液相色谱-串联质谱法快速测定水产品中结晶紫及其隐色代谢物残留

采用液相色谱-串联质谱法(LC-MS/MS)测定了水产品中结晶紫以及它的隐色代谢物残留。匀质后的水产品样品用乙腈和乙酸铵缓冲液提取,合并提取液,用二氯甲烷反提取,经中性氧化铝柱和PRS柱固相萃取净化,且不使用氧化铅柱在线氧化,色谱分离后直接进入串联质谱检测器。采用电喷雾正离子,多反应监测(MRM)模式检测。方法的检出限可达0.5 ng/g,线性方程的相关系数r大于0.99,添加样品平均回收率为77.6%~93.8%,相对标准偏差均小于8.2%。     

Modeling a swimming fish with an initial boundary value problem: Unsteady maneuvers of an elastic plate with internal force generation

In order to model unsteady maneuvers in swimming fish, we develop an initial-boundary value problem for a fourth-order hyperbolic partial differential equation in which the fish's body is treated as an inhomogeneous elastic plate. The model is derived from the three-dimensional equations of elastic dynamics, and is essentially a simple variant of the classical Kirchhoff model for a dynamic plate. The model incorporates body forces generating moment to simulate muscle force generation in fish. The initial-boundary value problem is reduced to a beam model in one spatial dimension and formulated computationally using finite differences. Interaction with the surrounding water is represented by nonlinear viscous damping. Two example applications using simple but physically reasonable physiological parameters are presented and interpreted. One models the acceleration from rest to steady swimming, the other a rapid turn from rest.     

Determination of chloramphenicol in aquatic products by graphene‐based SPE coupled with HPLC‐MS/MS

An effective analytical protocol using graphene‐based SPE coupled with HPLC‐MS/MS for determination of chloramphenicol (CAP) in aquatic products has been developed. In the present work, graphene was evaluated as SPE sorbents for the analytes enrichment and clean up. The target analytes were quantified by a triple‐quadrupole linear ion trap MS in multiple‐reaction monitoring mode. In addition, the proposed method was validated according to Commission Decision 2002/657/EC. The calibration curve was linear over the range of 0.5–100 ng/mL. The mean values of RSD of intra‐ and interday ranging from 1.48 to 4.29% and from 3.25 to 7.42% were obtained, respectively. In the three fortified levels, the recoveries of CAP ranging from 92.3 to 103.4% with RSDs ≤ 5.58% were obtained. The proposed method has been successfully applied to the analysis of CAP in several aquatic product samples, indicating that graphene was a potential SPE sorbent for the enrichment of trace residues in food samples.     

MP-AES法测定水产饲料中多种金属元素

应用微波等离子体发射光谱(microwave plasma-atomic emission spectrometry, MP-AES)技术, 建立水产饲料中铜、铁、锰、锌、钾、钠等元素MP-AES分析方法。样品采用干灰化法消解, 开展了方法学研究试验, 同时与AAS和ICP-AES方法进行比对, 并完成FAPAS能力验证样品和标准物质确证试验。通过优化MP-AES仪器的各项参数, 在所选定的条件下, 各元素的线性相关系数在0.999以上, 检出限在0.4～3.9 mg·kg-1之间, 加标回收率在103%～112%之间, 精密度试验相对标准偏差在0.2%～0.6%之间;测定结果与AAS法、ICP-AES法比对, 单因素方差分析(α=0.05)各元素P值在0.065～0.438之间, 均大于0.05, 无显著性差异;FAPAS奶牛饲料能力验证和灌木枝叶(GBW07602)标准物质确证试验的各元素测定值均在参考值范围内。结果表明, 所建立的方法简单、快速, 线性范围宽, 具有良好的准确性和精密度;MP-AES无需使用乙炔、氩气, 安全、经济、环保, 能降低检测成本、提高检测效率, 可替代AAS、ICP-AES法测定水产饲料中的六种金属元素, 为水产饲料的质量控制提供理想的元素分析方法。     

In situ application of a cellulose bag and an ion exchanger for differentiation of labile and inert metal species in aquatic systems

