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1.
研究了新荧光试剂7-(2,4-二羟基-5-羧基苯偶氮)-8-羟基喹啉-5-磺酸(DHCBAQS)与镁形成配合物的荧光性能,在pH90的硼砂缓冲介质中,试剂与镁形成1∶1配合物,其λex/λem=358nm/502nm。镁(Ⅱ)含量在0~480μg/L范围内呈良好线性关系,检测限为37μg/L,据此建立测定痕量镁的新方法,并应用于矿样及血清中痕量镁(Ⅱ)的测定,结果满意。  相似文献   

2.
镁,铝的激光—时间分辨荧光测定   总被引:2,自引:0,他引:2  
于水  刘智慧 《分析化学》1996,24(4):433-435
本文报道了用8-羟基喹啉-5-磺酸作荧光指示剂,采用激光-时间分辨技术进行镁、铝测定的新方法。在1-100μg/L的范围内,镁、铝的浓度和荧光强度呈良好的线性关系,方法的检出限分别为2μg/L和1μg/L。用标准牛肝粉对方法进行了验证,并用该方法对自来水进行直接测试。  相似文献   

3.
在4-二甲胺基吡啶的存在下,1,6-二氢-S-四嗪重排成3,6-二氢-S-四嗪,与双光气反应后再与不同的胺反应,合成了11种1,4-二取代产物,产物经元素分析、IR和^1H NMR确证。用UV和^1H NMR分析结果对反应机理进行了初步探讨。  相似文献   

4.
研究用8-羟基喹啉,氯仿萃取光度法测定试剂氯化钠和电解精盐水中微量镁,在酒石酸盐介质中,控制PH10.5-11.5,利用氯仿分层,能有效地排除氯化钠对测定的干扰,方法简便,快速,能增加取样量降低测定下限,可测定出试剂中0.00001%及电解精盐水中0.05ug/mlo^-1的镁含量。  相似文献   

5.
偶氮胂-DCS作为钙镁络合滴定指示剂的研究及其应用   总被引:1,自引:0,他引:1  
研究了利用光度显色剂偶氮胂-DCS作为钙镁联合滴定指示剂的可能性及使用该指示剂滴定钙镁的准确性,与常用的钙镁络合滴定指示剂进行了比较,并成功地应用于水泥试样中钙镁含量测定。结果表明,偶氮胂-DCS是一种良好的钙镁络合滴指示剂。  相似文献   

6.
以(+)-4,10-二氧杂三环[5.2.1.O^2,6]-癸-8-烯-3-醇为原料。经8步反应,对映选择性地合成出去氧维生素H的重要中间体:(2S,3S,4R)-2-正戊基-3,4-二叠氮基四氢噻吩。为对映选择性合成手性四氢噻吩类化合物提供了新的方法。  相似文献   

7.
研究了新荧光试剂7-(2,4-二羟基-5-羧基苯偶氮)-8-羟基喹啉-5-磺酸(DHCBAQS)与镁形成配合物的荧光性能,在pH9.0的硼砂缓冲介质中,试剂与镁形成1:1配合物,其λex/λcm=358nm/502nm。镁(Ⅱ)含量在0 ̄480μg/L范围内呈良好线性关系,检测限为3.7μg/L,据此建立测定痕量镁的新方法,并应用于矿样及血清中痕量镁(Ⅱ)的测定,结果满意。  相似文献   

8.
面包酵母用于苯乙酮的不对称还原研究   总被引:17,自引:1,他引:17  
刘湘  孙培冬  李明  许建和 《分子催化》2002,16(2):107-110
研究了面包酵母用于苯乙酮的不对称还原,分别考虑了反应温度,反应时间,底物浓度等因素对转化率和对映选择性的影响,结果表明,在合适的生物转化条件下,底物苯乙酮以中等的转化率被还原并得到较高对映体过量值的产物S-1-苯基乙醇。  相似文献   

9.
介绍了镁盐晶须填充材料在复合材料、塑料、金属铸造等行业的应用,对当前国内外镁盐晶须的合成研究发展现状进行了简要评述,结合作者对硼酸镁晶须的研究结果,指出了当前研究中存在的一些问题和不足。  相似文献   

10.
以新试剂2-(8’-羟基喹啉-5’-磺酸-7’-偶氮)-变色酸(简称8Q5SAC)作为显色剂,在硼砂-氢氧化钠缓冲体系中,用二阶导数吸光光度法测定微量镁,镁在0~15μg/25ml中符合比耳定律,可不经分离直接测定水样中镁,结果满意。  相似文献   

