微顺序注射-镉柱还原分光光度法测定海水中总氮

基于微顺序注射-阀上实验室,采用镉柱还原-偶氮染料染色分光光度法测定海水中总氮,对实验参数进行了优化,并进行了干扰因素实验。结果表明,海水中主要离子和盐度对本实验方法测定会产生干扰,采用一定盐度的国家标准海水作为溶剂制备系列标准溶液,可消除干扰。海水中总氮浓度在0.03~1.00 mg/L范围内与吸光度呈良好线性,线性相关系数r=0.9993;测定含氮浓度为0.2 mg/L的国家标准海水,相对标准偏差(RSD)为4.9％;方法的检出限为0.010 mg/L;样品加标回收率在99.5％~101.1％之间。经t检验分析,本方法与国标方法测定数据无显著性差异,可用于海水样品中总氮的测定。     

流动注射-光度法测定地表水中挥发酚

以国家标准GB/T 7490-1987及国际标准ISO 6439-1990中所述的测定方法及相关技术要求为基础,提出了应用流动注射技术的FI-光度法测定地表水中挥发酚的自动注程.按此改进后的方法,一次测定可在30 min以内完成.挥发酚的质量浓度在0.10 mg·L-1以内与吸光度之间保持线性关系(r=1.000 0),方法的检出限为0.001 mg·L-1,通过分析两件工作标准样品,对方法的精密度和准确度作了考核,所得测定结果与标准值相符,相对标准偏差(n=6)均小于2%.对方法的回收率作了试验,所得结果在101.5%～106.0%之间.     

固相萃取光度法测定烟草中的挥发酚

研究了用Waters Sep-Park-C18固相萃取小柱萃取测定烟草样品中的挥发酚的方法。用自动水蒸汽蒸馏仪蒸馏出烟草样品中的挥发酚，4-氨基安替比林显色，显色产物可用Waters Sep-Park-C18固相萃取小柱萃取，以乙醇洗脱后用分光光度法测定，该方法可用于烟草样品中挥发酚的测定。     

水中挥发酚的在线蒸馏-固相萃取分离富集及测定

在顺序注射系统中实现了挥发酚的快速自动在线蒸馏,并用AmberliteXAD-7树脂微填充柱对其与4-氨基安替比林的衍生物在线固相萃取,被富集的衍生物可用少量乙醇有效地洗脱回收,以分光光度法检测.方法可用于较高浓度挥发酚(mg/L)样品的测定,也可根据需要适当增大进样体积,经富集后实现更低浓度水平(μg/L)挥发酚的测定.当富集过程中进样体积为4mL时,方法测定挥发酚的线性范围为0.004~0.3mg/L,检出限为0.002mg/L,相对标准偏差为1.4%(0.1mg/L,n=9).对多种实际水样中的挥发酚进行了测定,加标回收实验的回收率在96%~102%之间.     

连续流动分析法测定土壤中的挥发酚

建立了连续流动分析仪测定土壤中挥发酚含量的方法。称取5 g左右的土壤样品,以磷酸调节p H值为4,加入适量水并进行蒸馏,馏出液用连续流动分析仪测定挥发酚含量。在4.96~200μg/L范围内,挥发酚的质量浓度与相对峰高线性相关,线性方程为y=235.31x+51.6,相关系数r~2=0.999 8,挥发酚的检出限为1.24μg/L。取2种土壤样品分别进行6次平行测定,测定结果的相对标准偏差分别为1.52%,1.56%。对2种挥发酚标准样品进行测试,相对误差分别为1.90%,2.08%,加标回收率在87.8%~95.5%之间。该方法适合大批量样品的连续分析,且无需使用三氯甲烷,与传统方法相比更安全环保。     

固相萃取光度法测定饮用水中挥发酚的研究

研究了用Waters Sep-Park-C18小柱固相萃取光度法测定饮用水中挥发酚的方法。水样中经水汽蒸馏分离后的挥发酚，用4－氨基安替比林显色，显色产物可用C18固相萃小柱萃取、乙醇洗脱后用分光光度法测定。方法污染小，操作简便，便于批量样品处理，用于饮用水中挥发酚的测定，结果令人满意。     

