Soxhlet extraction automated

Glass Wool Plug Sample Aluminum beaker (cup) 

as would occur in a Kuderna-Danish concentrator. Since the concentration step is integrated in Soxtec, the extract is ready for cleanup and analysis. 

Lopez-Avila et al. [8] published a study in 1993 that evaluated the Soxtec extraction of 29 target compounds (seven nitroaromatic compounds, three haloethers, seven chlorinated hydrocarbons, and 12 organochlorine pesticides) from spiked sandy clay loam and clay loam. Among the five factors investigated (matrix type, spike level, anhydrous sodium sulfate addition, total extraction time, and immersion/extraction time ratio), matrix type, spike level, and total extraction time had the most pronounced effects on method performance at the 5% significance level for 16 of the 29 target compounds. The two solvent mixtures, hexane-acetone (1 1) and methylene chloride-acetone (1 1), performed equally well. Four compounds were not recovered at all, and apparently were lost from the spike matrix. Limited experimental work was performed with 64 base-neutral-acidic compounds spiked onto clay loam, and with three standard reference materials certified 

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Soxtherm can be used for a variety of substrates, such as plasticisers, and additives in plastics and rubber, fibre and textile coatings, colorants on textiles, fat in food, oils and lubricants, fertiliser coatings, etc. Specific reports are scarce. EPA method 3541 has adopted automated Soxhlet extraction [151]. 

U.S. Environmental Protection Agency (EPA), Method 3541, Automated Soxhlet Extraction (September 1994). 

Polycyclic aromatic hydrocarbons Automated Soxhlet extraction with ethyl acetate [85]... 

U.S. EPA. 1994. Method 3541 Automated Soxhlet Extraction 1.0. Scope and application. 

This chapter covers techniques for the extraction of semivolatile organics from solid matrices. The focus is on commonly used and commercially available techniques, which include Soxhlet extraction, automated Soxhlet extraction, ultrasonic extraction, supercritical fluid extraction (SFE), accelerated solvent extraction (ASE), and microwave-assisted extraction (MAE). The underlying principles, instrumentation, operational procedures, and selected applications of these techniques are described. In a given application, probably all the methods mentioned above will work, so it often boils down to identifying the most suitable one. Consequently, an effort is made to compare these methodologies. 

Soxhlet extraction and automated Soxhlet extraction are described in this section. Soxhlet extraction was named after Baron Yon Soxhlet, who introduced this method in the mid-nineteenth century. It had been the most widely used method until modern extraction techniques were developed in the 1980s. Today, Soxhlet is still a benchmark method for the extraction of semivolatile organics from solid samples. Automated Soxhlet extraction (Soxtec being its commercial name) offers a faster alternative to Soxhlet, with comparable extraction efficiency and lower solvent consumption. 

Distillation Soxhlet extraction and automated Soxhlet extraction... 

A fuUy automated Soxhlet extraction has been patented as Soxtec by Foss Tecator (Sweden) based on a four-step solvent extraction technique. The sample is rapidly dissolved during the first step in boiling solvent. The remaining soluble matter is efficiently removed at the second step, whUe distilled solvent is collected at the third step. In the fourth step, the sample cup lifts off the hot plate, utilizmg residual heat to predry while eliminating boil-dry risk. 

Automated Soxhlet extraction Polychlorinated biphenyls, organochlorine pesticides and semi-volatiles from soils, relatively dry sludges and solid wastes Allows equivalent extraction efficiency to Soxhlet extraction in 2 h... 

The improvements in Soxhlet extractions are high-pressure Soxhlet extraction (HPS), automated Soxhlet extraction (Soxhlet HT and Buchi B811) and focused microwave-assisted Soxhlet extraction (Soxwave and FMASE) as shown by Luque de Castro MD and Garcia-Ayuso in 1998. The solvents used for extraction are polar species (dimethyl formamide,... 

U.S. Environmental Protection Agency (EPA), Method 3541 Automated Soxhlet Extraction, Revision 0, In Online Test Methods for Evaluating Solid Waste Physical/Chemical Methods (SVP-846), Office of Sohd Waste, 1994, http //www.epa.gov/epaoswer/hazwaste/test/pdfs/3541. 

For many years, the traditional sample preparation methods, such as the Soxhlet extraction, were applied. Most of these methods have been used for more than 100 years, and they mostly require large amounts of organic solvents. These methods were tested during those times, and the analysts were familiar with the processes and protocols required. However, the trends in recent years are automation, short extraction times, and reduced organic solvent consumption. Modern approaches in solid sample preparation include microwave-assisted solvent extraction (MASE), pressurized liquid extraction, accelerated solvent extraction (ASE), matrix solid-phase dispersion (MSPD), automated Soxhlet extraction, supercritical fluid extraction (SEE), gas-phase extraction, etc. 

Sherma, J. Modem sample preparation technology, n. Automated SPME, ASE, SEE, MAE, automated Soxhlet extraction. Inside Lab. Manag. 2001, 5 (6), 33-38. 

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