气相色谱-串联质谱法测定沉积物中多环芳烃

采用ASE法提取沉积物中16种多环芳烃,以固相萃取法净化提取液,用气相色谱-串联质谱法测定。通过优化测定条件,使方法在5.00μg/L~1 600μg/L范围内线性良好,方法检出限为0.15μg/kg~0.66μg/kg。空白石英砂的加标回收率为61.9%~121%,7次测定结果的RSD为2.6%~11.1%。     

Experimental research of LNG accidental underwater release and combustion behavior

Evaluating potential hazards caused by accidental LNG release from underwater pipelines or vessels is a significant consideration in marine transportation safety. The aim of this study was to capture the dynamic behavior of LNG jet released under water and to analyze its vapor dispersion characteristics and combustion characteristics on the water surface during different release scenarios. Controlled experiments were conducted where LNG was jet released from a cryogenic storage tank. The dynamic process of LNG being jet released from orifices of different sizes and shapes, as well as the rising plume structure, were captured by a high-speed camera. The leakage flow rate and pipeline pressure were recorded by a flow meter and pressure gauge, respectively. The concentration distribution that emanated from the water surface was measured utilizing methane sensors in different positions with various wind speeds. The flame combustion characteristics of LNG vapor clouds, which immediately ignited upon the enclosed water tank, were also recorded. Additionally, the mass burning rate of the flame on the water surface was evaluated, and a new correlation between the ratio of flame length and width was established. The results indicated a large dimensionless heat release rate (Q*) and a continuous release flow rate in a limited burning area. This study could provide greater understanding of the mechanisms of LNG release and combustion behavior under water.     

高效液相色谱-三重四级杆/复合线性离子阱质谱法测定饮用水中22种邻苯二甲酸酯

建立了一种同时测定饮用水中22种邻苯二甲酸酯(PAEs)的高效液相色谱-三重四级杆/复合线性离子阱质谱方法:饮用水样品经针头过滤器过滤,选用Biphenyl液相色谱柱进行分离,以含0.1%甲酸的水溶液和含0.1%甲酸的甲醇溶液为流动相,电离模式为电喷雾正离子,选用多反应监测触发增强子离子扫描模式进行检测。结果表明,22种PAEs的灵敏度良好,定量限为0.001～0.1 μg/L。配制浓度为0.1～100.0 μg/L的混标溶液进行进样分析,分析结果显示,22种PAEs在该范围内的线性关系良好,相关系数均大于0.995,方法的平均回收率为82.9%～108.9%,相对标准偏差为0.9%～11.2%。同时,使用增强子离子扫描谱图进行搜库匹配,定性准确性高。该方法适用于饮用水中PAEs的检测。     

An LC-MS/MS method for creatine and creatinine analysis in paraquat-intoxicated patients

Abstract

A sudden increase in serum creatinine after paraquat intoxication has been reported in several clinical studies. However, this dramatic change of creatinine may be possibly due to an interconversion of creatine-creatinine in relation to paraquat toxicity. In order to investigate the creatine-creatinine relationship, a liquid chromatography tandem mass spectrometry in combination with electrospray ionization was developed and validated for simultaneous determination of creatine and creatinine in the serum. The chromatographic separation was achieved on a Gemini® C₆-Phenyl column with a gradient elution consisting of 0.1% formic acid in ultrapure water and methanol as the mobile phase. The method yielded suitable levels of specificity and selectivity, and calibration curves of creatine and creatinine in serum were linear over the concentration range of 0.5–200?µg mL^?1. The limit of quantification of both compounds was 0.5?µg mL^?1, and the method was accurate within the recovery range of 96.23–102.75%, indicating the robustness of the method. The method was successfully applied to toxicological samples from paraquat-intoxicated patients, and the concentrations of creatine and creatinine were quantified. High creatine concentrations in serum samples were observed which may lead to high serum creatinine despite normal kidney function as creatine is converted to creatinine in proportion to its concentration.     

改进测定水中氨氮分子吸收光谱法的试验研究

水中氨氮含量是反应水质状况的重要指标。文章对测定水中氨氮气相分子吸收光谱法(标准号HJ/T195-2005)进行了改进试验研究。第一,对氧化剂的配比进行了改进,使氨氮的测定范围扩展至100μg。第二,对标准HJ/T195-2005中直接使用亚硝酸钠标准溶液做标准曲线的处理方式也做了探讨。通过一系列对比实验认为,应用硫酸铵标准溶液做工作曲线更加准确合理。最后应用改进后的气相分子吸收光谱法和纳氏比色法或滴定法对多种实际废水样品进行同时测定。结果表明,改进后的气相分子吸收光谱法测定氨氮的范围更宽,灵敏度更高和准确度更好。     