11.
A rapid, sensitive and selective high performance liquid chromatography (HPLC) method was developed and validated for determination of loganin in rat tissues. Samples were prepared based on a simple protein precipitation. Separation of loganin was achieved on a reversed-phase C(18) column (250 x 4.6 mm, 5 microm) with a mobile phase consisting of acetonitrile and water (16:84, v/v) at a flow rate of 1.0 mL/min. The detection wavelength was set at 236 nm and the temperature of the column was kept at 30 degrees C. The method was applied to study tissue distribution of loganin in rats after a single administration of loganin at a dose of 20 mg/kg. The highest level was observed in kidney, then in stomach, lung and small intestine. The lowest level was found in brain. The peak levels were attained at 90 min in most tissues. It was indicated that kidney was the major distribution tissue of loganin in rats, and that loganin had difficulty in crossing the blood-brain barrier. It was also found there was no long-term accumulation of loganin in rat tissues.  相似文献   

12.
头发微量元素及钙含量测定的应用价值评价   总被引:5,自引:1,他引:5  
以125例2~5岁儿童为对象,测定其全血和头发铅、锌、铁、钙含量;以全血铅、锌、铁、钙含量为标准,应用诊断试验评价方法评价头发铅、锌、铁、钙测定的应用价值。结果表明,头发铅测定的灵敏度可达88.3%,应用串联试验,头发铅测定的特异度可提高至81.8%,阳性预测值达69.6%,阴性预测值达78.8%。头发锌测定的灵敏度可达86.1%,特异度为52.4%,阳性预测值75.6%,阴性预测值为68.8%。头发铁测定的灵敏度为72.0%,特异度为77.5%,阳性预测值为83.6%,阴性预测值为63.3%,头发钙测定的灵敏度为78.9%,特异度为69.1%,阳性预测值为69.8%,阴性预测值为78.4%。锌缺乏、铁缺乏、钙缺乏,或铅负荷过高,或数种微量元素缺乏及铅中毒并存是当前严重影响儿童健康成长的常见原因。运用现代检测技术早期发现微量元素缺乏及铅中毒患儿并及时采取防治措施对促进儿童正常生长发育至关重要。头发样品容易采集、运送和保存,因此头发微量元素含量测定适合在中小城镇及农村使用。但其应用价值应进行科学评价。  相似文献   

13.
IntroductionHighperformancecapiliar}'electrophoresis(HPCE)isanewanalyticaltechnology'rapidly'developedinrecentyears.Withtheadvantagesofsmallsample.highsensitivity,highresolution.rapidanalysisandverycheaprunning,ithasbeenappliedinchemistry'.lifescienc...  相似文献   

14.
建立了亲水相互作用色谱柱(HILIC)串联C18柱的方法,高效分离实际样品中的胭脂红,并对色谱柱的串联顺序以及色谱分离条件进行优化。结果表明:当HILIC柱在前C18柱在后,流动相为乙腈-乙酸铵(5 mmol/L)=91∶9(V/V),流速为0.9 mL/min,柱温为25℃,检测波长为508 nm时,此时胭脂红的分离效果最佳。在最佳的色谱分离条件下,选用两种市售饮品进行实际样品的测定,回收率在81.2%~119%。方法适用于水相样品中的强极性物质的高效分离与分析。  相似文献   

15.
高效液相色谱梯度法测定雷公藤制剂中雷公藤甲素的含量   总被引:8,自引:0,他引:8  
胡永狮  张荣  汤秋华  吴平 《色谱》1999,17(3):265-267
采用高效液相色谱梯度法分离测定雷公藤制剂中雷公藤甲素的含量,用国产YWG色谱柱分离,二极管阵列检测器检测,所得三维光谱与空白光谱进行差减,取波长218nm处色谱图积分,定量。与等度法比较,梯度法具有更高的分离度、灵敏度,测定雷公藤口服液中雷公藤甲素的质量浓度为202.0μg/L,每片雷公藤片剂含甲素11.74μg,结果显著低于等度法和标示量(P<0.05)。  相似文献   