地质环境样品中挥发酚分析现状与进展

挥发酚被列为环境优先控制的有机污染物,已成为评价环境污染的重要指标之一。该文简述了挥发酚的化学性质及地质环境来源,概括了国内外挥发酚测定的相关标准方法,从样品预处理技术和检测技术两方面综述了近年来地质环境样品中挥发酚分析的研究现状。重点对溶剂萃取、蒸馏、固相萃取、固相微萃取和吹扫捕集等样品预处理技术,以及4-氨基安替比林分光光度法、紫外和荧光分光光度法、溴化容量法、气相色谱法、液相色谱法和酚生物传感器法等技术在地质环境样品中挥发酚分析上的应用进行了较为全面的总结,并对其未来的发展趋势进行了展望,为进一步研究挥发酚的分析技术及其环境应用提供参考。     

碱性过硫酸钾氧化法-紫外分光光度法测定养殖海水中总氮量

以国家标准GB/T 12763.4-2007中的碱性过硫酸钾氧化法和GB/T 11894-1989中淡水总氮测定的紫外分光光度法为基础对海水总氮测定方法进行了改进。在改进的方法中减少了物质转化步骤,相应减少了样品转移次数与定量移取步骤。该方法测定总氮量的线性范围在57.74mg·L-1(以KNO3计)以内。该方法的有机氮物质氧化率为(99.1±5.6)%,加标氧化率为(100.4±4.2)%,以海水样品为基体的加标回收率为(107.3±15.3)%。对海水样品及20,40μmol·L-1硝酸钾标准溶液的测得结果与已知值无显著差异。     

碱法提取–流动注射检测仪测定土壤中的挥发酚

采用流动注射检测仪测定土壤中的挥发酚含量,并研究前处理过程对实验结果的影响.20 g新鲜土壤样品中的挥发酚用200 mL 10 g/L氢氧化钠溶液超声提取,提取液过滤后采用流动注射检测仪测定土壤中的挥发酚含量.挥发酚的质量浓度在0～1.00 mg/L范围内与峰面积具有良好的线性关系,相关系数为0.9999,检出限为0....     

智能一体化蒸馏仪蒸馏-全自动流动注射分析仪测定底泥中挥发酚

采用碱液浸提底泥中挥发酚后,由于溶液浑浊,且存在干扰,若直接采用流动注射分析仪进行测定,极易堵塞仪器的管路,进而影响后续测定,故将提取液在酸性条件下加入硫酸铜于全自动智能一体化蒸馏器蒸馏,消除硫化物等的干扰,用全自动流动注射分析仪测定底泥中挥发酚。实验对磷酸、硫酸铜加入量、震荡时间、蒸馏功率和蒸馏体积进行了优化,并确定磷酸过量5mL,加入5g硫酸铜,震荡10min,蒸馏功率为50W,蒸馏重量设置为225g。标准曲线的线性关系良好,相关系数为0.999 9以上,样品和空白加标回收率在89.3%～103%,检出限为0.03mg/kg。实验方法测定底泥中挥发酚样品与传统分光光度法结果一致,不仅实现自动化,而且对环境和人均友好。     

Current Response of Cytochrome C Promoted by Dodecyl Benzene Sodium Sulfonate

Abstract

A simple TLC separation and semi-quantitative visual determination method was used to analyse the volatile phenols in the waste water of the petroleum industry and the grain irrigated by the waste water. The phenol in the rice irrigated by the water that contained phenol for artificial preparation was also studied. A preliminary conclusion was obtained, that the grain could absorb volatile phenols from irrigation water.     

过硫酸钾氧化4-氨基安替比林分光光度法测定地表水中挥发酚

在pH值为10.0±0.2的缓冲溶液中,以过硫酸钾溶液作氧化剂,用经乙醇和正己烷(1+4)混合溶液提纯的4-氨基安替比林(4-AAP)作显色剂,采用三氯甲烷分光光度法测定地表水中挥发酚.结果表明,经乙醇和正己烷(1+4)混合溶液提纯的4-AAP,损失较少,且纯度较高,有利于准确配制4-AAP溶液.此外,稳定、无色的过硫...     

