苏州景观河道表层沉积物间隙水-上覆水中DOM特性分析

为了解苏州景观河道间隙水和上覆水中溶解性有机物(DOM)的特性和相互关系,利用紫外-可见吸收光谱、高效液相色谱和荧光光谱结合荧光区域积分法,分析了苏州城区自2020年汛期过后,7～9月景观河道沉积物间隙水和上覆水中的DOM的特性.结果表明,间隙水和上覆水中DOM的相对分子质量均为1 000左右,且随着时间的推移,相对分...     

荧光传感器阵列检测农药污染物研究进展

农药的滥用已造成严重的环境污染,因此开发高效、简便和灵敏的农药检测技术是环境科学领域的研究焦点.荧光传感检测因其灵敏度高,检出限低,操作简单,成本低,目前已逐渐成为农药快速定量检测的一个发展方向.然而,在真实样品检测环境中,污染物不是单独存在的,常伴随结构或化学性质上与待检测分析物相似的污染物进行干扰.而基于阵列的荧光...     

基于吡啶甲基萘酰亚胺的水中痕量铁检测方法研究

合成了一种新型的荧光分子探针N-(2-吡啶甲基)-1,8-萘酰亚胺(PMN),研究了其在环境水样中痕量铁离子的检测应用.结果表明,该方法选择性好,灵敏度高,操作简便,且常见金属离子不干扰测定.Fe3+浓度在1×10-7~8×10-5mol/L范围内,荧光强度与其浓度呈良好的线性关系.方法用于自来水、井水、生活污水中痕量铁的测定,回收率在95.78%~104.02 %之间.     

Mineralogy and chemistry of urinary stones: patients from North Jordan

Urinary stone diseases are increasing in the Middle East. The majority of urinary stone cases are found in the northern part of the country. Stone samples taken from patients living in the Irbid area were collected from Princess Basma Hospital. The present study concentrates on the mineralogical and chemical composition of the urinary stones and on the effective environmental factors that assist in developing the different types of urinary stones. Using X-ray diffraction techniques, the mineralogical composition of the urinary stones was found to be as follows: oxalate, cholesten, and uric acid, with cystine stones occuring more frequently than the others. Cholesten and calcium oxalate stones are the most dominant types of stones. Calcium oxalate is the most common type of oxalate stone. Calcium oxalate is represented in: whewellite, wheddellite, and calcium carbonate oxalate hydrate minerals, in addition to other minerals such as brushite, ammonium phosphate, vaterite, valleriite, and bobierrite from other types of stones. Bobierrite (phosphate group) is a new mineral reported in urinary stones, and this has not been determined in any previous study worldwide. Apatite (calcium phosphate) is deduced using scanning electron microscope (SEM) images. The SEM technique determined crystal forms and systems, shapes, morphological features, and the names of the minerals forming urine stones, while optical properties are studied by polarizing microscope. X-ray fluorescence technique determined the concentrations of major and some trace elements. It revealed that Ca is the main constituent of the urinary stones, especially those composed of calcium oxalate and calcium phosphate. The concentration of trace elements was Ba = 1.57, P = 3.61, Fe = 1.78, S = 2.08, Zr = 4.63, Mo = 3.92, Cu = 1.89, Co = 1.56, and F = 4.2% and was higher in the urinary stones of Jordanian patients than in foreigners in the country. Questionnaires completed by patients suggest that the most significant factors directly effecting the formation of stones are water, climate conditions, food rich in protein and rich in different chemicals. Moreover, some drugs and diseases might also help in developing other stones.     

Pesticide dispersion by spraying under tropical conditions

Pesticide air pollution by spraying was evaluated under different temperature, humidity and wind climatic conditions in Brazil. Field experiments were performed with application towards the soil and in guava orchards, where spray dispersion was monitored by adding p-aminobenzoic acid (PABA), a fluorescent substance, as a tracer to the water contained in the spray tanks. Samples were collected with filter membranes (Whatman 180025), and the PABA was extracted from the filters by shaking with water in a Petri dish and measured in a spectrofluorometer. A spray aimed towards the soil with filters positioned on the ground and hung at different heights did not show different upward dispersion as observed when lateral pulverization was conducted. In this case, a tractor with a sprayer moved through a 3 m high and 6 m wide frame with filter membranes mounted at 60 cm intervals. Spray dispersion patterns were modified by guava leaf resistance. No influence of temperature and humidity was observed in this short-lived spraying process. Nevertheless, wind drift can occur during airborne dispersion and is an important pesticide pollution source which requires control. Droplets with PABA powered by assisted spraying upwards returned to the ground by gravity and, therefore, did not constitute a vertical source of atmospheric pollution.     

便携式XRF土壤重金属检测仪在环境应急监测中的应用探讨

系统评估了便携式XRF重金属检测仪的精密度、准确度及测定影响因素,开展了该方法测定土壤中Cu、Zn、As、Pb、Cr与国标分析方法的系统比对。结果表明:上述5种元素的方法检出限为5.7 mg/kg~16.0 mg/kg,土壤标准样品测定6次结果的RSD为1.0%~4.7%,Zn、Pb和As测定结果的相对误差10%;与国标法相比,便携式XRF重金属检测仪测定Cu、Zn、As、Pb的准确度较好,测定Cr的准确度波动较大。将该方法用于应急污染事故监测,可迅速锁定污染物及污染区域,实现野外分析的预判。     

微波消解-原子荧光光谱法测定大气PM2.5中的砷

采用微波消解-原子荧光光谱法测定大气细颗粒物中的砷,确定了最佳样品处理方法与测定条件。方法在0μg/L～40．0μg/L范围内线性良好,标准曲线相关系数达0．999以上,检出限为0．01μg/L。土壤标准品的测定值在标准值范围内,大气PM2．5滤膜样品加标回收率为96．0％～102％,5次平行测定的RSD为1．5％～3．6％。     

基于X射线荧光分析原理的大气重金属在线分析仪的维护与质控

近年来大气细颗粒物中重金属元素成分的监测是细颗粒物化学成分监测的热点之一,这一类物质的在线监测在国内应用越来越多,笔者研究和探讨了影响X射线荧光法大气重金属在线分析仪器运行质量的主要运维工作和质量控制方法,提出了该仪器在线监测中的运维及质控要求,为环境监测工作者提供参考,以获得更加准确的监测数据。     

原子荧光法测定土壤中砷的质量控制评价标准研究

组织多家实验室开展监测,研究了原子荧光法测定土壤中砷的质量控制措施及其评价标准。研究表明,RSD、RD、RSD'、RD'、RE和加标回收率是土壤监测的重要质量控制措施,对于标准样品,其评价标准分别为RSD≤10%、RD≤30%、RSD'≤20%、RD'≤30%、RE≤±20%、空白加标回收率为95%~105%、标准样品加标回收率为75%~110%;其与两个土壤标准样品系列、与土壤中砷的浓度均没有显著的相关性。     

原子荧光法测定土壤中的痕量碲

建立了采用微波消解土壤样品,OnGuardⅡH柱消除消解液中金属元素干扰,原子荧光法测定土壤中碲的方法。本方法检出限为0.009μg/g,加标回收率为91.3%~97.8%,具有操作简便、快速、准确度高和用酸量少等优点,有一定的应用价值。