溴甲酚绿──甲基红分光光度法测定空气中的痕量氨

本文研究了用溴甲酚绿－甲基红分光光度法测定空气中的痕量氨。在５ｍｌ吸收液中氨浓度０－２．７２μｇ／５ｍｌ遵守比尔定律。表观摩尔吸光系数ε＇６１５＝１．５５×１０４Ｌ／ｍｏｌ·ｃｍ。在采样过程中，吸收液颜色由红变绿。     

溴氧化甲基红褪色光度法测定大气中游离溴

利用溴(Br2)能氧化甲基红溶液并使其褪色,褪色程度与溴量呈线性关系的原理,通过对溶液酸度、各试剂用量等反应条件和可能存在的干扰进行了研究,建立了一种测定大气中游离溴的分析方法.方法的检出限为0.25μg/10ml,摩尔消光系数ε=3.9×104,线性范围为0～16μg/10ml.分别测定含溴量为2.4μg和5.60μg,结果表明,相对标准偏差在6.7%和5.0%(n=9)之间,相对误差小于7.0%.     

Determination of methyl tert-butyl ether (MTBE) in Chinese fuels by gas chromatography/mass spectrometry and gas chromatography/flame ionization detector

A method was developed to determine the concentration of methyl tert-butyl ether(MTBE) in gasoline,diesel and heating oil by gas chromatography(GC) with mass spectrometry(GC-MS) or flame ionization detection(FID). The diluted gasoline was directly injected into the GC, and the complete separation of MTBE from co-eluting hydrocarbons was not required. GC/MS or GC/FID method can be used to analyze MTBE in different concentration range and have good consistency.     

甲醇燃料发动机排气中的亚硝酸甲酯和硝酸甲酯的分析

为了测定使用甲醇燃料的发动机排气里的亚硝酸甲酯(MeONO)和硝酸甲酯(MeONO_2)含量,建立了色谱分析方法。本方法的最小检测限MeONO为20ppb,MeONO_2为50ppb。对自制的MeONO和MeONO_2进行了质谱鉴定,并对所制备的一定浓度的样品进行了稳定性考察。应用本方法测定了甲醇机排气中的MeONO含量为5ppm—250ppm,MeONO_2含量为<50ppb。     

A semipermeable membrane equilibrator for halomethanes in seawater

An equilibrator for sampling the partial pressures of halomethanes in seawater was designed and built, incorporating semipermeable membrane tubing to carry the gas phase. The equilibrator was tested for its ability to equilibrate chloromethane, bromomethane, iodomethane, and CFC-11. The residence time required for these halomethanes to equilibrate in the tubing (30 to 60 s) was determined experimentally. In a laboratory test, concentrations calculated from equilibrator measurements and based on published solubility values were found to differ by 6% to 16% from concentrations measured with a purge-and-trap apparatus, but uncertainties in the solubility values are likely to contribute significantly to the differences. In a comparison at sea, no significant difference was found between the semipermeable membrane equilibrator and another, more conventional equilibrator, except a 1.3% difference for CFC-11. This study demonstrates the feasibility of using semipermeable membranes in this and related applications.     

氯吡嘧磺隆和镉复合对斑马鱼肝脏的影响

为了探究污染物镉和氯吡嘧磺隆复合污染对非靶标生物斑马鱼的毒性作用,通过急性毒性试验,获得镉和氯吡嘧磺隆对斑马鱼的LC50.以LC25作为0水平,设置9个处理组进行试验,检测不同处理组斑马鱼96 h死亡率、斑马鱼肝脏中CAT、MDA和羧酸酯酶CarE.检测结果表明,镉和氯吡嘧磺隆对斑马鱼存在交互作用,当水体中镉浓度为3....     

氯乙烯储罐安全性分析

氯乙烯是被列入高毒物品的易燃易爆气体物质,液化氯乙烯由于其常温储存下蒸气压力高于大气压而在发生泄漏时容易引起火灾、爆炸、中毒等事故.氯乙烯储罐往往因为储存的物质量大而成为重大危险源.从国内现阶段法律法规、标准要求入手,分析了对氯乙烯储罐的安全要求,并以一具体储罐及其安全设施为实例,研究分析了储罐安全阀发生排放和储罐BLEVE等事故后果.并以此为基础,提出了本实例条件下保证储罐安全的具体要求.     

Degradation of MTBE and TBA by a new isolate from MTBE-contaminated soil

Methyl ten-butyl ether （MTBE）, a gasoline additive, possesses serious problems to the environmental health. In the present study, a bacterial culture named A-3 which could effectively degrade MTBE was isolated from the MTBE contaminated soil. The isolate was identified as Chryseobacterium sp., a new species capable of degrading MTBE. In order to enhance its degradation ability, selected environment factors were investigated. The results showed that the optimal temperature was in the range of 25-30℃, the pH was 7.0, the inoculum size was 2 × 10^8 CFU/ml and the optimal concentration of MTBE was from 50 to 100 mg/L. The maximum MTBE utilization rate （Vmax） was 102 nmol MTBE/（mg cell protein.h）. Furthermore, it was found that the isolate could also degrade tert-butyl alcohol （TBA）. The degradation rates of TBA were much faster than those of MTBE. The additional TBA would lead to the decrease of the initial MTBE degradation rate and the inhibitory effect of TBA increased with the increase of TBA concentration. Similar protein profiles at least seven peptides were demonstrated after SDS-PAGE analysis of crude extracts obtained from the cells growing in MTBE and TBA culture.     

Biodegradation of methyl parathion by Acinetobacter radioresistens USTB-04

Biodegradation of methyl parathion (MP),a widely used organophosphorus pesticide,was investigated using a newly isolated bacterium strain Acinetobacter radioresistens USTB-04.MP at an initial concentration of 1200 mg/L could be totally biodegraded by A.radioresistens USTB-04 as the sole carbon source less than 4 d in the presence of phosphate and urea as phosphorus and nitrogen sources,respectively.Biodegradation of MP was also achieved using cell-free extract of A.radioresistens USTB-04.MP at an initial concentration of 130 mg/L was completely biodegraded in 2 h in the presence of cell-free extract with a protein concentration of 148.0 mg/L,which was increased with the increase of pH from 5.0 to 8.0.Contrary to published reports,no intermediate or final degradation metabolites of MP could be observed.Thus we suggest that the cleavage of C--C bond on the benzene ring other than P-O bond may be the biodegradation pathway of MP by A.radioresistens USTB-04.     

用上流式生物反应器降解甲基叔丁基醚

用上流式生物反应器（UFBR）降解甲基叔丁基醚（MTBE）,研究了水力停留时间（HRT）和进水中MTBE质量浓度对MTBE去除率的影响。实验结果表明：在进水中MTBE质量浓度为25mg／L、HRT为18．6h的条件下,MTBE的去除率为84．13％;在HRT为18．6h、进水中MTBE质量浓度低于15mg／L的条件下,MTBE的去除率达92％以上。UFBR符合Eckenfelder动力学模型。