敏  王志  王春  韩丹丹  陈永艳  宋双居 《色谱》2007,25(3):362-366
应用中空纤维液相微萃取(HP-LPME)技术建立了水样中呋喃丹、西维因、异丙威和乙霉威的高效液相色谱分析方法。对影响HP-LPME的实验条件进行了优化。采用Accurel Q3/2聚丙烯中空纤维,以甲苯为萃取溶剂,于室温、搅拌速度为720 r/min条件下在4.5 mL样品溶液中萃取20 min,萃取物在室温下经氮气流吹干后用流动相溶解进样。采用Baseline C18分离柱(4.6 mm×250 mm,5.0 μm),以甲醇-水(体积比为60∶40) 为流动相,流速为1.0 mL/min。呋喃丹、西维因、异丙威和乙霉威的检测波长分别为200,223,200和208 nm。该方法对4种氨基甲酸酯类农药的富集倍数均大于45倍;4种氨基甲酸酯类农药在10~100 μg/L质量浓度范围内,其质量浓度与峰面积之间有良好的线性关系,相关系数均大于0.99;呋喃丹、西维因、异丙威和乙霉威的检出限(S/N=3)分别为5,1,5和3 μg/L;实际水样中的加标回收率为82.0%~102.2%,相对标准偏差为2.0%~6.2%(n=6)。  相似文献   

19.
The influence of salt additive on cloud point extraction (CPE) of isoprocarb and promecarb insecticides is described. Types of salt (Na(2)CO(3), CaCl(2), MgSO(4), Na(2)SO(4), NaHCO(3) and NaCl) and concentrations were studied. The extracted target compounds were analyzed using reversed phase high-performance liquid chromatography. Among the salts studied, Na(2)CO(3) was found to be the most effective salt for salting out of both insecticides, resulting in high extraction efficiency (>95%) and high enrichment factor of up to 18 compared to extraction without preconcentration. The optimum CPE conditions were 1.5% (w/v) Triton X-114, 3.0% (w/v) Na(2)CO(3), and 20-min equilibration at 45°C. Under the selected conditions, the linear range of 0.05 to 3.0 mg/L was found for both analytes. The limits of detection for isoprocarb and promecarb were 10 and 20 μg/L, respectively. High intra-day (n = 9) and inter-day (n = 3 × 4 days) precisions with relative standard deviations <1% and <8% were obtained for retention time and peak area, respectively. The proposed method was successfully applied for the residue analysis of target compounds in beverages (i.e., fruit juice, vegetable juice and wine samples), which provided high recoveries (>80%, on average) for spiked samples at three levels (0.05, 0.10 and 0.50 mg/L).  相似文献   

20.
A simple and sensitive method was developed for the determination of three carbamate pesticides in water samples. It is based on temperature controlled ionic liquid dispersive liquid phase microextraction combined with high-performance liquid chromatography. The ionic liquid 1-hexyl-3-methylimidazolium hexafluorophosphate was used as the extractant, and the factors affecting the extraction were investigated in detail. The detection limits obtained for isoprocarb, diethofencarb and fenothiocarb are 0.91, 0.45, and 1.40 μgL-1, respectively, and the precisions are in the range between 1.0 and 1.8% (n?=?6). The method was validated with environmental water samples and the results indicate that it represents a viable alternative to existing methods.
Figure
Temperature controlled ionic liquid dispersive liquid phase microextraction was developed for the enriching three carbamate pesticides. 1-Hexyl-3-methylimidazolium hexafluorophosphate was used as the extractant. The detection limits for isoprocarb, diethofencarb, fenothiocarb are 0.91, 0.45, 1.40 μgL-1. Real-world environmental water samples analysis indicated that it was a viable alternative to existing methods.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号