煤燃烧脱硫过程中含硫阴离子的离子色谱分析

建立了煤燃烧脱硫过程中主要含硫阴离子及常见无机阴离子的快速离子交换色谱分离和定量方法。以 0 .8mmol/L邻苯二甲酸氢钾作流动相 ,非抑制型电导检测法检测SO32 - 和SO42 - 的下限浓度分别为 0 .5mg/L和 1 .0mg/L。所建立的分析方法被用于脱硫方法的研究。同时 ,验证了甲醛溶液作为SO32 - 保护剂的机理是甲醛与SO32 - 形成了稳定的配合物。     

新合成\"哥腊\"衍生试剂在甲醛的电分析化学中的研究

利用合成新的Ｇｉｒａｒｄ’ｓ试剂Ｔ,使之与甲醛反应生成电活性的产物,在银基汞膜电极上不原来检测甲醛。对影响这一测定方法的各种因素进行了研究,指出了最佳的实验条件,探讨了衍生反应和电极过程。应用这一方法测定浓度为５．０×１０＾－６ｍｏｌ／Ｌ的甲醛,重现性良好,其ＲＳＤ为３．０５％;对浓度为２．０１０＾－７ｍｏｌ／Ｌ的甲醛测定７次,其检测限为７．６×１０＾－８ｍｏｌ／Ｌ。     

污染物甲醛为电子给体Pt/TiO2光催化制氢

研究了甲醛为电子给体在Pt/TiO2上光催化生成氢的反应。甲醛经光催化降解产生CO2和甲酸,甲酸可进一步被氧化;甲醛的光催化降解与放氢同时发生,催化剂的最佳Pt负载量为0．5％,甲醛浓度对反应的影响,表观上符合Langmuir-Hinshelwood关系式;碱性条件有利于该反应;在甲醛浓度较低时,甲醇的存在能部分地提高放氢速率,并讨论了可能的反应机理。     

MoO_3·B_2O_3／SiO_2催化剂上甲烷选择氧化制甲醛

ＭｏＯ_３·Ｂ_２Ｏ_３／ＳｉＯ_２催化剂上甲烷选择氧化制甲醛曹立新,陈燕馨,李文钊（中国科学院大连化学物理研究所,大连１１６０２３）关键词甲烷,氧化,甲醛,催化剂。１．前言目前工业上由甲烷合成甲醛共需三个步骤：（１）在Ｎｉ催化剂上甲烷进行“水蒸汽重整”...     

Determination of multiple phenolic compounds in infant textile products by derivatization gas chromatography-mass spectrometryEI北大核心CSCD

A method for the simultaneous determination of 17 phenolic compounds in infant textile products, including phenol,o-phenylphenol,alkylphenols and bisphenols,was established using gas chromatography-mass spectrometry（GC-MS）. The samples were extracted by 0.1 mol/L KOH solution,derived with acetic anhydride. The derivatives were extracted with ethyl acetate,separated by HP-5MS column,and determined by gas chromatography-mass spectrometry with ion mode scanning. Under the optimized conditions,the method had a good linear relationship in the range of 0.5-6.25 mg/L（R2>0.9990）,the recoveries ranged from 80% to 110%, the relative standard deviations were 1.0%-8.6%,and the limit of quantification was 1.0 mg/kg. The method can achieve the simultaneous detection of 17 phenolic compounds in infant textile products. © 2023, Youke Publishing Co., Ltd. All rights reserved.     

基于QDOAS的多轴差分吸收光谱测量对流层HCHO的研究

由于甲醛在大气光化学反应中的重要性及其对环境、气候和人类健康的危害,监测、有效控制甲醛浓度已经成为一件刻不容缓的要事。目前传统的监测多局限于基于化学方法、色谱法的室内监测,或是室外较小范围的监测,室外大范围的大气中的甲醛监测往往为人们所忽视。为了有效监测大气中大范围的甲醛（HCHO）浓度,建立了地基MAX-DOAS观测系统,与主动DOAS观测系统相比,该观测系统不受光源和反射装置限制,平台搭建简单,测量范围广。2018年在合肥地区(117°17′E, 31°90′N)夏季开展了基于地基MAX-DOAS的外场连续观测实验,结合新一代光谱处理软件QDOAS利用DOAS算法的非线性最小二乘拟合反演甲醛（HCHO）的斜柱浓度,并通过大气质量因子（AMF）将甲醛（HCHO）的斜柱浓度转换为柱浓度,并分析了7月份的观测数据,结果表明,低仰角下甲醛的差分斜柱浓的值较高,说明,对流层甲醛主要集中在接近地表的位置。从实验数据还可以看到,二氧化氮与甲醛的变化趋势基本一致,说明大气中的甲醛与机动车排放或是工业排放出的的氮氧化物（NO₂等）在大气的源与汇过程中具有一定的相关性。通过地基MAX-DOAS测量数据与OMI观测值的比较发现,二者的变化趋势具有良好的一致性,且相关系数为0.518 9,并分析了OMI观测值偏低的原因。研究结果表明,地基MAX-DOAS系统不仅可以对区域污染的演变进行研究,也为甲醛的测量提供了一种实时、快速的监测手段,为分析大气甲醛的来源提供了一种新的解析手段,为验证卫星观测数据提供了一种有效的手段。     

表面桥氧空位对甲醛在二氧化钛表面吸附的影响

Oxygen vacancy (O_v) has significant influence on physical and chemical properties of TiO₂ systems,especially on surface catalytic processes.In this work,we investigate the effects of O v on the adsorption of formaldehyde (HCHO) on TiO₂(110) surfaces through firstprinciples calculations.With the existence of O_v,we find the spatial distribution of surface excess charge can change the relative stability of various adsorption configurations.In this case,the bidentate adsorption at five-coordinated Ti (Ti_5c) can be less stable than the monodentate adsorption.And HCHO adsorbed in O_v becomes the most stable structure.These results are in good agreement with experimental observations,which reconcile the long-standing deviation between the theoretical prediction and experimental results.This work brings insights into how the excess charge affects the molecule adsorption on metal oxide surface.     

表面羟基辅助甲醛分子在金红石型TiO2(110)表面迁移动力学研究

As the photo-dissociation product of methanol on the TiO₂(110) surface,the diffusion and desorption processes of formaldehyde (HCHO) were investigated by using scanning tunneling microscope (STM) and density functional theory (DFT).The molecular-level images revealed the HCHO molecules could diffuse and desorb on the surface at 80 K under UV laser irradiation.The diffusion was found to be mediated by hydrogen adatoms nearby,which were produced from photodissociation of methanol.Diffusion of HCHO was significantly decreased when there was only one H adatom near the HCHO molecule.Furthermore,single HCHO molecule adsorbed on the bare TiO₂(110) surface was quite stable,little photo-desorption was observed during laser irradiation.The mechanism of hydroxyl groups assisted diffusion of formaldehyde was also investigated using theoretical calculations.