梯度淋洗离子色谱法同时测定雨水中12种有机酸和无机阴离子的研究

研究了用离子色谱梯度洗脱-抑制电导检测器同时分离12种有机酸和无机阴离子的规律和色谱务件,建立了最佳梯度程序.在所选实验务件下,方法对所测有机酸和无机阴离子的线性相关系数为0.9929～0.9998,相对标准偏差为4.2%～9.3%,加标回收率为91.4%～107.0%,最低检测限为0.0069～0.34mg/L.方法用于雨水样品的测定,结果令人满意.  

A Global Overview of Atmospheric Acid Deposition Fluxes

This paper presents a summary of globalacid deposition flux data taken from a globalassessment report on acid deposition prepared forUNEP/WMO (Whelpdale and Kaiser, 1996). There is a largevariation in the spacial coverage and reliability ofmonitoring around the world. Many more stationsmeasure wet deposition than collect appropriate datafor estimating dry deposition. The widespread regionswith highest precipitation concentrations anddeposition fluxes of sulphate and nitrate coincideclosely with the regions of highest density ofSO₂ and NO_x precursor emissions occurringprimarily in the mid-latitude, northern hemispherebelt where a large fraction of the worlds fossilfuels is consumed. Organic acids in precipitation makea minor contribution to acidity (<20%) inindustrial regions, but in the rest of the world theyare of same order, or even exceed, inorganic acids.Less is known about dry deposition, but it appears topredominate near strong emission sources with wetdeposition predominating farther downwind. The molarratio of the N/S contribution to acidic deposition isclose to 1.0 over large areas of Europe and NorthAmerica, but is highly variable elsewhere, beinghighest in equatorial regions due to biomass burningand lowest near smelters and other large sources of SO₂.  

离子色谱法测定污泥与餐厨垃圾联合厌氧发酵液中有机酸

采用离子色谱法同时测定污泥与餐厨垃圾联合厌氧发酵液中乳酸、乙酸、丙酸、正丁酸、异丁酸、正戊酸、异戊酸等7种有机酸，通过试验优化洗脱程序，使得7种有机酸在2．00mg／L～60．0mg／L范围内线性良好。试验表明，方法检出限为0．250mg／L～0．580mg／L，标准样品的加标回收率为93．O％～108％，8次测定结果的RSD为3．7％一7．1％，实际样品测定的加标回收率为90．6％～109％。  

离子色谱法同时测定大气PM2.5中水溶性有机酸和无机阴离子的研究

建立超声提取-离子色谱法55 min内同时测定大气PM_2.5中13种水溶性低分子有机酸和无机阴离子的方法，经不同样品膜空白值考察、预处理条件优化、样品保存实验研究等获得了最佳的实验条件。研究发现，无机阴离子线性回归系数均为0.999以上，有机酸均为0.993以上；样品膜中各离子的相对标准偏差为3.2%~9.8%，样品提取液中各离子的加标回收率为90.6%~108%；当采样体积为24 m³时，各目标化合物的方法检出限为0.003~0.032 μg/m³。分别于2015年1、6月采集了PM_2.5实际样品，1月各离子浓度之和为31.9 μg/m³，范围为0.04~15.0 μg/m³；6月各离子浓度之和为22.3 μg/m³，范围为0.01~12.7 μg/m³。两个采样期间，氯离子、硝酸根、硫酸根在13种化合物中占绝对优势，均占总量的95%以上；乙酸、甲酸、甲烷磺酸和乙二酸为其他低含量离子中的主要组分。  

棕壤吸附-解吸铬影响因素研究

采用室内实验方法,研究了不同铬浓度及不同pH对棕壤吸附-解吸铬的影响,草酸、EDTA和柠檬酸3种有机酸在不同浓度、不同pH条件下对棕壤吸附-解吸铬的影响。结果表明,棕壤对Cr6＋的吸附率随其浓度的增大逐渐增大,并在酸性条件下易于吸附Cr6＋,在碱性条件下易于解吸Cr6＋,低浓度有机酸有利于棕壤对Cr6＋的解吸。EDTA解吸率最大,草酸次之,柠檬酸最小。