Releases of phosphate fertilizer industry in the surrounding environment: Investigation on heavy metals and polonium-210 in soil

Distribution of Cu,Zn,Pb,Cr,Ni,Mn concentrations and the activity of polonium-210 in the surrounding area of a phosphate fertilizer industry located on the eastern coast of the Mediterranean Sea has been determined.Nineteen sampling sites were distributed around the industrial zone on a surface area of about 100,000 m2.Atomic absorption spectroscopy and Alpha spectroscopy were used to quantify the heavy elements and polonium-210,respectively.Investigation on a particle scale was conducted by TEM and SEM coupled to EDX and X-ray cartography to determine the nature of heavy elements carriers and their distribution.Heavy elements were mainly concentrated inside the particle size fraction 50 μm.Their levels decreased with distance increasing from the industry.According to the reference soil,enrichment factors were about 10,15,32 and 100 times for Zn,Pb,Cu,and Cr,respectively inside the particle size fraction 50 μm on the closest sites to the industry.The main contaminant sources were transport and storage of row materials and the free release of phosphogypsum waste.Heavy elements were entrapped inside agglomerates of sulfates,phosphates and iron oxihydroxides in a di used shape.Polonium-210 with an enrichment factor of about 56,showed the same behavior of the spatial distribution of the trace elements.     

微囊藻毒素分离及鉴定

微囊藻毒素是一类由蓝藻产生的具有肝毒性的生物毒素。微囊藻毒素标准品是开展为微囊藻毒素相关研究的必需的实验材料,文章以滇池天然水华蓝藻为原料,建立了以5%乙酸和75%的甲醇溶液提取,通过优化提取、分离和制备条件,制备了一定量的微囊藻毒素高纯度样品,经HPLC鉴定分析,纯度可达90%以上。文章在相同的质谱条件下分别对MC-LR和[Dha7]MC-LR等毒素进行了质谱检测,一级质谱结果表明,MC-LR和[Dha7]MC-LR的一价电离离子峰分别为995和981,MC-RR的二价电离离子峰为520,并分析它们的二级质谱裂解特征,确定三种毒素化学结构MC-RR为环(Ala-Arg-MeAsp-Arg-Adda-Glu-Mdha)、MC-LR为环(Ala-Leu-MeAsp-Arg-Adda-Glu-Mdha)、[Dha7]MC-LR为环(Ala-Leu-MeAsp-Arg-Adda-Glu-Dha)。改良后的检测方法同样应用于检测受微囊藻毒素污染的武汉东湖水样。     

火焰原子吸收法测定苹果中波尔多液的农药残留

通过原子吸收法测定苹果果皮、果肉上波尔多液的农药残留铜的含量,结果表明:喷洒了波尔多液的苹果果皮上铜含量明显大于果肉,在果皮上有一定的农药残留;而未喷洒波尔多液的苹果果皮和果肉中铜的含量的差异很小。     

Nutritional benefits of filial cannibalism in three-spined sticklebacks (<Emphasis Type="Italic">Gasterosteus aculeatus</Emphasis>)

Although filial cannibalism (eating one’s own offspring) occurs in numerous species, including several teleost fishes, its adaptive value is still not well understood. One often-discussed explanation is that individuals enhance their mass and body condition by consuming part of their eggs. However, evidence for this assumption is scarce thus far. In this study, male three-spined sticklebacks (Gasterosteus aculeatus), a species with paternal care, were allowed to care for a batch of eggs or for an empty nest under food-deprived conditions. All brood-caring males cannibalised at least part of their eggs and thus preserved their initial mass and body condition. Furthermore, mass as well as body condition was significant positively correlated with the number of cannibalised eggs. In contrast, empty-nest males that had no possibility to cannibalise eggs significantly lost mass and body condition. This is, to our knowledge, the first experimentally documented evidence that mass as well as body condition were preserved by filial cannibalism.     

SPME-GC/MS法测定垃圾渗沥液中双酚A

建立了固相微萃取-气相色谱质谱联用法测定垃圾渗沥液中双酚A的方法,并用于广州大田山垃圾渗沥液中双酚A含量的测定。对影响萃取的参数进行了优化,实验选用涂层厚度为85μm聚丙烯酸酯(PA)萃取纤维,在搅拌速度为1200r/min、NaCl浓度为20%、pH2.0和室温条件下萃取60min。方法的线性范围为0.1～100μg/L,检出限为0.03μg/L,精密度为6.6%。应用本方法监测了广州大田山垃圾渗沥液中BPA的含量在生物法处理过程中的变化情况。