铋膜电极差分脉冲溶出伏安法测定镉

用铋膜电极对水样中的Cd2+进行了差分脉冲溶出伏安法检测.观察并优化了采用同位镀铋法测定水样中的镉离子时的影响条件.结果显示:镉可以在铋膜电极上得到灵敏的电位溶出峰.加入1/15mol/L的NazHPO4-KH2PO4缓冲液(pH7.5),在1.1V电压下富集300s,镉的检测下限达到0.1μg/L,在1-120μg/L内呈现良好的线性关系.每次使用完可方便的将电极上残留的镉和铋溶出,从而使得各次检测具有良好的重现性.     

阻抑过氧化氢氧化橙黄G褪色分光光度法测定人发中的微量铋

基于在pH=11.00的NH3-NH4Cl缓冲溶液中,铋(Ⅲ)对H2O2氧化橙黄G的褪色反应具有阻抑作用,据此建立了阻抑动力学分光光度法测定微量铋(Ⅲ)的新方法.方法的线性范围为0.008-0.32μg/mL,检出限为1.15×10-3μg/mL,对4.00μg/25mL铋(Ⅲ)进行11次平行测定A阻值的相对标准偏差为2.2％.本方法用于人发中微量铋的测定,回收率为99.3％-102.7％.     

铋膜电极电位溶出法测定水果罐头中的痕量Sn2+

研究了同位镀铋膜法制备铋膜电极测定痕量Sn2+的电位溶出法。在0.1mol/L HAc-NaAc缓冲溶液(pH 4.8)中,通过开路富集于-1.2V进行电沉积,Sn2+与Bi3+被还原为单质富集于电极表面,在铋膜电极的电催化作用下再进行电位溶出,于-0.61V左右单质锡被氧化为Sn2+获得一灵敏的氧化溶出峰,其浓度与峰值成线性关系,线性范围为0.1—5.0mg/L,该方法的最低检出限为0.03mg/L(3σ)。利用该电极测定了水果罐头中痕量Sn2+的含量,并与国标方法作对比实验,结果表明该方法可用于实际样品分析。     

CPB-PVA-PV-铋显色体系的研究与应用

本文研究了在弱酸性溶液中 ,CPB- PVA- PV-铋体系的显色反应 ,其络合物的最大吸收波长为5 4 2 nm,络合物的表观摩尔吸光系数为 2 .2× 10 6L· mol-1· cm-1,铋含量在 4— 2 8μg/ 5 0 m L范围内符合朗伯 -比耳定律 ,平均回收率为 98.4 2 %,该体系络合稳定 ,灵敏度高、重现性好 ,用于人发样中铋含量的分析 ,结果令人满意。     

火焰原子吸收法测定钢铁中铅时阴离子表面活性剂的增感效应及其机理探讨

火焰原子吸收法测定钢铁中铅，采用0．2％十二烷基硫酸钠（SDS）和0．001mol／L硝酸介质，加入硫脲消除共存元素铋的干扰，铅的浓度在0—20μg／mL范围内服从比耳定律。方法检出限为0．10μg／mL，相对标准偏差为2．30％，回收率为97％—99％，样品测定结果令人满意。并对阴离子表面活性剂增感机理进行了探讨。     

同步镀铋膜差分脉冲伏安法测试土壤中铬

采用同步镀铋膜法修饰玻碳电极及差分脉冲溶出伏安法测试土壤中Cr。在优化的实验条件下,以KNO3为支持电解质,NaAc-HAc(pH=5.5)为缓冲溶液的铋膜上得到Cr溶出特征峰电位为-1.14V,线性方程为:I=0.0747C+0.31054,相关系数为0.9981,检出限为0.001μg/L,线性范围为0.01—60μg/L,RSD=2.47%,该方法简单快速,准确度和精密度均符合要求,回收率为96.7%—104.5%。     

同位镀铋膜电极测定爆米花中的痕量铅

采用同位镀铋膜法修饰铂电极,用差分脉冲溶出伏安法对爆米花中痕置铅进行了测定,并优化了实验条件.在优化的实验条件下,分别对2.0×10<'8>-6.0×10<'-7>mol/L和6.0×10<'-7>-1.0×10<'-4>mol/L的pb<'2+>进行了测定,Pb<'2+>溶出峰电流与Pb<'2+>浓度呈良好的线性关系...     

