Download as PDF, PPTX
Uploaded byBhupander Kumar
Pressurized accelerated extraction of pollutants
Accelerated solvent extraction (ASE) is a technique that uses solvents, elevated temperatures, and pressures to efficiently extract analytes from solid samples. It provides several advantages over traditional techniques like Soxhlet extraction, including requiring smaller sample and solvent volumes and shorter extraction times. Key factors that influence ASE extraction include sample preparation, solvent selection, temperature, pressure, static time, flush volume, and number of cycles. These parameters require optimization for different sample matrixes and target analytes. ASE is useful for extracting pesticides, PAHs, PCBs, and dioxins from soils, sediments, plants and other solid environmental samples.
More Related Content
Similar to Pressurized accelerated extraction of pollutants
Pressurized accelerated extraction of pollutants
- 1. Solid Sample Extractionfor Pesticides, PCBs, PAHs and Dioxin/Furans Analysis using Accelerated Solvent Extraction (ASE) System Bhupander Kumar Scientist National Reference Trace Organics Laboratory Central Pollution Control Board East Arjun Nagar Delhi-110032
- 2. Principles of Extraction Physical and chemical processes influence solid-liquid extractions – Diffusion – Viscosity – Surface tension – Solubility – Binding energy of physio-chemico sorption interactions
- 3. Principles of Extraction General improvement of chemical processes as temperature increases – Diffusion increases, viscosity decreases, surface tension decreases, solubility increases, and solute interactions with matrix are decreased “Like dissolves like” principle is important – Polar solvent for polar analytes Particle size influences extraction rate
- 4. Common Sample ExtractionTechniques Soxhlet Sonication Microwave Automated Soxhlet Accelerated Solvent Extraction
- 5. Comparison of LiquidExtraction Techniques Techniques Sample Size (g) Solvent Vol. (ml) Average Extraction Time* (hours) Soxhlet 10 – 30 300 – 500 4 – 48 Sonication 30 300 – 400 0.5 – 1 Microwave 5 30 0.5 - 1 Automated Soxhlet 10 50 0.5 – 2 ASE 10 - 100 15 - 120 0.2 – 0.5 *Extraction times are based on a per sample basis. This estimate of time does not include sample weighing, sample loading, or sample concentration.
- 6. What is AcceleratedSolvent Extractor (ASE) ? ASE is a technique for extracting solid and semi-solid samples with liquid solvents ASE Uses elevated temperatures (40- 200oC) and pressures (1500-2000 psi) Uses small quantities of solvent and short periods of time -15 mL and 15 min for 10 g samples ASE can be used to replace Soxhlet, Sonication, Boiling, Wrist Shaker, and other extraction methods
- 7. Comparison of extractionfor Dioxin and Furans by ASE and Soxhlet ASE Soxhlet Sample size 4 – 10 grams 4 – 10 grams Solvent Toluene Toluene Solvent volume (ml) 15 250 Temperature o C 150 - 180 << Boiling point Pressure 10 MPs Atmospheric Time 2 x10 min 18 hours
- 8. Environmental Matrices* Soils, Sludges,Sediments Plant and animal tissues Air Samples – Glass filters – Quartz filters – Tenax resins – Charcoal adsorbents – PUF and XAD resins Essentially all solid or semi-solid matrices analyzed for environmental contaminants * Pesticides, Herbicides, Semi-volatiles, PAHs, PCBs ,PCDDs and PCDFs ASE Application Areas
- 9. Food Matrices Food contaminantanalysis – Pesticides – Herbicides – PCBs – PAHs – dioxins, etc. Component analysis – Lipid content – Flavors – aromas, etc. ASE Application Areas
- 10. ASE 350 ASE 200 ASE300 Different Models of ASE
- 11. Solvent Pump Purge Valve Oven Nitrogen Static Valve Collection Vial Extraction Cell Fill withTime (min) solvent 0.5-1 Load cell Static Extraction 5 Purge with 1 - 2 nitrogen cycle Heat and 5 pressurize Extract Total (min) ready 12 - 14 Flush with 0.5 fresh solvent ASE Schematic
- 12. ASE 350 ASE350 automated extraction system for solid and semisolid samples Extraction of 24 sample at a time in various size of cells (1, 2, 10, 22, 34, 66, and 100 ml) Collection vessels are 60 and 250 ml size Three 2L solvents can be hold Temp. limit 4000 C Work at pressure of 1500 - 2000 psi Can use single solvents or gradient of solvent Typical extraction times of 15 min per sample Extraction solvent volumes of 40–150 mL Solvents Control panel Collection tray with vessels Extraction cells
- 13.
