Polychlorinated biphenyls in two mollusc species from the coast of Tenerife (Canary Islands, Spain)

Levels of PCBs were determined in two marine organisms, limpets (Patella ullisiponensis aspera) and winkles (Ossilinus atratus), sampled in three stations in the south east coast of Tenerife during 1993. Winkles and limpets exhibited different PCB patterns. Principal Component Analysis (PCA) was used to study the patterns and the relationships among PCBs.     

The conversion of chicken manure to biooil by fast pyrolysis II. Analysis of chicken manure,biooils, and char by curie-point pyrolysis-gas chromatography/mass spectrometry (Cp Py-GC/MS)

The initial chicken manure and the three fractions derived from it by fast pyrolysis, that is, the two biooils Fractions I and II as well as the residual char were analyzed by Curie-point pyrolysis-gas chromatography/mass spectrometry (Cp Py-GC/MS). The individual compounds identified were grouped into the following six compound classes: (a) N-heterocyclics; (b) substituted furans; (c) phenol and substituted phenols; (d) benzene and substituted benzenes; (e) carbocyclics; and (f) aliphatics. Of special interest were the relatively high concentrations of N-heterocyclics in biooil Fraction II which was obtained in the highest yield and had the highest calorific value. Prominent N-heterocyclics in biooil Fraction II were methyl-and ethyl-substituted pyrroles, pyridines, pyrimidine, pyrazines, and pteridine. Also noteworthy was the high abundance of aliphatics in biooil Fraction I and the char. The alkanes and alkenes in biooil Fraction I ranged from n-C₇ to n-C₁₈ and C_7:1 to C_18:1, respectively, and those in the char from n-C₇ to n-C₁₉ and C_7:1 to C_19:1, respectively. The N-heterocyclics in the two biooil Fractions came from the chicken manure, from proteinaceous materials during fast pyrolysis or were formed during the fast pyrolysis manure conversion by the Maillard reaction which involved the formation of N-heterocyclics by amino acids interacting with sugars.     

Behavior of fenhexamid in soil and water

A study was conducted to investigate fenhexamid (FEX) behavior in soil and in water. FEX proved to be rather stable at acid pH but showed slight degradation at neutral and alkaline pH. After 101 days of FEX spiking of a soil sample, 94% at pH 4, 12% at pH 7 and 23% at pH 9 of the active ingredient was still present. In natural water the rate of FEX disappearance appeared to be slow which may be due to abiotic rather than biotic processes. The soil degradation tests showed low persistence of the active ingredient if a good microflora activity is guaranteed (DT₅₀ about 1 day). Moreover, in absence of microorganisms, FEX proved to be stable. Humidities of 25 and 50% of Water Holding Capacity (WHC) influenced in equal measure the rate of degradation. From the same soil, a bacterium was isolated and identified as Bacillus megaterium, which was able to metabolize FEX with the hydroxylation of the cyclohexane ring. Moreover, FEX showed an elevated affinity for humic acid (73%), smectite (31%), and ferrihydrite(20%) and low affinity for vermiculite (11%) and kaolinite (7%).     

The Use of the Isotopic Composition of Individual Compounds for Correlating Spilled Oils and Refined Products in the Environment with Suspected Sources

Correlation of crude oils, or refined products, in the environment with suspected sources is typically undertaken through the use of GC and GCMS and in certain cases bulk carbon isotope compositions. However, with crude condensates, or refined products in particular, the absence, or low concentration, of biomarkers precludes their successful use for making unique correlations. An alternative and, sometimes, complimentary technique for correlation of such products is evolving through the use of combined gas chromatography-isotope ratio mass spectrometry (GCIRMS). This approach permits determination of the carbon and hydrogen isotopic composition of individual compounds in the crude oil or refined product to produce isotopic fingerprints for use in correlation studies. In this paper, it is proposed to review applications of GCIRMS to the correlation of various spilled products with their suspected sources in different environments. Whilst not proposing that this technique will replace GC or GCMS; it is proposed that GCIRMS is a very powerful tool to be used in conjunction with GC and GCMS to make such correlations. Although isotopic fractionation has been observed in some of the lighter components such as benzene and toluene, higher carbon numbered compounds, say above C 10 , do not appear to undergo any significant isotopic fractionation as a result of weathering. Furthermore with refined products, isotopic fractionation of the lighter components has the potential to demonstrate the onset of natural attenuation of refined products in the environment.     

气相色谱法测定水体中多氯联苯Aroclor系列

采用液液萃取—气相色谱法(GC-ECD)测定水体中多氯联苯Aroclor系列Aroclor1016、Aroclor1221、Aroclor1232、Aroclor1242、Aroclor1248、Aroclor1254、Aroclor1260。样品经正己烷溶剂萃取,再经全自动样品浓缩仪(EVA)浓缩萃取液至1 mL,供气相色谱仪测定,外标法定量,加标回收率在75%~110%之间,检出限为0.1μg/L。该方法采用双塔双柱双检测器,排除了误检和其他物质的干扰,保证了分析结果的可靠性,方法简单、灵敏、准确。     

气相色谱／质量选择检测器测定死鱼水体中有机污染物

为查明有机污染物的种类,取死鱼水经GDX-501树脂富集后,用气相色谱/质量选择检测器分析。检出水中82种污染物。     

超高效液相色谱三重四极杆质谱联用法测定水中的苯胺及联苯胺

将含有苯胺及联苯胺的水样过滤后加入乙腈(水样中乙腈比例为20%)直接进样,使用超高效液相色谱三重四极杆质谱联用法测定。通过选择离子反应监测,可实现定性和外标法定量分析。该法测定生活饮用水及其水源水中苯胺和联苯胺的最低检测浓度分别为2和0.2ng/mL,对实际样品的加标回收率为苯胺:112%～115%,联苯胺:84.5%～86.5%,该方法绿色环保、简单、具有较高的灵敏度和较低的检出限。     

离子色谱法在环境分析中的应用

对离子色谱法在环境分析中的应用、优缺点进行了综述,并对其在环境分析中的发展前景作了评估。     

大气中氯氟烃类物质浓度变化的研究

通过低温脱水和低温浓缩,建立了用气相色谱测定大气中超痕量氯氟烃类物质的分析。方法,对上海市清洁大气中ＣＦＣｓ本底浓度进行了监测,并与日本东京大学的数据进行了比较。     

用TBP萃取色层法从废物中提取高纯氧化钪工艺研究

依据Ｐ２０４回收粗氧化钪含杂质特点，研究了ＴＢＰ萃取色层提纯工艺，工业生产实践结果表明，投入含量为７５％－９９．９％的粗氧化钪，经ＴＢＰ色层提纯后获得纯度为９９．９９９９％的高纯氧化钪，收率〉９４．４５％，成本为３１００元／ｋｇ。