悬浮液进样石墨炉原子吸收法直接测定土壤、底泥中的铅、镓、钴、镍

介绍一种悬浮液进样直接测定土壤、底泥中多种微量金属元素的快速分析方法。基体改进剂的使用，适宜的原子化温度的选择，使用水相标准溶液作校准曲线成为可能．对标准作品的测定证明了此方法的精密度和准确度较好，适合于常规环境样品分析．     

Leaf area development, dry weight accumulation and solar energy conversion efficiencies of Phaseolus vulgaris L. under different soil moisture levels near Nairobi, Kenya

Leaf area development, dry weight accumulation and solar energy conversion efficiencies of Phaseolus vulgaris L. cv GLP-2 under two soil moisture levels in two contrasting seasons near Nairobi, Kenya were investigated. The experiment confirms that dry weights and yields of Phaseolus vulgaris are limited by a drought induced decrease in leaf area, leading to less radiation interception as a source for assimilation. However, photosynthetic efficiency in Phaseolus vulgaris also appears to decrease and to contribute to these effects. Finally, an even larger decreases of economic efficiency as obtained in the second season, where stress lasted much later into the season, reveals that such a drought also limits considerably the partitioning and translocation of assimilates to the seeds of Phaseolus vulgaris. The efficiencies obtained are in line with the better literature data for other crops.     

氢化物发生-原子荧光法测定一次性餐具中砷

建立了一次性餐具中砷的氢化物发生－原子荧光测定方法，在选定的试验条件下，荧光强度与砷质量浓度在0μg/L－180μg/L范围内呈线性关系，相关系数0．999 3，溶液检测限0．5μg/L，回收率96％－101％。     

炼油企业挥发性有机物无组织排放通量监测现状与发展

炼油企业是重要的挥发性有机物(VOCs)人为排放源,排放的VOCs主要来自无组织源,监控及排放核算困难。笔者总结了国内外炼油企业VOCs排放通量监控及核算技术体系,综述了各类VOCs无组织排放通量监测技术的原理及适用范围,着重评述了工业场地VOCs无组织排放通量监测最佳实用技术——红外掩日通量监测(SOF)和差分吸收激光雷达(DIAL)及其在炼油企业的应用进展。总体上,SOF仪器及监测费用适中,但易受阳光等天气条件限制; DIAL几乎可全天候监测,但仪器及监测费用较高。SOF和DIAL监测的欧美炼油企业VOCs排放系数一般为0. 02%～0. 10%,约为排放清单值的3～10倍。国内炼油厂VOCs排放核算采用的排放系数约为美国排放清单值(0. 01%～0. 02%)的10倍,尚待实测校验和修订。VOCs无组织排放通量监测技术也可用于检查或评估炼油企业泄漏检测与修复(LDAR)等VOCs无组织排放控制效果。     

Heavy metals in Jamaican surface soils

A regional survey of Jamaican surface soils has been conducted in which more than 200 samples were collected at a sample density of 1 per 64 km² across the island and analysed for total concentrations of 31 elements by instrumental neutron activation analysis (INAA), energy dispersive X-ray fluorescence (EDXRF) analysis and atomic absorption spectrophotometry (AAS). The aim of the survey was to begin the construction of a high-precision geochemical database to provide information on elemental levels in soils for application to environmental studies, agriculture, and human and animal health. Results on the regional scale are presented for As, Cd, Cu, Hg and Pb. Although Jamaican surface soils are enriched in several heavy metals compared with world soil means and crustal abundances, lead is of particular importance at this stage because of its occurrence in residential areas. Except for Cu, the distribution maps of these elements are highly correlated with bauxite which in Jamaica is associated with white limestone geology and residualterra rossa soils.     

Nafion交换剂富集-石墨炉原子吸收法测定废水中铬

本文用Nafion交换剂富集-石墨炉原子吸收法测定废水中的Cr(Ⅲ)和Cr(Ⅵ),富集底液选用0.01mol NaAc-HAc缓冲液(pH=4.5),测定线性范围为5—100ng/ml,回收率在92—106％之间。对含Cr(Ⅲ)量为25ng/ml试样溶液进行十次平行测定,相对标准偏差为5.9％,特征浓度为2.4ng/ml Cr(Ⅲ),十多种共存离子不干扰测定。     

用空气-硝酸活性炭-碱吸收法净化NOx废气

本文研究淀粉法生产草酸过程中排放的NO_x废气的处理。先用空气做氧化剂,提高废气中NO_x的氧化度,并经水吸收,可产生13％硝酸,其后在催化剂存在下,用此酸反复喷淋吸收NO_x,使NO_x转化为41％的硝酸。此酸可回收作为淀粉法生产草酸的原料。本文还研究了影响喷淋吸收的因素,如喷淋吸收剂的温度、浓度和喷淋速度以及催化剂品种、粒径大小,并得出喷淋吸收的最佳条件。     

火焰原子吸收分光光度法测定总铬

研究了用火焰原子吸收分光光度法直接测定水和废水中的总铬。通过不同条件的实验 ,确定了最佳的分析条件 ;并通过标准样品和实际样品的分析 ,验证了方法的准确度和精密度。在实验基础上 ,建立空白试验、准确度质量控制图 ,以便定期对各种监测数据提供可行的质量保证措施。实验结果表明 :该法快速方便 ,提高了分析效率 ,准确度高 ,精密度好 ,值得普及和推广     

离子色谱／氢化物发生／原子吸收法测定天然淡水中的4种砷形态

首次用国产YSA－Ⅲ型阴离子交换树脂色谱柱,以离子色谱／氢化物发生／原子吸收联用方法,测定天然淡水中４种主要砷形态：亚砷酸盐,砷酸盐,甲基胂酸盐和二甲基胂酸盐。检出限依次为0.28,0.50,0.12和0.18ppbAs,较低于同类方法。实际水样2ngAs/mL加标回收率为93.0％～107.8％。给出几种淡水样中砷形态的分析结果。     

萃取富集—火焰原子吸收法测定环境水中痕量砷

联合应用高效雾化器、缝式石英管火焰原子吸收法,采用萃取富集技术测定砷,使砷的灵敏度改善267倍,同时消除了大量盐类的干扰,避免了钠、铝等对石英管的损坏。考察了溶液酸度、碘化钾用量、共存离子等因素对实验的影响。该方法的线性范围为0～25μg／L,检出限为。3μg／L,相对标准偏差为3．2％,回收率为97．8％～101．0％,用于环境水样中痕量砷的监测,结果令人满意。