使用超高效液相色谱ACQUITY UPLC快速分析醛酮类化合物

醛酮类化合物是焚烧过程扩散到环境中的产物,这些化合物大部分都是已知的致癌物.因此,美国EPA和一些州开发了分析这些化合物的方法,包括US EPA TO5 (空气),方法554 (饮用水),方法8315 A选项1和2 (废水、土壤和空气),以及加利福尼亚州方法1004 (羰基化合物,机动车排放尾气中的醇类氧化物).这些方法使用二硝基苯肼(DNPH)衍生化这些化合物,然后用HPLC分离并紫外检测(吸收波长360nm),目标分析物因方法的不同而略有不同.当前使用的方法运行时间超过40min以上,需要设置多种色谱柱方可达到可接受的化合物分离度.     

Heavy Metals in Epiphytic Mosses: An Experience in Florence

The epiphytic moss Hypnum cupressiforme has been used for passive monitoring of airborne heavy metals pollution by vehicular traffic in the urban area of Florence. Lead, cadmium, zinc and copper were determined by differential pulse anodic stripping voltammetry (DPASV). in the summer of 1993 about 30 samples were collected from the trunks of holm oak at the same height (1 metre) from the soil. Lead contents fall within the range of 0.02-1.08 μ moles g^-1 (dry weight) and for this metal, the emission source may be attributed mainly to vehicular traffic in poorly industrialized urban areas. Some evaluations have been carried out about the employment of Zn/Pb molar ratio for characterizing airborne pollution in urban areas.     

Pigeon homing: a comparison between groups raised under different conditions

Summary The homing ability of a group of pigeons raised under conditions of continuous exposure to windborne information was compared to that of another group subjected to exposure to winds only during the time spent in pre-test training flights. The results of release experiments at sites that were unfamiliar to the pigeons show that both bird groups, which had been made temporarily anosmic, had impaired initial homeward orientation and homing ability. These results, which do not entirely concur with the recent findings of Wiltschko and his coworkers, show that the raising and training procedures we used do not influence the nature of the cues used in pigeon homing. If the exposure of birds to wind-borne information is reduced, this does not bring into play any effective non-olfactory mechanisms of navigation; it simply hinders the development of the olfactory map and impairs the homing ability. Offprint requests to: S. Benvenuti     

Metal contamination in urban street sediment in Pisa (Italy) can affect the production of antioxidant metabolites in Taraxacum officinale Weber

Taraxacum officinale Weber (dandelion) is a very ubiquitous species, and it can grow in urban environments on metal-polluted sediments deposited in the gutters. This study represents a preliminary step to verify the presence of metals in sediments collected in urban streets in Pisa and to assess the alteration in dandelion metabolites in order to understand its adaptation to polluted environments. The soil and sediments were collected at three urban streets and analyzed for total and extractable Cr, Pb, Cu, Ni, and Zn. The total values of Pb and Zn in street sediments exceeded the limits for residential areas of soils. Zn was the most mobile of the metals analyzed. Floating cultivations trials were set up with dandelion seedlings and street sediments. The metals were analyzed in roots and leaves. Antioxidant power, anthocyanins, polyphenols, non-protein thiols (NP-TH) and chlorophylls were measured in dandelion leaves. The first two parameters (anthocyanins and antioxidant power) were higher in the polluted samples compared to the control; chlorophyll content was lower in the treated samples, whereas NP-TH showed no differences. NP-TH groups determined in roots were associated with the root content of Zn and Pb. These results indicate that dandelion can tolerate plant stress by altering its metabolite content.     

Geographical and temporal variability in pigeon homing

Summary Young homing pigeons from the same German stocks were housed in two lofts, one in southern Germany, near Munich, and one in Italy, near Pisa. In the course of 1 year, two synchronized releases at sites 22–25 km NNW and SSE from each of the lofts were conducted every month. The pigeons that returned were released a second time at a site about 75 km east of home.Both initial homeward orientation and homing success were considerably better in Italy than in Germany. Annual cycles, with maxima in summer and minima in winter, were observed in both countries. They were most pronounced in initial orientation in Italy and in homing performance in Germany. Correlations between homing parameters and ambient temperature correspond to the annual cycles, but they do not indicate that the geographical and seasonal differences in homing behaviour are directly caused by actual temperature at the time of release.Our findings (together with earlier ones) suggest that environmental conditions may be variably conducive to the homeward orientation of pigeons according to spatial and temporal variations in the climate.     

超高效液相色谱(ACQUITY UPLC)应用于环境水中多环芳烃(PAHs)和爆炸物分析

多环芳烃（PAHs）和爆炸物残留是广泛存在于环境中的污染物．前者是很多工业过程的副产物,后者则在军事活动中产生．分析PAHs和爆炸残留物的标准和官方方法仅应用于水、空气、固体废物以及食品分析．这些方法使用HPLC,其运行时间超过30min以上．沃特世超高效液相色谱（ACQUITY UPLC）系统相同的分析可以在低于10min的时间内完成,运行时间减少60％以上．     

Do activity costs determine foraging tactics for an arctic seabird?

How energy costs affect foraging decisions is poorly understood for marine animals. To provide data relevant to this topic, we examined the relationship between activity levels and foraging behavior by attaching activity recorders to 29 chick-rearing wing-propelled diving birds (thick-billed murres, Uria lomvia) in 1999–2000. We connected the activity during the final dive bout with the prey item we observed being fed to the chicks. After accounting for changes in activity level with depth, activity was highest during the final dive of a dive bout, reflecting maneuvring during prey capture. Pelagic prey items, especially invertebrates (amphipods), were associated with higher depth-corrected activity, leading to shorter dives for a given depth (presumably due to higher oxygen consumption rates) and, thus, shorter search times (lower bottom time for a given depth). Pelagic prey items were likely captured during active pursuit, with the birds actively seeking and pursuing schooling mid-water prey. In contrast, benthic prey involved low activity and extended search times, suggesting that the birds slowly glided along the bottom in search for prey hidden in the sediments or rocks. We concluded that activity levels are important in determining the foraging tactics of marine predators. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.