Determination of Mercury and Thallium in Seawater by Electrothermal Vaporization Inductively Coupled Plasma Mass Spectrometry

Electrothermal vaporization inductively coupled plasma mass spectrometry (ETV‐ICP‐MS) has been applied to the determination of Hg and Tl in seawater samples. Various modifiers were tested for the best signal of these elements. After preliminary studies, 0.3% EDTA, 0.1%m/vTAC and 1% v/v HCl were added to the sample solution to work as the modifier. Since the sensitivities of Hg and Tl in various seawater matrices and aqueous standard solutions were quite different, standard addition method and isotope dilution method were used for the determination of Hg and Tl in these seawater samples. This method was applied to the determination of Hg and Tl in NASS‐4 and CASS‐3 reference seawater samples and seawater samples collected from the Kaohsiung area. Results obtained by isotope dilution method and method of standard additions agreed satisfactorily. Detection limits were in the range of 5‐15 and 0.4‐0.5 ng l^?1 for Hg and Tl in seawater, respectively, with the ETV‐ICP‐MS method. The precision between sample replicates was better than 18%) for all the determinations.     

石墨炉原子吸收法直接测定海水中铅的方法探索

目的探索石墨炉原子吸收法直接测定海水中铅的检测方法。方法用硝酸铵稀释海水样品,用硝酸钯和磷酸二氢铵作为基体改进剂,用石墨炉原子吸收法测定了海水中的铅含量。结果通过加标回收的验证,检测结果准确可靠。结论适合用于海水中铅含量的测定。     

Inhibition of Phenol from Entering into Condensed Freshwater by Activated Persulfate during Solar-Driven Seawater Desalination

Recently, solar-driven seawater desalination has received extensive attention since it can obtain considerable freshwater by accelerating water evaporation at the air–water interface through solar evaporators. However, the high air–water interface temperature can cause volatile organic compounds (VOCs) to enter condensed freshwater and result in water quality safety risk. In this work, an antioxidative solar evaporator, which was composed of MoS₂ as the photothermal material, expandable polyethylene (EPE) foam as the insulation material, polytetrafluoroethylene (PTFE) plate as the corrosion resistant material, and fiberglass membrane (FB) as the seawater delivery material, was fabricated for the first time. The activated persulfate (PS) methods, including peroxymonosulfate (PMS) and peroxodisulfate (PDS), were applied to inhibit phenol from entering condensed freshwater during desalination. The distillation concentration ratio of phenol (R_D) was reduced from 76.5% to 0% with the addition of sufficient PMS or PDS, which means that there was no phenol in condensed freshwater. It was found that the Cl⁻ is the main factor in activating PMS, while for PDS, light, and heat are the dominant. Compared with PDS, PMS can make full utilization of the light, heat, Cl⁻ at the evaporator’s surface, resulting in more effective inhibition of the phenol from entering condensed freshwater. Finally, though phenol was efficiently removed by the addition of PMS or PDS, the problem of the formation of the halogenated distillation by-products in condensed freshwater should be given more attention in the future.     

Application of dispersive liquid–liquid microextraction and gas chromatography with mass spectrometry for the determination of oxygenated volatile organic compounds in effluents from the production of petroleum bitumen

We present a new procedure for the determination of oxygenated volatile organic compounds in samples of postoxidative effluents from the production of petroleum bitumens using dispersive liquid–liquid microextraction and gas chromatography with mass spectrometry. The eight extraction parameters were optimized for 43 oxygenated volatile organic compounds. The detection limits obtained ranged from 0.07 to 0.82 μg/mL for most of the analytes, the precision was good (relative standard deviation below 2.91% at the 5 μg/mL level and 4.75% at the limit of quantification), the recoveries for the majority of compounds varied from 70.6 to 118.9%, and the linear range was wide, which demonstrates the usefulness of the procedure. The developed procedure was used for the determination of oxygenated volatile organic compounds in samples of raw postoxidative effluents and in effluents after chemical treatment. In total, 23 compounds at concentration levels from 0.37 to 32.95 μg/mL were identified in real samples. The same samples were also analyzed in the SCAN mode, which resulted in four more phenol derivatives being identified and tentatively determined. The studies demonstrated the need for monitoring volatile organic compounds content in effluents following various treatments due to the formation of secondary oxygenated volatile organic compounds.