- 14. Cell Loading Addfilter to cell Weigh sample Mix Sample with dispersant – ASE prep DE or Ottawa sand Fill empty space with sand or DE Transfer sample to cell using ASE funnel Add surrogate or other tracer compounds Add filter (optional) and Cap cell Load cell in extraction tray
- 15. Extraction Cell inCell Oven
- 16. ASE Operation (run asample) Check solvents and gases. 6 step start-up Prepare cells Load cells Load collection vials Select method or schedule Select vial or bottle Press start
- 17. Extraction Cell incell tray Collection vial in vial tray
- 18. Methods Optimization inASE Sample preparation or pretreatment – Grinding – Dispersing – Drying
- 19. Grinding Sample withlarger particles should be ground Efficient extraction requires minimum particle size generally < 0.5 mm Grinding can be done by mortar and pestle or electric grinder and mills
- 20. Dispersing The aggregationof sample particles prevent efficient extraction Dispersing with samples that tends to compact in cell outlet Samples with fine particles can adhere tightly to each other under high pressure Dispersing can be achieved by ASE Prep DE (Diatomaceous earth) or Ottawa sand Sea sand is not recommended because it contains very small particles which block system Run dispersing extraction blank to verify its cleanliness
- 21. Drying Wet sampleprevent non-polar solvents from reaching the target analyte Sample drying prior to extraction is the way to handle wet samples Drying is normally done by adding ASE Prep DE Cellulose may be used for very wet samples like fruits and vegetables Magnesium sulfate is not recommended due to its melting at high temp. Sodium sulfate is also not recommended because it could solubilize and can deposited in exit line Following ratios have been applied to various samples Sample that appear dry: 4 g sample to 1 g DE Sample that appear wet: 4 g sample to 2 g DE
- 22. Examples of SamplePreparation Sample Type Sample preparation Wet soil/sediment 10 g sample with 5 g of ASE Prep DE or Ottawa sand Fish tissue (80 % moisture) 3 g sample with 2 g of ASE Prep DE or Ottawa sand Fruit / vegetables 10 g sample with 5 g of ASE Prep DE or Ottawa sand or 2 g cellulose Creams/lotions 2 g sample with 3 g of ASE Prep DE or Ottawa sand Ground polymer 1 – 3 g sample with 1 – 3 g of ASE Prep DE or Ottawa sand
- 23. ASE Extraction Parameters Solvent Pressure Temperature Static Time Flush Volume Purge Time Cycles
- 24. Solvents Solvent mustbe able to solubilize the target analytes while leaving the sample matrix intact For efficient extraction “Like dissolves like” principle is important Solvent mixture of different polarities can be used to extract broad range of compounds Solvents with aqueous buffers can be used in ASE Strong acids (HCl, HNO3,H2SO4) are not recommended, due to their ability to react with the stainless steel in the system
- 25. Temperature Start at100ºC or 20ºC below the analyte/matrix degradation point Run multiple extractions on same sample at 100º C Increase temperature to improve recoveries Be aware of thermal limitations of sample and analytes 1000 C is better for pesticides, herbicides, PCBs and PAHs 1500 C is better for Dioxin/furans
- 26. Pressure Start at1500 -2000 psi Consider lower pressures for samples likely to compress For most samples pressure has no noticeable effect Maximum pressure is 2000 psi ASE 200, 300 and 350 are set at 1500 psi