铋酸钠催化大气压介质阻挡放电降解苯胺

在柱-板式介质阻挡放电体系中投加铋酸钠催化剂,研究了该体系的放电光谱特性及对苯胺模拟废水的协同处理效果,考察了pH 值、苯胺初始质量浓度及催化剂投加量等因素对降解率的影响,探讨了铋酸钠协同介质阻挡放电(DBD)催化降解苯胺的机理。实验结果表明,柱-板式电极结构放电过程中辐射出了紫外光和可见光,300~450 nm之间出现高强度N2第二正带谱线。初始浓度100 mg/L苯胺废水被处理10 min后,投加0.2 g/L催化剂时溶液的TOC去除率最高,比单独DBD低温等离子体体系提高14.11%。在碱性条件下,苯胺和TOC的去除率均好于酸性和中性条件。XRD检测结果显示铋酸钠在反应前后峰值位置未发生明显改变。     

N-烯丙基-N''''-(氨基对苯磺酸钠)硫脲光度法测定微量铋(Ⅲ)

新显色剂N-烯丙基-N'-(氨基对苯磺酸钠)硫脲(ASATu)与铋(Ⅲ)在酸性介质中能形成稳定的1:3黄色水溶性络合物,最大吸收波长在350nm,摩尔吸光系数为6.3×104L·mol-1·cm-1;铋量在0-4.2mg/L范围内服从比耳定律,相关系数为0.9994.此法显色稳定,选择性好,操作简单.用于合金样品及合成工业废水中铋的测定,均获得满意结果.     

氢化物发生-原子荧光光谱法检测烟草中痕量砷和铋

用硝酸-高氯酸混合酸消解烟样,氢化物发生-原子荧光光谱法(HG-AFS)测定烟草中的砷、铋等重金属,对前处理酸的用量,样品介质(盐酸)、预还原剂等进行了试验,平行测定烤烟和杀青烟叶样品11次的相对标准偏差为As:1.62%-5.01%,Bi:5.38%-10.13%;方法的检出限为As:0.079μg·L-1,Bi:0.381μg·L-1;检测的线性范围As:0.0-60.0μg·L-1,Bi:0.0-8.0μg.L-1;加标回收率为As:86.7%,Bi:108.0%,测定结果令人满意.     

铋膜电极差分脉冲溶出伏安法测定痕量镉

研究了用铋膜电极测定痕量重金属元素镉的差分脉冲溶出伏安法,并对实验条件进行了优化。结果表明：铋膜电极可以获得和汞膜电极类似的良好溶出峰,且电极重现性好。在优化的实验条件下,镉离子的氧化峰电流与镉离子的浓度在10—440μg.L-1的范围内呈线性关系,检出限为4.66μg.L-1。铋膜电极优异的电化学性能加上低毒性,使其可以用来测定环境和工业中的镉。     

基体溶液改进-原子荧光法测定食品中的汞

探讨改进基体溶液双道原子荧光光谱法测定食品样品中的汞。样品消解后用6mol/L盐酸、硫脲+抗坏血酸(50g/L)作为基体溶液进行仪器测定。本方法检出限0.051μg/g,最低检出质量浓度0.10μg/L,相对标准偏差为7.45%、6.76%,回收率为88.6%—113.2%。方法具稳定性好、灵敏度高、检出限低等优点。     

多壁碳纳米管/铋膜修饰电极示差脉冲溶出伏安法测定水中镉和铅

制备多壁碳纳米管/壳聚糖纳米复合物修饰玻碳电极,用于同位镀铋膜法连续测定水中镉和铅离子的含量.将多壁碳纳米管分散在壳聚糖溶液中,滴涂在玻碳电极表面制得修饰电极;在含铋的溶液中,采用示差脉冲溶出伏安法测定了镉、铅离子的浓度;考察了沉积电位、富集时间对溶出电流的影响.在优化的实验条件下,对浓度在0-0.2μmol/L范围内...     

