Simple steam distillation for sample preparation prior to gas chromatographic determination of organic compounds

Sample Preparation for Chromatographic Analysis

“…Probably the most common distillation method used as a form of sample preparation for Chromatographie analysis is steam distillation [31,32]. Solvent extraction and gas phase stripping methods are generally inefficient procedures for isolating polar, acidic, or basic compounds in an aqueous matrix due to the low efficiency of water immiscible solvents for the extraction of these compounds and their low volatility and high water affinity which results in a very slow transfer to the gas phase using sparging techniques.…”

“…Solvent extraction and gas phase stripping methods are generally inefficient procedures for isolating polar, acidic, or basic compounds in an aqueous matrix due to the low efficiency of water immiscible solvents for the extraction of these compounds and their low volatility and high water affinity which results in a very slow transfer to the gas phase using sparging techniques. The recovery of organic volatiles may be changed by simultaneous gas sparging, addition of a large amount of an inorganic salt, by pH adjustment, or by the addition of a codistiller, such as benzene or toluene [31][32][33][34]. In either case the volatile organic components are entrained and carried along with the steam at a rate proportional to their relative partial pressure and molecular weight at the temperature of the distillation.…”

Introducing Organic Chemistry Students to Natural Product Isolation Using Steam Distillation and Liquid Phase Extraction of Thymol, Camphor, and Citral, Monoterpenes Sharing a Unified Biosynthetic Precursor

“…The combined vapor pressures of the two compounds result in a lowered boiling point for the entire system. As a result, the water and volatile compounds codistil, which preserves the volatiles that could potentially decompose when exposed to higher temperatures. − This technique has been applied to several undergraduate isolation experiments including natural product isolation from spices, anise, , cloves, citrus fruits, , as well as others. − Teaching steam-distillation introduces a lab technique not often taught in undergraduate organic chemistry courses and extends the concept of simple distillation (often taught in the first semester of an organic lab course) to natural product isolation.…”

Isolation and Analysis of Essential Oils from Spices

“…Steam distillation is a simple, classic method of natural product isolation that avoids prolonged heating and possible decomposition of the organic compounds. ,− This method has been applied in many undergraduate laboratory experiments, including natural product isolation from clove, citrus, , anise, , and other sources. ,− Following distillation, the distillate is commonly extracted with dichloromethane. Alternative isolation methods, , such as cold-press extraction, solid-phase extraction, supercritical fluid extraction, − microwave-assisted distillation, − and ultrasound-assisted extraction, may also be applied to undergraduate laboratories. − …”