Molecular imprints as sorbents for solid phase extraction: potential and applications
Molecular imprints as sorbents for solid phase extraction: potential and applications
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DOI：
10.1039/a806379f
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发表时间：
1998
期刊：
影响因子：
--
通讯作者：
J. Olsen;Paul D. Martin;I. Wilson
中科院分区：
文献类型：
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作者：
J. Olsen;Paul D. Martin;I. Wilson
固相萃取 (SPE) 通常用于分析化学的许多不同领域。一些主要领域是环境和药物分析，其中样品的清洁和浓缩是分析方案中的重要步骤。 SPE 的发展很大程度上是以液-液萃取 (LLE) 为代价的，其中 SPE 相对于 LLE 的明显优点是它消耗的有机溶剂更少，并且可以利用更广泛的萃取机制。传统上，固相材料包括反相吸附剂，例如C18、C8，正相吸附剂，例如硅胶和二醇，以及离子交换吸附剂，例如SCX和SAX。吸附剂要发挥作用，必须能够实现选择性萃取。分子印迹聚合物 (MIP) 可能比传统材料提供更高程度的选择性，这可能在样品制备方面具有优势。尽管分析化学分子印迹的新概念是在近 50 年前由 Dickey1 等人提出的。然而，回顾最近的文献表明，直到最近十年，特别是最近五年，分子印迹的使用才得以确立。分子印迹涉及制备具有针对某些分子的特定识别位点的聚合物。 MIP 的合成是通过在模板分子周围组装单体并随后使用合适的交联剂进行聚合来实现的，从而得到刚性且坚固的材料。随后去除模板分子，为聚合物提供识别位点（空腔），从而允许模板分子特异性重新结合。这种识别是由于形状和物理化学性质，例如氢键、离子相互作用和疏水相互作用。 2 由于MIP 提供的特异性识别，这些材料应该适用于需要高选择性和亲和力结合的领域。MIP 的结合能力可以与形状的抗体的结合能力相比较，在结合中起着重要作用。然而，与抗体相比，MIP 至少具有潜在的优势。因此，MIP 可以使用标准（且易于理解）的化学方法轻松快速地制备，并且在高温和有机溶剂中稳定。相比之下，免疫反应本质上是不可预测、不可重复的，并且可能需要很长时间才能实现。 3 由于其类似抗体的行为，分子印记已被探索的分析领域之一是作为抗体替代品的免疫测定。 4-6 MIP 的适用性得到广泛研究的另一个领域是在 HPLC 中作为手性固定相。 7 然而，分子印迹的特征作为固相萃取 (MIP-SPE) 的吸附剂也很有吸引力，如此处所讨论的。
Solid phase extraction (SPE) is routinely used in many different areas of analytical chemistry. Some of the main fields are environmental and pharmaceutical analysis where cleaning and concentration of the sample are important steps in the analytical protocol. The growth of SPE has largely been at the expense of liquid–liquid extraction (LLE) where the perceived advantages of SPE over LLE are that it consumes less organic solvents and that a wider range of extraction mechanisms can be utilised. Conventionally, solid phase materials have included reversedphase sorbents, such as C18, C8, normal phases such as silica gel and diol and ion exchange sorbents such as SCX and SAX. For a sorbent to be useful it must enable selective extractions to be achieved. Molecularly imprinted polymers (MIPs) potentially offer a higher degree of selectivity than conventional materials which may give an advantage in sample preparation. Although a new concept for analytical chemistry molecular imprinting was introduced nearly 50 years ago by Dickey1 and others. Reviewing the more recent literature reveals, however, that it is only in the last decade, and especially in the last five years, that the use of molecular imprinting has become established. Molecular imprinting involves the preparation of a polymer with specific recognition sites for certain molecules. The synthesis of MIPs take place by assembly of monomers around a template molecule and subsequent polymerisation using a suitable cross-linker, giving a rigid and robust material. Subsequent removal of template molecules provides a polymer with recognition sites (cavities) allowing specific rebinding of template molecule. The recognition is due to shape and physicochemical properties such as hydrogen bonding, ionic interactions and hydrophobic interactions. 2 Due to the specific recognition offered by MIPs these materials should be applicable in fields where binding with high selectivity and affinity is required.The binding ability of MIPs can be likened to that of antibodies in that shape plays an important role in binding. However, at least potentially, MIPs present a number of advantages compared to antibodies. Thus MIPs are easily and rapidly prepared using standard (and well understood) chemical methods, and are stable at high temperatures and in organic solvents. By comparison, immune responses are by nature unpredictable, irreproducible and can require long periods of time to achieve. 3 Due to their antibody-like behaviour one of the areas of analysis where molecular imprints have been explored is in immunoassay as antibody substitutes. 4–6 Another area where the applicability of MIPs extensively have been investigated is in HPLC as chiral stationary phases. 7 However, the features of molecular imprints are also attractive as sorbents for solid phase extraction (MIP-SPE) as discussed here.