利用HPLC-ICP-MS方法测定中华绒螯蟹不同形态砷的残留量

采用高效液相色谱串联电感耦合等离子体质谱仪(HPLC-ICP-MS)测定中华绒螯蟹可食部位6种砷形态的残留量。经过前处理、提取和脱脂后,通过色谱柱、流动相、pH和流速等参数调节,筛选得到最优化的分离和检测条件。结果表明,6种砷形态的混合标准溶液在质量浓度0~50 μg/L范围时,均呈现良好的线性关系,其R²达到0.999,检测限为0.0060~0.0912 μg/kg,定量限为0.020~0.304 μg/kg。在样品中添加0.5、5、50 μg/L浓度水平,回收率良好,范围是70%~120%,相对标准偏差(RSD)均<5%,方法精密度与重复性均良好。本方法为中华绒螯蟹可食部位砷形态残留量建立了有效检测方法,为水产品砷残留快速检测提供技术支撑。     

Allochrony as a potential driver for reproductive isolation in adaptive radiations of European whitefish ecomorphs

In northern Fennoscandian lakes, monophylogenetic lineages of postglacial fishes are radiating into several adaptive forms, but the speciation process is still at an incipient stage. The speciation process has received increased attention over the years, but the underlying mechanisms and drivers are still debated and poorly understood. European whitefish (Coregonus lavaretus [L.]) is the most abundant fish species in these lakes and has evolved into several ecomorphs adapted to different trophic niches and habitats. Genetic divergence has been observed among these ecomorphs, but the mechanism(s) responsible for the ongoing build-up of reproductive isolation has still to be revealed. As these systems are young in evolutionary time (<10 kyr), prezygotic and postzygotic extrinsic isolation mechanisms are thought to be more likely to contribute to the reproductive isolation than intrinsic isolation mechanisms. We determined the gonadosomatic index (GSI) of three ecomorphs in two replicated lake systems and used GSI as a proxy to investigate the prezygotic isolation mechanism, allochrony, as a driving factor of divergence in this adaptive radiation of whitefish. We found that the three ecomorphs differed in GSI values within and between lakes, suggesting different spawning times of the ecomorphs. We also show that males of one ecomorph had equal onset of maturity as another ecomorph, giving novel insights into the ongoing gene flow observed between ecomorphs. The result supports allochrony as a driver for the divergence process of whitefish ecomorphs, but more evidence is still needed to rule out that the three ecomorphs make use of different spawning grounds.     

三峡库区沉积物中重金属化学形态分布特征与相关性分析

为全面了解三峡库区干支流沉积物中重金属的赋存形态,更好地为评价及保护三峡库区水生态环境提供科学依据,于2015年6月在三峡库区采集沉积物样品67个,通过ICP-MS等仪器测定了沉积物中各重金属元素的不同赋存形态量,运用SPSS、Matlab统计分析软件对重金属赋存形态进行对比分析。结果表明,库区表层沉积物中Cr、Ni元素主要以残渣态为主(占总量的75%以上);Cu、Zn、As元素主要以残渣态和可还原态为主(合计占总量80%~95%);Cd元素主要以酸可提取态和可还原态为主(分别占总量的55%和23%);Pb元素主要以可还原态和残渣态为主(各占总量的71%和18%)。Cd和Pb元素生物可利用态量较高,均超过该元素的长江沉积物背景值;该种形态下的重金属元素容易进入水体,并且在地球化学条件变化时转化成能被生物吸收和利用的形态,对生物造成较大危害。干流上游段重庆主城区及下游段,渠系河、大宁河、磨刀溪、沿渡河应当是重金属生态危害研究与防治的重点区域。     

坛紫菜中铝的形态分析及风险性评价

应用化学连续萃取法结合电感耦合等离子体质谱(ICP-MS)法对紫菜中铝的存在形态进行了初步研究,并对紫菜中铝食用安全性进行了评价。所测30份紫菜样品中铝的总含量范围为74.3~1 479 mg/kg,紫菜中铝的形态存在难溶态>有机态>无机态>水溶性游离态的分布规律。约75%的铝以难溶态存在。可溶态的铝主要以有机铝的形态存在,有机铝占总可溶态铝的72%左右。无机铝主要以Al(OH)₃的形态存在,水溶性游离态铝占无机铝的18.5%。通过模拟胃肠消化环境测定紫菜中铝的溶出率,结果表明,模拟胃液可溶出的铝占总铝的1.38%～6.80%,说明大部分铝在人体消化过程中不易溶出,对人体的潜在危害并不大。     

