彼阳新盖口服液中钙锌含量测定

本文研究了乳酸钙,葡萄糖酸锌含量测定,采用同位镀汞阳极溶出法在pH=5.8的HAc—NaAc缓冲溶液中,测定补锌制剂中锌的含量.线性范围0.02～0.08μg/ml,检出限为0.08μg/ml.以EDTA掩蔽Zn~(2+),间接KMnO_4法测定钙的含量。本文提出的方法是一种不经分离而能直接测定乳酸钙和葡萄糖酸锌的简便易行的方法.     

Meso—四—(4—甲基,3—磺基苯基)卟啉分光光度法测定葡萄糖酸锌含量

本文研究了在抗坏血酸存在下TTPS_4与Zn(Ⅱ)的显色反应。结果表明:在PH为4.40的NaAc—HAc缓冲体系中,以抗坏血酸和吐温—60为辅助配位剂,在沸水浴中加热8分钟,Zn(Ⅱ)与TTPS_4即形成稳定的高灵敏度配合物,最大吸收波长位于430 nm,ε_(430)=5.5×10~5。Zn(Ⅱ)浓度在0～0.120μg/ml范围内遵守比耳定律。应用此法直接测定补锌口服液葡萄糖酸锌含量,结果满意。     

4-(2-吡啶偶氮)-间二苯酚光度法测定奶粉中的锌含量

研究了显色剂4-(2-吡啶偶氮)-间二苯酚与锌的显色反应。在pH=9.0的硼砂-盐酸缓冲溶液中,非离子表面活性剂OP存在下,锌与4-(2-吡啶偶氮)-间二苯酚反应形成红色配合物,其最大吸收波长为500nm,表观摩尔吸光系数为6.24×104L·moL-1·cm-1。锌含量在0-60μg/50mL范围内符合比尔定律。该方法用于测定奶粉中的锌含量测定,加标回收率为97.8%-103.6%,相对标准偏差小于3.6%。     

4-(2-吡啶偶氮)-间二苯酚光度法测定奶粉中的锌含量

研究了显色剂4-(2-吡啶偶氮)-间二苯酚与锌的显色反应.在pH=9.0的硼砂-盐酸缓冲溶液中,非离子表面活性剂OP存在下.锌与4-(2-吡啶偶氮)-间二苯酚反应形成红色配合物,其最大吸收波长为500nm,表观摩尔吸光系数为6.24×104L·,moL-1·cm-1.锌含量在0～60μg/50mL范围内符合比尔定律.该方法用于测定奶粉中的锌含量测定,加标回收率为97.8%～103.6%,相对标准偏差小于3.6%.     

方波溶出伏安法测定镀镍液中的微量铜

为建立镀镍液中微量铜的测定方法,用方波溶出伏安法测定了镀镍液中的微量铜(Ⅱ).研究了最佳的测定条件,确立了测定方法.试验结果表明,在pH值为4.0～4.5的NH4Cl-Na2SO4底液中,Cu2 于-O.156 V(vsSCE)出现灵敏溶出峰,峰电流在铜(Ⅱ)浓度为5.0×10-7 ～1.0×10-5 mol/L时呈现良好的线性关系,回归方程Ip(μA)=1.06 1.08C(×10-6 mol/L),相关系数为0.999 4.方法的变异系数为2.7%,检出限为2.8×10-7 mol/L,回收率为94%～106%.该方法应用于现场镀镍液中微量Cu2 的测定,效果较好.     

用催化光度法测定电镀废水中的微量锌

在pH值为9.0的NH3·H2O-NH4Cl缓冲溶液中,痕量锌(Ⅱ)对过氧化氢氧化酸性大红的褪色反应具有强烈的催化作用,据此建立了一种测定痕量锌(Ⅱ)的催化光度新方法.方法的检出限为0.016μg/L,线性范围为0～160μg/L,用于测定电镀废水中微量锌,结果与5-Br-DMPAP光度法相符,6次测定值的相对标准偏差(RSD)<4%.     

GFAAS法测定高硅铝合金中微量锶的研究

以往对铝合金成分的分析主要针对主要元素 ,而对杂质元素分析未作特殊要求 ,对于高硅铝合金中微量锶的分析方法尚无报导 ,本实验研究了石墨炉原子吸收法测定高硅铝合金中含量范围为 0 0 0 5 %～ 0 10 %微量锶的可行性 ,对溶解酸的用量、基体铝的影响及共存元素的干扰分别进行反复试验 ,试验过程和结果如下。1　溶解酸用量影响试验　　高硅铝合金试样一般采用 (1+ 1)盐酸和 (1+1)硝酸溶解 ,再加入氢氟酸 ,试验表明 ,盐酸 (1+ 1)用量 10～ 30ｍＬ ,硝酸 (1+ 1)用量 2～ 6ｍＬ ,氢氟酸用量 2ｍＬ ,并将试样完全溶解 ,对测定无影响。加入 10ｍ…     

光谱修正-光吸收比差法测定镀铜废水中的微量Cu(Ⅱ)