This work involved the development and application of a new analytical procedure for in-situ characterization of the lability of metal species in aquatic systems by using a system equipped with a diffusion membrane and cellulose organomodified with p-aminobenzoic acid groups (DM-Cell-PAB). To this end, the DM-Cell-PAB system was prepared by adding cellulose organomodified with p-aminobenzoic acid groups (Cell-PAB) to pre-purified cellulose bags. After the DM-Cell-PAB system was sealed, it was examined in the laboratory. The in-situ application involved immersing the DM-Cell-PAB system in two different rivers, enabling us to study the relative lability of metal species (Cu, Cd, Fe, Mn, and Ni) as a function of time and quantity of exchanger. The procedure is simple and opens up a new perspective for understanding environmental phenomena relating to the complexation, transport, stability, and lability of metal species in aquatic systems rich in organic matter.     

高效液相色谱法测定水产品中喹乙醇的残留量

建立了水产品中喹乙醇残留量的测定方法。主要研究了样品的预处理方法,提出了以水为提取剂,以硼砂一硫酸锌为高效蛋白去除剂的样品处理方法。该方法灵敏、准确,适合于水产品中微量喹乙醇残留量的测定。方法的检出限为40μg／kg。     

塞曼石墨炉原子吸收法测定水产品中的铬

研究了石墨炉原子吸收法测定的方法 ,对多种方法比较研究得出 ,样品经过干法灰化 ,以硝酸溶解未消解完全的样品 ,用硝酸镁作基体改进剂 ,利用塞曼扣背景技术 ,热解平台石墨管进行测定 ,线性范围为2 .5— 5 0 μg·L-1,回收率为 90 %— 10 3% ,相对标准偏差为 6 .8%。     

Analysis of emerging and related pollutants in aquatic biota

Water bodies cover approximately 70 % of the earth´s surface, making them ecosystems with a high environmental value and the habitat for numerous species of flora and fauna. Emerging pollutants (EPs) are ubiquitous anthropogenic compounds of environmental concern that can be found at different concentration levels in matrices such as sediment, water and aquatic biota. In addition, EPs can be bioaccumulated and biomagnified, inducing adverse effects on biota, and posing a risk to humans when contaminated biota is consumed. Unlike abiotic matrices, the occurrence of EPs in aquatic biota has not been widely studied. This is probably because their complexity, due to the presence of lipids, proteins and other organic compounds, makes the extraction and analysis of EPs difficult. This review gathers the most relevant analytical methods published between 2014 and 2019, comparing them and evaluating their strengths and weaknesses. It is intended to provide a better understanding of the development of new and improved methods, and to be a reference for researchers who are looking for the best methodology for their studies.     

An Application of Capillary Electrophoresis for the Analysis of Algal Toxins from the Aquatic Environment

In this work capillary electrophoresis (CE) with UV detection has been applied to the analysis of different natural toxins produced in the aquatic environment. This technique is presented as an alternative to other chemical techniques such as HPLC, and the optimisation of analytical methodologies was carried out for diverse marine toxins including Paralytic and Amnesic and some polyether toxins, such as Yessotoxins, as well as for certain microcystin toxins produced by cyanobacteria present in freshwaters. Sample preparation steps were optimised and adequate electrophoretic conditions developed for achieving a complete separation of compounds with similar structures involved in such contamination. The influence of the biological matrices where they are involved has also been studied and the potential use of CE-UV as a tool for monitoring these aquatic toxins is also discussed.     

固相萃取-抑制电导离子色谱法测定水产品中有机酸

建立了梯度淋洗-抑制型电导离子色谱法检测水产品中有机酸的方法。在2～3个数量级范围内,该方法对目标化合物的检测线性良好。酒石酸的线性范围为15～500 ng/mL,检测限为0.05 mg/kg;柠檬酸线性范围为8～500 ng/mL,检测限为0.03 mg/kg。以大黄鱼、中华绒螯蟹、南美白对虾、文蛤为空白样品,加入酒石酸和柠檬酸质量分数分别为0.05,0.07和0.10 mg/kg,酒石酸的加标回收率介于84.4%～89.2%,RSD<6.5%,柠檬酸的加标回收率介于87.5%～93.8%,RSD<5.9%。