ICP—AES法直接测定铋矿石中铋

本文研究了用ＩＣＰ－ＡＥＳ法直接测定铋矿石中铋含量的方法，优化了仪器的测试条件，并对共存元素的干扰情况进行了研究，该方法简便，快速，可直接用于铋矿石中铋的准确测定，结果满意。     

苯酚红褪色分光光度法测定小麦粉中的痕量溴酸钾

对苯酚红褪色分光光度法测定小麦粉中痕量溴酸钾进行了研究。实验考察了各种因素如酸度、苯酚红的浓度和用量、反应时间和温度等对测定的影响。结果表明,在最优化的实验条件下(最大吸收波长为504nm,0.5mol/L盐酸,1.00mL 1.00×10-4mol/L苯酚红,85℃水浴条件下加热10min),溴酸钾在0—0.45μg/mL范围内符合比耳定律,线性回归方程为ΔA=0.6094C-0.0013(C:μg/mL,相关系数r=0.9991),摩尔吸光系数ε=3.6×106L.mol-1.cm-1,检出限为0.01μg/g(取样量5g)。将该法用于小麦粉中痕量溴酸钾的测定,样品加标回收率在93%—103%,相对标准偏差RSD<5%,结果满意。     

Photoacoustic Spectroscopy of Strongly Absorbing Solids: Bismuth Tri-Iodide

We found a need to optically characterize bismuth tri-iodide, BiI₃, which has been used in antireflective thin film coatings on potassium chloride laser windows. We received a 7mm thick, 18mm diameter disc shaped sample of BiI₃ which exhibited a dark gray, glassy, metallic appearance. Several commercial spectrophotometers in the laboratory showed it to be opaque from 0.3μm to 50μm. We therefore decided to see if relevant optical data could be obtained on the sample using an in-house built photoacoustic spectrometer.     

Dielectric and relaxation properties of thermally evaporated nanostructured bismuth sulfide thin films

Nanostructured bismuth sulfide thin films were prepared onto glass substrates with particle size of 21 nm by thermal evaporation using readily prepared bismuth sulfide nanocrystallite powder. The X-ray diffraction pattern revealed that bismuth sulfide thin films exhibit orthorhombic structure. The existence of quantum confinement effect was confirmed from the observed band gap energy of 1.86 eV. AC and DC electrical conductivity of Al/BiSnc/Al structures was investigated in the frequency range 0.5-100 kHz at different temperatures (303-463 K) under vacuum. The AC conductivity (σ_ac) is found to be proportional to angular frequency (ω^s). The obtained experimental result of the AC conductivity showed that the correlated barrier hopping model is the appropriate mechanism for the electron transport in the nanostructured bismuth sulfide thin films. DC conduction mechanism in these films was studied and possible conduction mechanism in the bismuth sulfide thin films was discussed.     

Bismuth silicate glass containing heavy metal oxide as a promising radiation shielding material

Optical and FTIR spectroscopic measurements and electron paramagnetic resonance (EPR) properties have been utilized to investigate and characterize the given compositions of binary bismuth silicate glasses. In this work, it is aimed to study the possibility of using the prepared bismuth silicate glasses as a good shielding material for γ-rays in which adding bismuth oxide to silicate glasses causes distinguish increase in its density by an order of magnitude ranging from one to two more than mono divalent oxides. The good thermal stability and high density of the bismuth-based silicate glass encourage many studies to be undertaken to understand its radiation shielding efficiency. For this purpose a glass containing 20% bismuth oxide and 80% SiO₂ was prepared using the melting–annealing technique. In addition the effects of adding some alkali heavy metal oxides to this glass, such as PbO, BaO or SrO, were also studied. EPR measurements show that the prepared glasses have good stability when exposed to γ-irradiation. The changes in the FTIR spectra due to the presence of metal oxides were referred to the different housing positions and physical properties of the respective divalent Sr²⁺, Ba²⁺ and Pb²⁺ ions. Calculations of optical band gap energies were presented for some selected glasses from the UV data to support the probability of using these glasses as a gamma radiation shielding material. The results showed stability of both optical and magnetic spectra of the studied glasses toward gamma irradiation, which validates their irradiation shielding behavior and suitability as the radiation shielding candidate materials.     

流动注射-氢化物发生-原子吸收光谱法测定果胶铋

本文采用流动注射 氢化物发生 原子吸收光谱法测定了果胶铋中铋的含量 ,方法简单、快速、准确 ,考察了实验参数对测定果胶铋中铋的影响。线性范围为 0 0 0～ 4 4 0 0ng·mL- 1 ,工作曲线回归方程为A =0 0 12 +0 0 17c(c:ng·mL- 1 ) ,相关系数r=0 9995 ,检测限为 0 0 95ng·mL- 1 ,回收率在 97 3%～ 10 3 3% ,用于实际样品的分析结果满意。