微波消解-原子荧光法测定竹丝鸡肉中的砷含量

采用微波消解-原子荧光法对广东竹丝鸡肉中有毒有害元素砷的含量进行抽样检测分析。结果表明:该方法检出限为0.067μg/L,回收率为95.7%~101.2%;竹丝鸡肉中砷的检出率为100%,平均残留量为0.041 mg/kg,符合我国无公害畜禽肉中砷的限量标准,并达到了我国绿色食品中砷限量标准。     

湄洲湾水域海水、沉积物中砷及重金属的含量分析

根据湄洲湾20个点位4批次水样，1次沉积物样，用原子荧光、原子吸收和多功能极谱仪测定海水和沉积物中砷及重金属的含量。采用单因子污染指数法和内梅罗综合污染指数法对湄洲湾水域海水和沉积物中的砷及重金属进行综合评价。结果表明，湄洲湾水域海水中的砷及重金属单因子污染指数Pi〈1，均符合第二类海水水质标准，内梅罗指数I〈1，总体...     

Reserarch advance on mechanism of arsenic trioxide on tumor

The article demonstrates the relative concepts of apoptosis and summarizes the effect of arsenic trioxide to the carcinoma, its possible principle included. Recent development of the reports about arsenic trioxide-induced apoptosis is referred and reviewed. Apoptosis is a natural mechanism and a common physiological death of cell, and its abnormity has great effect on cancer. Arsenic trioxide can induce apoptosis in APL cell and other cancer cells, and has been used in treating the patient with other kinds of malignant cancers. The mechanisms of arsenic trioxide-induced apoptosis are gradually becoming a hotspot, but still not lucid. With intensive study of arsenic trioxide, it can be a useful ways in treating cancer patients in the future.     

不同色泽石粉的质量分析评估

为了在饲料生产中更安全、科学地使用石粉,试验检测了河南省南阳地区不同色泽的石粉中钙、镁、铅、氟和砷等几种金属的含量,结果表明:白石粉中钙含量最高,红石粉中镁含量最高,灰石粉中铅含量超标。由于南阳石粉不论其色泽如何价格均相同,所以白石粉的性价比更高,更适合用作饲料原料来获得更高的经济效益。     

毛头鬼伞子实体对重金属元素的富集特性

通过对毛头鬼伞(Coprinus comatus)产区中原辅材料中铅(Hg)、镉(Cd)、砷(As)、汞(Pb)4种重金属含量的检测和使用添加不同浓度重金属栽培材料的栽培试验,分析栽培原辅料中重金属含量对子实体中重金属含量的影响,为毛头鬼伞的安全生产提供参考。试验结果表明,除水之外的13个测试原辅材料样品中均含一定量的重金属元素;子实体中的重金属含量随着栽培材料中重金属元素含量的增加而呈上升趋势,子实体对覆土和对栽培基质中4种重金属元素的富集强弱分别为Hg>Cd>As>Pb和Hg>Cd>Pb>As,其中对覆土和栽培基质中重金属汞分别表现较弱和一定的富集作用。     

森林土壤有机氮的X光吸收近边结构光谱技术测定

本研究通过采用氮的K边X光吸收近边结构(XANES)技术来了解森林土壤有机氮,以此深入研究土壤中有机氮种类与其转化的定量关系。土壤样品采自台湾中部的云杉、铁杉林与草地。结果表明,氮的 XANES 可以揭示样品中不同的氮的种类。在土壤腐植质、可溶性氮及本体土壤中胺态及吡咯氮占了主要的比率。然而不同处理及植被下的土壤样品氮的种类分布是不同的。云杉与铁杉土壤可溶性有机氮在402.3 eV 能量处有显著的差异。在A层土壤中,吡啶类氮含量要显著高于O层土壤,说明氮在不同土层中的转化率存在极大的差异,这种变化对于氮在森林土壤中的循环将起重要作用。图3表1参8。