Influence of carrier solution ionic strength and injected sample load on retention and recovery of natural nanoparticles using Flow Field-Flow Fractionation
Influence of carrier solution ionic strength and injected sample load on retention and recovery of natural nanoparticles using Flow Field-Flow Fractionation
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DOI：
10.1016/j.chroma.2011.07.010
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发表时间：
2011-09-23
影响因子：
4.1
通讯作者：
Hofmann, T.
中科院分区：
文献类型：
--
作者：
Neubauer, E.;v.d. Kammer, F.;Hofmann, T.
天然纳米颗粒，包括天然有机物（NOM）和无机矿物类相，已被广泛使用流场流分级（FlowFFF）的特点。通常使用聚苯乙烯磺酸盐（PSS）标准品进行校准，以确定NOM的分子量分布，然而，如果分析的样品与PSS标准品相比具有不同的电荷密度，则所得分子量分布可能变得无意义。因此，本研究调查和比较的离子强度和样品负载的保留时间和回收率的PSS标准和天然纳米粒子从各种来源的影响。载体溶液中的最小离子强度和令人满意的分离所需的最大进样量取决于PSS标准品的分子量和NOM的性质。结果取决于FlowFFF内的条件和参数的程度在不同的天然纳米颗粒样品之间显着变化。我们发现，可能需要在与实际样品运行不同的条件下校准通道。在良好控制和记录的条件下，这可能是偏离“标准品和样品条件相同”模式的重要一步。从测试的所有条件中，在载体溶液中升高的离子强度（> 0.04M）和低注射质量的PSS下获得最可靠的分子量校准。然而，即使在这些优化的条件下，在计算的分子量中发生高达20%的变化，并且NOM的回收率在高离子强度下福尔斯高达50%。许多应用的目标是正确的分子量分布和测量低浓度的元素结合到天然纳米粒子。然而，我们的结论是，找到同样适合这两个分析任务的条件并不总是可行的。(C)2011爱思唯尔有限公司版权所有。
Natural nanoparticles, including both natural organic matter (NOM) and inorganic mineral-like phases, have been broadly characterized using Flow Field-Flow Fractionation (FlowFFF). Calibration with polystyrene sulfonate (PSS) standards was generally carried out in order to determine the molecular weight distribution of the NOM, however if the analyzed sample has a different charge density compared to the PSS standards, the resulting molecular weight distribution may become meaningless. The presented study therefore investigates and compares the influences of ionic strength and sample load on the retention time and recovery of both PSS standards and natural nanoparticles from a variety of sources. The minimum ionic strength in the carrier solution and the maximum injected sample load required for satisfactory separation depend on the molecular weight of the PSS standards and on the nature of the NOM. The degree to which results depend on conditions and parameters within the FlowFFF varies significantly between the different natural nanoparticle samples. We found that it may be necessary to calibrate the channel under different conditions from the actual sample runs. Under well controlled and documented conditions this could represent an important move away from the paradigm of "same conditions for standards and sample". From all conditions tested, the most reliable molecular weight calibrations were obtained at elevated ionic strengths in the carrier solution (> 0.04 M) and low injected mass of PSS. However, even under these optimized conditions variations of up to 20% occur in the calculated molecular weights, and the recovery of NOM falls by up to 50% at high ionic strengths. Many applications aim for both correct molecular weight distribution and the measurement of low concentrations of elements bound to natural nanoparticles. We conclude, however, that finding conditions that are equally optimal for both of these analytical tasks is not always feasible. (C) 2011 Elsevier B.V. All rights reserved.