Lexikon

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solid phase extraction

a chromatographic technique used to prepare samples for subsequent analysis, an effective method to concentrate or isolate the non-volatile analytes. It is a kind of column chromatography. The extract is eluted through the column (cartridge) containing the preconditioned sorbent by applying vacuum. The substance of interest is retained on the column and all the interfering components are eluted or the interfering components are retained and the substance of interest is eluted. This sample preparation technique is suitable for any compounds. The low solvent need, no need of concentration by evaporation and in this way avoiding the concentration of the polluting components, cheap sorbents, saving time, no emulsion formation, enhanced selectivity and potential for automatization are the advantages of SPE over the traditional liquid/liquid extraction (LLE).

solid phase microextraction
chemical extraction performed with a fiber coated with an extracting phase (solid or liquid). The coated fibers (with 5-10 micrometer coating) are used to isolate and concentrate analytes into the coating material. In the case of volatile compounds the fiber is kept in the headspace, in the case of non-volatile analytes the fiber is kept in the liquid to reach the equilibrium. After extraction, the fibers are transferred, with the help of the syringe-like handling device, to analytical instruments for separation and quantification of the target analytes. Desorption is performed by heat (gas chromatography) or by elution (liquid chromatography). The concentration in the coating of the fiber is proportional with that in the sample. The extraction is fast, easy to be automated, simple, can be done without solvents, and detection limits can reach parts per trillion (ppt) levels for certain compounds.
sonication assisted extraction

a physical technique employing ultrasound to intensely vibrate a sample media in extracting solvent and to maximise solvent/analyte interactions. Abbreviated as SAE, widely used for extracting the contaminants from soil.

Soxhlet extraction

an extraction technique of solids in which the sample is repeatedly contacted with solvent over several hours, increasing the extraction efficiency. Soxhlet extraction is a purification technique developed by Franz von Soxhlet in 1879. The solid is put into a paper "thimble" which is then placed into the main chamber of the Soxhlet extractor. The solvent is heated to reflux and then travels up the distillation arm and floods into the main chamber with the thimble. The chamber then slowly fills and some of the pure compound will dissolve into the solvent. The chamber is emptied with the help of the side arm and the cycle repeats. See also http://chemistry.hull.ac.uk/labweb/glossary_soxhlet.php#

stir-bar sorptive extraction
a new solventless sample preparation method for the extraction and enrichment of organic compounds from aqueous matrices. The method called also as Twister technique is based on the same principles as solid-phase microextraction (SPME). Compared with SPME, a relatively large amount of extracting phase (SPME 0.5 microliters; Twister 50 microliters) is coated on a stir bar. Solutes are extracted into the coating poly(dimethyl siloxane, PDMS) of a stir-bar, based upon their octanol-water partitioning coefficient. In contrast to SPME, in which desorption is performed in the inlet of a gas chromatograph, stir-bar sorptive extraction is used in combination with a thermal-desorption system. After desorption the stir-bar can be used again. The technique has been applied successfully to trace analysis in environmental, biomedical and food applications, e.g. for determination of trace hydrocarbons, PAHs, PCBs in water. Users can obtain extremely low detection limits with good reproducibility. (Source: F. David, B. Tienpont and P. Sandra: Stir-Bar Sorptive Extraction of Trace Organic Compounds from Aqueous Matrices, LCGC Europe, 2003, 1-7)
supercritical fluid extraction
an extraction method (SCFE) where the extraction fluid, usually CO2 is present at a pressure and temperature above its critical point.
treatment of contaminated groundwater, water-extracts and leachates
unprotected groundwater extraction plant
verbal characterisation of risk of chemicals

67/548/EEC regulation uses the following riks-phrases for characterisation of the risk of dangerous chemical substances.

Risk Phrases

R1: Explosive when dry

R2: Risk of explosion by shock, friction, fire or other sources of ignition

R3: Extreme risk of explosion by shock, friction, fire or other sources of ignition

R4: Forms very sensitive explosive metallic compounds

R5: Heating may cause an explosion

R6: Explosive with or without contact with air

R7: May cause fire

R8: Contact with combustible material may cause fire

R9: Explosive when mixed with combustible material

R10: Flammable

R11: Highly flammable

R12: Extremely flammable

R14: Reacts violently with water

R15: Contact with water liberates extremely flammable gases

R16: Explosive when mixed with oxidising substances

R17: Spontaneously flammable in air

R18: In use, may form flammable/explosive vapour-air mixture

R19: May form explosive peroxides

R20: Harmful by inhalation

R21: Harmful in contact with skin

R22: Harmful if swallowed

R23: Toxic by inhalation

R24: Toxic in contact with skin

R25: Toxic if swallowed

R26: Very toxic by inhalation

R27: Very toxic in contact with skin

R28: Very toxic if swallowed

R29: Contact with water liberates toxic gas.