光吸收比差法结合光谱修正技术,可以直接准确测定电镀废水中的微量铜(Ⅱ).在pH值为4.05的CH3 COOH-CH3 COONa缓冲溶液中,氯代磺酚S(CSPS)与Cu(Ⅱ)反应形成Cu-CSPS配位化合物,用光谱修正法表征其结构为[Cu2 (CSPS)2 (H2O)2]2-.利用此反应结合光吸收比差法建立了一种Cu(Ⅱ)定量分析新方法.结果表明:在适量NaF掩蔽剂存在的条件下,反应选择性良好;Cu(Ⅱ)含量为0～0.125 mg/L,Cu(Ⅱ)的检出限为1.35×10-3mg/L;该法用于测定镀铜废水中微量Cu(Ⅱ)时,结果与等离子体发射光谱(ICP-OES)法测得的结果相符,相对标准偏差小于4％,加标回收率为98.3％～ 105.0％.     

罗丹明B的荧光猝灭法测定钢铁中微量钨

本文研究了在酸介质中,NaCl存在的条件下,罗丹明B与钨酸根WO_4~_(2-)络合生成三元络合物使罗丹明B试剂荧光猝灭。以365 nm为最大激发波长,测定594 nm最大发射荧光强度。用钠型Dowex50W—X4离子交换树脂胶柱交换分离溶液中共存的磷酸根、重铬酸根、Cr~(3+)、Fe~(3+)等干扰离子,利用罗丹明B荧光强度减弱的程度和钨含量呈线性关系,测定钢样中微量钨。     

高效液相色谱法测定口服液中低聚木糖的含量

建立了测定口服液中低聚木糖含量高效液相色谱法。样品中的大分子多糖和较高聚合度木糖用乙醇水溶液沉淀除去,然后用4.0mol/L硫酸水解,高效液相色谱测定,外标法定量。方法线性范围为0.1~4.0mg/mL(r=0.999);回收率:酸解前为100.1~103.1%,相对标准偏差RSD为1.0%(n=6)。酸解后为89.8~95.2%,相对标准偏差RSD为2.2%(n=6);检测限为10mg/mL。该方法选择性好,结果准确可靠,适用于口服液中低聚木糖含量的测定。     

用Fe(Ⅲ)-磺基水扬酸-二溴苯基萤光酮-吐温-80三元络合体系分析锌中微量铁

用Fe(Ⅲ)-磺基水扬酸(SAL)-二溴苯基萤光酮(DBPF)形成兰色络合物,在pH=9～11的氨性介质和表面活性剂吐温-80存在下有色溶液可稳定32小时,该方法与常用铁-邻菲罗啉光度法相比具有发色迅速,再现性好,灵敏度高,Zn(Ⅱ)不干挠等优点。     

直接吸入火焰原子吸收分光光度法测定废水中锌含量的研究

本文研究了直接吸入火焰原子吸收分光光度法测定废水中的锌含量,最大吸收波长213.9 nm,锌含量在0.022 mg/L～1.250 mg/L内符合比耳定律,相关系数r=0.9991,利用该方法测定废水中的锌含量,变异系数小于5%,标准回收率98%～105%。     

Structural analysis of calcium phosphate coatings produced by pulsed laser deposition at different water-vapour pressures

Calcium phosphate coatings have been produced by pulsed laser deposition (PLD) at different water-vapour pressures. Rietveld refinement of X-ray diffraction (XRD) data allows us to determine that the structure of these coatings is apatitic with carbonate substitution for phosphate. The carbonate substitution decreases when the chamber pressure is raised, a fact that has been corroborated by Fourier transform–infrared (FT–IR) spectroscopy. Carbonate concentrations between 5 and 17 wt% have been calculated for the crystalline samples. Amorphous coatings are produced at the lowest and highest pressures due to the high carbonate concentration in the first case, and possibly to another type of substitution (Mg2+, HPO2-4, P2O4-7) or the inherent kinetics of the PLD process, in the second case.     

Triton X-100-5-Br-PADAP分光光度法选择性测定乳粉中微量铁

报道了以2-(5-溴-吡啶偶氮)-5-二乙氨基酚(5-Br-PADAP)为显色剂,应用分光光度法高选择性测定铁(Ⅲ)的新方法。实验结果表明,在pH4.0的乙醇介质中和Triton X—100、盐酸羟氨存在下,以746nm为测定波长,可选择性测定铁(Ⅲ)含量。本法线性范围为0～1.3μg/ml,表观摩尔吸收系数为2.94×10~4L·mol~(-1)·cm~(-1),批内和批间精密度cv%分别为1.2%、2.3%,平均回收率为98.9%。已用于乳粉中微量铁的直接测定,常见共存成分对测定无干扰。     

Quantitation of 4-(4-Chl0R0Phenyl)-2-Pyrr0Lidin0Ne in Baclofen Powder and Tablets

Abstract

A high-pressure liquid chromatography method to quantify 4-(4-chlorophenyl)-2-pyrrolidinone which is present as an impurity in baclofen powder and its dosage forms has been developed. The USP-NF method for the determination of 4-(4-chlorophenyl)-2-pyrrolidinone in powder is based on TLC and is only qualitative. The developed method was successfully used to quantify 4-(4-chlorophenyl)-2-pyrrolidinone in powder (USP-NF limit 1%) and in tablets (USP-NF limit 5%). The method is accurate and reproducible with a percent error of 4% for powder and 3% for tablets.     

