一种绿球藻的极端适应特性与虾青素高效诱导

绿球藻Chlorococcum sp.MC-1株系(简称MC-1)的高盐碱极端适应性和虾青素积累特性的初步研究结果显示,MC-1适应极端高碱培养并保持快速生长,NaHCO3浓度为8g.L-1时,Mc-1平均比生长率明显高于低碱培养(1g.L-1的NaHCO3),NaHCO3浓度为20g.L-1时平均比生长率与低碱培养的相近,其最高适应生长pH可达12以上。MC-1积累虾青素等次生类胡萝卜素与室内老化培养物的转红细胞相比,室外强光高盐高碱极端条件(室外太阳光、51g.L-1的NaCl、81g.L-1的NaHCO3)诱导转红细胞的虾青素和总类胡萝卜素含量分别提高了50.46%和71.20%,细胞转红速度显著加快,显示出极端条件对虾青素的高效诱导作用。     

液相色谱法测定鱼肌肉中孔雀石绿、结晶紫及其代谢物

孔雀石绿(MG)和结晶紫(GV)曾作为渔药使用,在鱼体内可分别代谢为无色孔雀石绿(LMG)及无色结晶紫(LGV),具有潜在的致癌性,已被许多国家禁用。本文研究了同时检测孔雀石绿、结晶紫及其代谢物无色孔雀石绿和无色结晶紫的液相色谱方法,建立了检测前处理方法及色谱条件。经过液液萃取和丙基磺酸阳离子树脂纯化,采用C18分离柱后串联二氧化铅柱氧化衍生的方法,同时检测母体药物及其代谢物,回收率>70%,重复性的相对标准偏差<15%,定量限分别为2μg/kg及1μg/kg。经样品实测,在一份鲈鱼样品中检测到无色孔雀石绿残留97μg/kg。     

Development of an online analyzer of atmospheric H2O2 and several organic hydroperoxides for field campaigns

An online automated instrument was developed for atmospheric measurements of hydroperoxides with separation and quantification of H₂O₂ and several organic hydroperoxides. Samples were trapped in aqueous solutions in a scrubbing glass coil. Analyses were performed on an HPLC column followed by para-hydroxyphenylacetic acid (POPHA) acetic acid and peroxidase derivatization and fluorescence detection. Analytical and sampling tests were performed on different parameters to obtain optimum signal-to-noise ratios, high resolution and collection efficiencies higher than 95% for H₂O₂ and organic hydroperoxides. The obtained performances show large improvements compared to previous studies. The sampling and analytical devices can be coupled providing an online analyzer. The device was used during two field campaigns in the Marseilles area in June 2001 (offline analyzer) and in July 2002 (online analyzer) at rural sites at low and high altitudes, respectively, during the ESCOMPTE and BOND campaigns. During the ESCOMPTE campaign, H₂O₂ was detected occasionally, and no organic hydroperoxides was observed. During the BOND campaign, substantial amounts of H₂O₂ and 1−HEHP+MHP were often detected, and two other organic hydroperoxides were occasionally detected. These observations are discussed.     

Analysis of fossil pigments from algae and bacteria in meromictic Lake Fidler, Tasmania, and its application to lake management

Lake Fidler is an ectogenic meromictic lake with a monimolimnion maintained by periodic incursions of brackish water from the lower Gordon River estuary. A dam across the middle reaches of the Gordon River has restricted these incursions of brackish water and meromictic stability has rapidly declined. A palaeolimnological study was carried in order to assess the historical development of meromixis and the impact of the dam on the microbiological communities in the lake. Fossil pigments in a 17 m sediment core were analysed using reverse phase high performance liquid chromatography (rp-HPLC) and mass spectrometry (MS). In addition, taphonomic studies of pigment production, deposition and degradation in the water column and surface sediments were used to identify planktonic and benthic pigment degradation processes and constrain the stratigraphic interpretation. Results comparing the pigment composition of pelagic sediment traps and littoral surface sediments indicated that the core from the centre of the lake would permit a historical reconstruction of planktonic bacterial and algal communities. Marked increases in prokaryotic pigments ca 3500 yr B.P. suggested the possible colonisation of a chemocline by phototrophic bacteria. Further changes in chlorophyll: carotenoid ratios and changes in relative abundances of both chlorophyll a and bacteriochlorophyll c derivatives also indicated that a change in the depositional environment had occurred; possibly due to altered stratification or anoxia. From this we infer the onset of either intermittent or permanent meromixis. Further increases in prokaryotic pigment abundance suggested that the present state of permanent meromixis was firmly established by 2070 ±50 ¹⁴C yr B.P., and diatom analysis confirmed the development of a stable mixolimnion. High resolution studies of the top 10 cm of sediments measured pigments in mean concentrations of 15.1 ng g^-1 with a mean S.D. of only 2.78 indicating little change in pigment abundance since the construction of the dam. Thus, Lake Fidler still retains most of the features of meromixis. However, evidence from nearby Lake Morrison and Sulphide Pool has shown that any further declines in meromictic stability will cause a rapid reversion to holomixis. Palaeolimnological evidence from the early stages of meromictic development of Lake Fidler suggests that such reversion to holomixis may not permanently eliminate all the microbiological communities, and that, given time, they may return and prosper with re-establishment of a suitable chemocline. These studies will guide recommendations for a management strategy to prevent the further decay of meromixis in the Gordon River lakes.     

