固相萃取(SPE)

固相萃取(SPE)是一种用在色谱分析（如 HPLC、GC、TLC 色谱）前快速、选择性制备和纯化样品的技术，通过萃取、分配和/或吸附到固体固定相上，将一种或多种分析物从液体样品之中分离。

固相萃取样品制备可让样品从原始的基质环境转换为更简单的基质环境，由此使样品更适于后续色谱分析，往往可以简化并改善最终的定性和定量分析。此外，更简单的样品基质也更容易满足分析系统要求，更有益于延长系统使用寿命。

通过理想的固相萃取处理步骤，您可以：

• 让样品基质变得与目标色谱方法更兼容。
• 浓缩分析物（痕量富集）以提高灵敏度。
• 去除可能在色谱分析过程中引起高背景、误导性峰和/或灵敏度下降的干扰成分。
• 保护分析柱免受污染。
• 实现萃取工艺自动化。

相关技术文章

• Determination of Formaldehyde and Acetaldehyde in Air Using DNPH Cartridges and Automated On-Line Desorption Followed by HPLC
  Carbonyl compounds react within the DNPH cartridge to form immobilized hydrazones, which can be subjected to automated desorption and HPLC analysis with UV detection.
• The Effect of Container Materials on Production of Light Induced Off-Flavors in Milk – A Study Using SPME-GC-MS
  Various plastics used as barriers to the production of off-flavors in light exposed milk were examined using HS-SPME with a new Carboxen®/PDMS coated Nitinol fiber followed by GC-MS analysis allowing detection of low MW analytes at levels <1 ng/mL.
• Analysis of Pesticide Residues in Ginger Powder Using QuEChERS Extraction and Clean-up with a Novel Dual Layer SPE Cartridge
  The odor and pungency of ginger is due to the presence of terpenes, gingerols and shogaols. These compounds contribute to the highly complex matrix of ginger, which subsequently presents a challenge in low level analyses of contaminants. A novel 2-layer SPE cartridge efficiently reduces background for pesticide determination.
• Analysis of Pesticide Residues in Pistachios Using QuEChERS Extraction and Cleanup with Supel™ QuE Z-Sep+
  Pistachios contain approximately 45% fat, which can result in a significant amount of coextracted matrix in the acetonitrile extract generated using the QuEChERS procedure. A zirconia based adsorbent significantly reduces coextracted matrix prior to LC-MS or GC-MS.
• HybridSPE-Phospholipid Technology
  This Sigma-Aldrich article discusses how the HybridSPE-Phospholipid Technology works and how the phospholipids are removed.
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相关实验方案

• Determination of Trace Elements following EN 13805 using ICP-OES
  F&B, elemental analysis, inductively coupled plasma, regulatory, food safety, food chemistry, nutritional value.
• Allergenic Fragrance Testing – New Certified Reference Materials and GC-FID/GC-MS Application
  Last year, the International Fragrance Association (IFRA) published a new method for the testing of 57 potentially allergenic fragrances. We introduce two new dedicated certified reference materials (CRMs) and their analysis by GC using an ionic liquid capillary column, providing unique selectivity & stability.
• Analysis of Alkylphenols and Alkylphenol Ethoxylates Using new 13C-Labeled and Deuterated Internal Standards According to ISO 18857-2
  Alkylphenols are starting materials for the synthesis of alkylphenol ethoxylates, which are widely used as non ionic tensides, dispersive agents in paper and leather manufacturing, emulsifiers for pesticide formulations and as auxiliary agents for drilling and flotation.
• FAME Standard for Optimizing GC System Performance
  AOCS and AOAC methods for determining the trans fatty acid composition of foods by gas chromatography require the use of a highly polar cyanosilicone capillary column to provide the best peak resolution attainable of the numerous geometric (cis & trans) and positional isomers.
• Fast and Reliable Environmental Analysis of Aldehyde and Ketone Air Pollutants
  Aldehydes and ketones are ubiquitous air pollutants. Along with esters and ethers, they are major components of indoor air pollution and are therefore important for industrial hygiene applications.
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SPE原理

在SPE过程中，固定相（吸附剂或树脂）通过强效但可逆的相互作用与分析物或杂质结合，从复杂样品中可靠、快速地萃取目标分析物。

由于不同的分析物和基质有多种吸附剂和洗脱条件可选，故SPE兼具选择性和通用性。常见的SPE吸附剂包括：

• 硅基
  • 反相（C18、C8、氰基、苯基）
  • 正相（二氧化硅、二醇基、NH₂）
  • 离子交换（SAX，WCX，SCX）
• 碳基
• 基于聚合物（各种组分、不同功能）
• 其他吸附剂，例如Florisil^®（硅酸镁）或氧化铝
• 混合床：连续层形式的上述任意吸附剂组合

SPE策略

“吸附-洗脱SPE”：通过吸附剂捕获目标分析物，让基质干扰成分通过小柱。“干扰物去除SPE”：通过吸附剂捕获基质干扰成分，让目标分析物通过。HybridSPE和QuEChERS SPE方​​法均采用干扰物去除工作原理。

最适宜的SPE方法取决于分析物结构、溶解度、极性和亲脂性（分散系数）。我们为此提供了选择指南，可帮助根据自身目标应用选择最适宜的固定相和溶剂。

常见SPE应用

广泛用于制药、临床和高通量诊断检测、法医学、环境和食品/农业化学行业，适用于以下成分分析：

• 生物体液中的药物化合物和代谢产物
• 生物体液中的违禁药物
• 饮用水和污水中的环境污染物
• 食品/农业基质中的农药、抗生素或霉菌毒素
• 蛋白质和多肽脱盐
• 脂质组分分离
• 水溶和脂溶性维生素