- 27. Extraction Time Increasedextraction time – Allows longer time for analyte diffusion Improved recovery obtained with some samples Increased number of static cycles gives better results
- 28. Static Time Cycles Static extraction cycles – Better to have multiple cycles than one long cycle » Two 5-min cycles are good than one 10-min cycle » Five 2-min cycles even better
- 29. Flush Volume Solventvolume goes into cell Set at 60% of cell volume When used with multiple static cycle, flush volume per cycle is the total % divided by the number of cycles 1 cycle with 60% flush volume 2 cycle with 30% 3 cycle with 20%
- 30. Purge Time Purposeis to get solvent out of cell; no impact on recovery of analytes Set purge time for 30-45 seconds per 11 mL of cell volume (90-135 sec for 33-mL cell) Increase purge time for densely packed samples Increase purge time for non-volatile solvents Increase purge time for larger cells: 66-mL or 100-mL cells
- 31. Achieve Selectivity Solventchoice – Adjust polarity Selective sorbents – Alumina for fat retention Temperature – Higher temperature = more co-extractables Combinations of the above
- 32. Check ASE ExtractionParameters If recoveries are low: 1) Increase the temperature 2) Add static cycles 3) Increase the static time 4) Select a different solvent Diagnostic skill – Rinse test – Run three blanks: check weight of solvent collected – RSD: 3% or less
- 33. ASE Parameters for PCDDs/Fsand PCBs Conditions PCDDs/Fs PCBs Matrix Soil, sludge, sed. Etc (10 g) PUF Fish tissue (10 g) Sediment (10 g) Solvent Toluene Hexane Hexane Acetone/hexane (1:1) Temp. 1500C 1000C 1250C 1500C Pressure 2000 psi 1500 psi 1500 psi 1500 psi Heatup time 5 min 5 min 6 min 7 min Static time 10 min 5 min 5 min 7 min Flush volume 60 % 60 % 60 % 60 % Purge time 125s 100s 100s 180s No. of static cycles 3 1 2 3
- 34. ASE Parameters for Herbicides,Pesticides, and PAHs Conditions Herbicides Pesticides PAHs Matrix Soil, sludge, sed. (10 g) Soil, sludge, sed. (10 g) Soil, sludge, sed. (7 g) Solvent DCM/acetone (1:2) hexane/acetone (1:1) DCM/acetone (1:1) Temp. 1000C 1000C 1000C Pressure 2000 psi 1500 psi 1500 psi Heat up time 5 min 5 min 5 min Static time 5 min 5 min 5 min Flush volume 60 % 60 % 60 % Purge time 60s 60s 60 s No. of static cycles 3 3 3
- 35. ASE Parameters for POPs(pesticides, HCB, PCBs, PCDDs/Fs) with Hexane, DCM, Acetone, Toluene Conditions Pesticides & PCBs HCB PCDDs/Fs Matrix Soil, sludge. Sediments, Dust, biological Solvent Hexane/acetone (1:1) DCM/acetone (1:1) Toluene Temp. 1000 C 1000 C 1500 C Pressure 1500 psi 1500 psi 1500 psi Heat up time 5 min 5 min 7 min Static time 5 min 5 min 10 min Flush volume 60 % 60 % 70 % Purge time 100 s 100 s 120 s No. of static cycles 2 2 3
- 36. ASE Parameters for XAD- 2 (AMBERLITE) Resin Conditions Cleaning Elution Solvent Acetone (100%) - one extraction Hexane/acetone (25:75) – one extraction Hexane/acetone (50:50) – 3 extraction Hexane/acetone (50:50) Temp. 750C 750C Pressure 1000 psi 1000 psi Heat up time 5 min 5 min Static time 5 min 5 min Flush volume 150 % 150 % Purge time 120 s 120 s No. of static cycles 5 3
- 37. Thank you foryour attention! bhupander_kumar@yahoo.com 42102378, 9212135238 GO WITH ASE TO SAVE TIME, ENERGY AND ENVIRONMENT WITH ADEQUATE ACCURACY……!!