16.
建立柱后衍生–高效液相色谱法测定功能性饮料中牛磺酸的含量。功能性饮料中的牛磺酸经水溶提取后与邻苯二甲醛柱后衍生,以柠檬酸三钠溶液(p H 3.2)为流动相,用AMINO–NA色谱柱分离,荧光检测器检测,激发波长为338 nm,发射波长为425 nm,柱后衍生反应温度为55℃,流量为0.4 m L/min。牛磺酸质量浓度在5.0~25.0μg/m L范围内与色谱峰面积线性关系良好,r=0.999 8,检出限(S/N=3)为0.11μg/m L,测定结果的相对标准偏差为0.73%(n=6),加标回收率在99.2%~101.6%之间。该方法灵敏度高、选择性好,可用于市售功能性饮料中牛磺酸的测定。  相似文献   

17.
采用高频感应炉燃烧–红外吸收法测定银杏叶、银杏果肉、银杏壳和银杏仁中的硫含量。样品以艾士卡试剂为熔融剂,在800℃马弗炉内熔融1 h,冷却后测定硫含量。硫的质量分数在0.40%~4.00%范围内与吸收峰面积呈良好的线性关系,线性相关系数为0.990 4,检出限为0.000 9%。测定结果的相对标准偏差为4.04%(n=11),平均加标回收率为101.03%。将红外吸收法与电感耦合等离子体原子发射光谱法及硫酸钡重量法进行比对试验,3种方法测定结果相一致。利用该方法测定了不同区域银杏叶中硫的含量,结果表明,风景区和居民区银杏叶干燥基全硫的含量较低,重工业区硫含量较高。对同一地区的银杏果肉、银杏壳、银杏仁中干燥基全硫的含量进行比较,结果表明银杏果肉硫含量最高,银杏壳次之,银杏仁最低。该方法灵敏度高,重现性好,可用于银杏及银杏叶中硫含量的准确测定。  相似文献   

18.
提出了用气相色谱-质谱法测定纺织品中N-乙基全氟辛烷磺酰胺的方法。试样经甲醇超声提取后,在旋转蒸发仪中浓缩至5 mL,通过DB-5MS色谱柱分离,采用选择离子监测模式检测,定性离子为m/z69,108,131,169,448,定量离子为m/z108。N-乙基全氟辛烷磺酰胺的质量浓度在0.2~20.0 mg.L-1范围内与峰面积呈线性关系,检出限(3S/N)为0.69μg.L-1。用标准加入法做回收试验,测定平均回收率为97%。  相似文献   

19.
On-line coupled reversed phase liquid chromatography-capillary gas chromatography (RPLC-GC) was used in the separation of four derivatized beta-blockers and codeine in urine. Sample clean-up was accomplished in the LC part and compounds were separated in the GC part. After the LC column the aqueous phase was switched to organic solvent by on-line liquid-liquid extraction and the two phases were separated in a sandwich-type phase separator. The organic extract was then transferred to a loop-type LC-GC interface. Beta-blockers were derivatized on-line in the interface before GC analysis. Concurrent eluent evaporation was used during the introduction of the sample fraction, and excess of solvent vapors was removed via an early vapor exit. The sample pretreatment was minimal; the only manual pretreatment step was the filtration of the urine sample.  相似文献   

20.
An application of polyacrylamide-grafted-gum ghatti (PAAm-g-GGH) copolymer for transdermal delivery of an anti-psychotic drug, quetiapine fumerate triggered by electric stimulus was explored. The electro-responsive PAAm-g-GGH was prepared by free radical polymerization underneath nitrogen atmosphere subsequent to alkaline hydrolysis. The PAAm-g-GGH was used as drug reservoir gel and crosslinked films of GGH and PVA as rate controlling membranes (RCM). The reservoir gels were uniform and translucent; pH of gels was 6.56–7.06, which is in the pH range of skin and drug content was from 89.57% to 94.51%. The thickness of RCMs was 163–227?μ; thickness was increased with increased glutaraldehyde concentration and all the RCMs were permeable to water vapors. When electric stimulus was absent, a small amount of drug was permeated from the formulations, while drug conveyance was enhanced in the existence of stimulus. Drug permeation was increased with increase in electric stimulus from 2 to 8?mA. Over two fold increase in flux was observed after application of electric stimulus. Under “on–off” electric stimulus, faster drug permeation was seen under ‘on’ condition and permeation was decreased when stimulus was ‘off.’ Histopathology study confirmed reversible alteration of skin structure under electric stimulus.  相似文献   

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