Synthesis and Characterization of Bioceramic Calcium Phosphates by Rapid Combustion Synthesis

Calcium hydroxyapatite(Ca10(PO4)6(OH)2) has been synthesized in short duration by rapid solution combustion by employing different fuels.Calcium nitrate was taken as source of calcium and diammonium hydrogen phosphate served as the source of phosphate ions.Citric acid,tartaric acid,sucrose,glycine and urea were used as the fuels and nitrate ions and nitric acid were used as oxidizers.The influence of fuels on the morphology of the phase formed was studied.Results of the studies by powder X-ray diffraction a...     

Spectrophotometric determination of aluminium and indium with 2,2',3,4-tetrahydroxy-3',5'-disulphoazobenzene

2,2',3,4-Tetrahydroxy-3',5'-disulphoazobenzene (tetrahydroxyazon 2S) has been synthesized for the first time. This reagent has been used for the spectrophotometric determination of aluminium and indium ions. The method is very sensitive and selective for the direct determination of aluminium and indium. The optimum pH and absorbance of complexes formed of tetrahydroxyazon 2S with aluminium and indium are 5; 500 nm and 495 nm for Al and In, respectively. The system obeys Beer's law at 0.05-1.6 microg mL(-1) of aluminium and 0.06-2.1 microg mL(-1) of indium concentration. The molar absorptivity is 6.42 x 10(4)L mol(-1)cm(-1) for aluminium and 7.70 x 10(4)L mol(-1)cm(-1) for indium. The molar compositions of the complexes are 1:1 at optimum conditions. Alkaline and alkaline earth elements, halogens, thiourea, ascorbic acid, Cd(II), Pb(II), Mn(II), Zn(II), Co(II), Ni(II), Cr(III), Bi(III), La(III), Si(IV) do not interfere this method. The method can be applied to the direct spectrophotometric determination of trace amounts of aluminium in steel, alloys, waste water, river waters, spring water and ground water. The method was also successfully applied to the indium determination in artificial mixture.     

Spatially resolved detection of attomole quantities of organic molecules localized in picoliter vials using time-of-flight secondary ion mass spectrometry.

Time-of-flight secondary ion mass spectrometry (TOF-SIMS) has been utilized to detect femtomole and attomole quantities of organic species from within silicon nanovials. By using high-density arrays (10,000 nanovials/cm2) it is possible to chemically characterize diverse sample sets within a single chemical image. Molecular sensitivities, for the compounds investigated, very between 85 attomoles and 25 femtomoles, and typical acquisition times are approximately 100 ms per nanovial. These vials are fabricated using photolithography and KOH etching of Si[001] wafers to create wells, with a pyramidal cross section, ranging in size from 25 to 5625 micron 2. The volume ranges from 30 femtoliters to 100 picoliters, respectively. A drawn glass microinjector and solenoid-driven dispenser are utilized to array picoliter volumes of organic compounds into individual silicon nanovials. Solution concentrations typically range from 1 x 10(-2) to 1 x 10(-4) M allowing femtomole and even attomole quantities of material to be dispensed into each vial.     

Chemiluminescence determination of chlorinated volatile organic compounds by conversion on nanometer TiO2

A novel method based on conversion of chlorinated volatile organic compounds (CVOCs) to chlorine using a new type of column packed with nanometer TiO2 coupled with chemiluminescence (CL) has been developed for determination of them in workplace air. CVOCs are converted to chlorine by nanometer TiO2 at 220 degrees C. The Cl2 that is produced is selectively enriched on the column and subsequently released from the column at 600 degrees C. The Cl2 that is released is determined using a postcolumn CL detector. The CL intensity was linear with CCl4 in the range of 0.1-380 ppm, and the detection limit was 40 ppb (S/N = 3). Higher sensitivity could be acquired by using a larger volume of enrichment A similar procedure could be used for the determination of other CVOCs. CL intensities of CH2Cl2, CHCl3, and CCl4 at the same concentration increased in the order CH2Cl2 < CHCl3 < CCl4. The method has been successfully applied to the determination of CCl4 in workplace air, where 0.15-150 ppm CCl4 would be detected. The possible mechanism for the long lifetime of the column packed with nanometer TiO2 was tested using Raman spectrometer, X-ray powder diffraction, transmission electron microscopy and X-ray photoelectron spectroscopy. The results showed that the column packed with nanometer TiO2 could be operated in the reversible mode for determination of CVOCs under the present conditions. The method would be potentially applied to the analysis of other chlorinated compounds in environment, such as persistent organic pollutants.