Automated multiple development

Multiple development is a promising path to improved separations by thin-layer chromatography (TLC). It offers enhanced resolution for samples of wide polarity, but requires complex and time consuming handling steps. After some early attempts, automated multiple development (AMD) became a commercial reality around 1990. As the name implies, it represents the convergence of multiple development and automation to mostly remove problems derived from its complexity. Over about 20 years, AMD has become a settled and useful development technique, which has steadily evolved with the practice of TLC. We present here a general description of its origins, capabilities, current applications, and possible future trends. Applications are classified into nine different groups: lipids, pesticides/environmental analysis/hazardous compounds, lubricants/additives/petroleum products, pharmaceuticals/clinical applications, organics, plant extracts/bioactive metabolites, food and food additives, carbohydrates, and explosives.