Classification of marine diatoms using pigment ratio suites

Diatoms are widely distributed in many temperate areas and some species frequently form extensive blooms in spring. Hence, monitoring the variations of specific genera or species of diatoms is necessary for studying phytoplankton population dynamics in marine ecosystems. To test whether pigment ratios can be used to identify diatoms at a below-class taxonomic level, we analyzed 14 species/strains of diatoms isolated from Chinese seas using high performance liquid chromatography (HPLC). We normalized all pigment concentrations to total chlorophyll a to calculate the ratios of pigment to chlorophyll a, and calculated the ratios between accessory pigments (or pigment sums). Cluster analysis indicated that these diatoms could be classified into four clusters in terms of three accessory pigment ratios: chlorophyll c2: chlorophyll c1, fucoxanthin:total chlorophyll c and diadinoxanthin:diatoxanthin. The classification results matched well with those of biological taxonomy. To test the stability of the classification, pigment data from one species, cultured under different light intensities, and five new species/strains were calculated and used for discriminant analysis. The results show that the classification of diatom species using pigment ratio suites was stable for the variations of pigment ratios of species cultured in different light intensities. The introduction of new species, however, may confuse the classification within the current scheme. Classification of marine diatoms using pigment ratio suites is potentially valuable for the fine chemotaxonomy of phytoplankton at taxonomic levels below class and would advance studies on phytoplankton population dynamics and marine ecology.     

邻苯二甲醛柱前衍生高效液相色谱法测定马氏珠母贝中牛磺酸含量

应用邻苯二甲醛柱前衍生高效液相色谱法,测定了马氏珠母贝中牛磺酸,结果表明:采用邻苯二甲醛为柱前衍生剂,与原料中的牛磺酸发生衍生化反应后,以甲醇-乙酸钠溶液(体积比40︰60)为流动相,使用ODSC18分离柱,FLD检测器(EX=338nm,EM=444nm)等色谱条件下检测,牛磺酸的线性范围为2.0～14.0μg/mL,相关系数R2为0.9984,回收率为97.9%～103.0%,RSD=2.146%(n=6),检出限为0.77μg(S/N=3)。     

A Cloud Point Extraction Approach Developed for Analyzing Pesticides Prometryne and Isoproturon from Multi‐media

A new analytic methodology based on the cloud point extraction coupled with HPLC (CPE‐HPLC) was developed and successfully applied to determination of the pesticides isoproturon (IPU) and prometryne (PRO) from multi‐media (contaminated water, soil, and food vegetable). Several non‐ionic surfactants including poly ethylene glycol 6000 (PEG‐6000), TritonX‐114, and Triton X‐100 were comparatively analyzed as extraction solvents. Other parameters such as surfactant concentration, ionic strength, and equilibration temperature, and duration were also investigated. The optimal conditions for CPE were presented with 2.4% w/v PEG‐6000, 11% w/v Na₂SO₄ and heating assistance at 50°C for 25 min. The calibration curves for the two analytes were linear ranging from 0.001 to 10.0 mg L^?1, with correlation coefficients being 0.99 determined by a HPLC–UV detector. Under the condition, the average recoveries were 85.4–90.6% for water, 84.4–92.7% for soil, and 84.4–92.1% for vegetable. Thus, the method presented here was proved to be rapid, efficient, and green for extraction and determination of isoproturon and prometryne residues from food and multi‐environmental media.     

Distribution and source apportionment of Polycyclic aromatic hydrocarbons from atmospheric particulate matter PM<Subscript>2.5</Subscript> in Beijing

A total of 11 PM2.5 samples were collected from October 2003 to October 2004 at 8 sampling sites in Beijing city. The PM2.5 concentrations are all above the PM2.5 pollution standard （65 μg m^-3） established by Environmental Protection Agency, USA （USEPA） in 1997 except for the Ming Tombs site. PM2.5 concentrations in winter are much higher than in summer. The 16 Polycyclic aromatic hydrocarbons （PAHs） listed as priority pollutants by USEPA in PM2.5 were completely identified and quantified by high performance liquid chromatography （HPLC） with variable wavelength detector （VWD） and fluorescence detector （FLD） employed. The PM2.5 concentrations indicate that the pollution situation is still serious in Beijing. The sum of 16 PAHs concentrations ranged from 22.17 to 5366 ng m^-3. The concentrations of the heavier molecular weight PAHs have a different pollution trend from the lower PAHs. Seasonal variations were mainly attributed to the difference in coal combustion emission and meteorological conditions. The source apportionment analysis suggests that PAHs from PM2.5 in Beijing city mainly come from coal combustion and vehicle exhaust emission. New measures about restricting coal combustion and vehicle exhaust must be established as soon as possible to improve the air pollution situation in Beijing city.     

高效液相色谱中有效理论塔板数的变量因素和柱效率的研究

研究了高效液相色谱（ＨＰＬＣ）、高效离子色谱（ＨＰＩＣ）、高效离子排斥色谱（ＨＰＥＩＣ）和低压离子色谱（ＬＰＩＣ）中有效理论塔板数的变量因素，提出了能定量表述柱分离效率的参数──柱效率Ｓ及其计算方法。给出了其它色谱参数（分离度Ｒｓ，分离系数α和容量因子Ｋ＇）与有效理论塔板数及柱效率相关的实验结果。     

高压液相色谱法测定南极海洋冷水环境中的低分子挥发性脂肪酸

本文报道南极海洋冷水环境中的低分子挥发性脂肪酸的一种测定方法 ,阐述高压液相色谱法对海洋环境中 C1- C5年低分子挥发性脂肪酸的含量测定具有较好的适用性 ,说明该方法具有正确、灵敏、操作简单、快速及需要样品量少等特点。本方法的最低检测限在 0 .1 μg/ml以下 ,个别酸如丙烯酸可达 0 .0 0 1μg/ml以下。南极戴维斯站附近沿海 ,1 989年 1月 3日 6 0 m水柱体样品测定结果丙烯酸为 0 .0 0 4 - 0 .0 4 2 μg/ml,其他酸是 0 .1 - 1 .0 μg/ml,说明了该方法完全可满足实际海水样品的分析。