R30: Can become highly flammable in use

R31: Contact with acids liberates toxic gas

R32: Contact with acids liberates very toxic gas

R33: Danger of cumulative effects

R34: Causes burns

R35: Causes severe burns

R36: Irritating to eyes

R37: Irritating to respiratory system

R38: Irritating to skin

R39: Danger of very serious irreversible effects

R40: Limited evidence of a carcinogenic effect

R41: Risk of serious damage to eyes

R42: May cause sensitisation by inhalation

R43: May cause sensitisation by skin contact

R44: Risk of explosion if heated under confinement

R45: May cause cancer

R46: May cause heritable genetic damage

R48: Danger of serious damage to health by prolonged exposure

R49: May cause cancer by inhalation

R50: Very toxic to aquatic organisms

R51: Toxic to aquatic organisms

R52: Harmful to aquatic organisms

R53: May cause long-term adverse effects in the aquatic environment

R54: Toxic to flora

R55: Toxic to fauna

R56: Toxic to soil organisms

R57: Toxic to bees

R58: May cause long-term adverse effects in the environment

R59: Dangerous for the ozone layer

R60: May impair fertility

R61: May cause harm to the unborn child

R62: Possible risk of impaired fertility

R63: Possible risk of harm to the unborn child

R64: May cause harm to breast-fed babies

R65: Harmful: may cause lung damage if swallowed

R66: Repeated exposure may cause skin dryness or cracking

R67: Vapours may cause drowsiness and dizziness

R68: Possible risk of irreversible effects

Combinations

R14/15: Reacts violently with water, liberating extremely flammable gases

R15/29: Contact with water liberates toxic, extremely flammable gases

R20/21: Harmful by inhalation and in contact with skin

R20/22: Harmful by inhalation and if swallowed

R20/21/22: Harmful by inhalation, in contact with skin and if swallowed

R21/22: Harmful in contact with skin and if swallowed

R23/24: Toxic by inhalation and in contact with skin

R23/25: Toxic by inhalation and if swallowed

R23/24/25: Toxic by inhalation, in contact with skin and if swallowed

R24/25: Toxic in contact with skin and if swallowed

R26/27: Very toxic by inhalation and in contact with skin

R26/28: Very toxic by inhalation and if swallowed

R26/27/28: Very toxic by inhalation, in contact with skin and if swallowed

R27/28: Very toxic in contact with skin and if swallowed

R36/37: Irritating to eyes and respiratory system

R36/38: Irritating to eyes and skin

R36/37/38: Irritating to eyes, respiratory system and skin

R37/38: Irritating to respiratory system and skin

R39/23: Toxic: danger of very serious irreversible effects through inhalation

R39/24: Toxic: danger of very serious irreversible effects in contact with skin

R39/25: Toxic: danger of very serious irreversible effects if swallowed

R39/23/24: Toxic: danger of very serious irreversible effects through inhalation and in contact with skin

R39/23/25: Toxic: danger of very serious irreversible effects through inhalation and if swallowed

R39/24/25: Toxic: danger of very serious irreversible effects in contact with skin and if swallowed

R39/23/24/25: Toxic: danger of very serious irreversible effects through inhalation, in contact with skin and if swallowed

R39/26: Very Toxic: danger of very serious irreversible effects through inhalation

R39/27: Very Toxic: danger of very serious irreversible effects in contact with skin

R39/28: Very Toxic: danger of very serious irreversible effects if swallowed

R39/26/27: Very Toxic: danger of very serious irreversible effects through inhalation and in contact with skin

R39/26/28: Very Toxic: danger of very serious irreversible effects through inhalation and if swallowed

R39/27/28: Very Toxic: danger of very serious irreversible effects in contact with skin and if swallowed

R39/26/27/28: Very Toxic: danger of very serious irreversible effects through inhalation, in contact with skin and if swallowed

R42/43: May cause sensitization by inhalation and skin contact

R48/20: Harmful: danger of serious damage to health by prolonged exposure through inhalation

R48/21: Harmful: danger of serious damage to health by prolonged exposure in contact with skin

R48/22: Harmful: danger of serious damage to health by prolonged exposure if swallowed

R48/20/21: Harmful: danger of serious damage to health by prolonged exposure through inhalation and in contact with skin

R48/20/22: Harmful: danger of serious damage to health by prolonged exposure through inhalation and if swallowed

R48/21/22: Harmful: danger of serious damage to health by prolonged exposure in contact with skin and if swallowed

R48/20/21/22: Harmful: danger of serious damage to health by prolonged exposure through inhalation, in contact with skin and if swallowed

R48/23: Toxic: danger of serious damage to health by prolonged exposure through inhalation

R48/24: Toxic: danger of serious damage to health by prolonged exposure in contact with skin

R48/25: Toxic: danger of serious damage to health by prolonged exposure if swallowed

R48/23/24: Toxic: danger of serious damage to health by prolonged exposure through inhalation and in contact with skin

R48/23/25: Toxic: danger of serious damage to health by prolonged exposure through inhalation and if swallowed

R48/24/25: Toxic: danger of serious damage to health by prolonged exposure in contact with skin and if swallowed

R48/23/24/25: Toxic: danger of serious damage to health by prolonged exposure through inhalation, in contact with skin and if swallowed

R50/53: Very toxic to aquatic organisms, may cause long-term adverse effects in the aquatic environment

R51/53: Toxic to aquatic organisms, may cause long-term adverse effects in the aquatic environment

R52/53: Harmful to aquatic organisms, may cause long-term adverse effects in the aquatic environment

R68/20: Harmful: possible risk of irreversible effects through inhalation

R68/21: Harmful: possible risk of irreversible effects in contact with skin

R68/22: Harmful: possible risk of irreversible effects if swallowed

R68/20/21: Harmful: possible risk of irreversible effects through inhalation and in contact with skin

R68/20/22: Harmful: possible risk of irreversible effects through inhalation and if swallowed

R68/21/22: Harmful: possible risk of irreversible effects in contact with skin and if swallowed

R68/20/21/22: Harmful: possible risk of irreversible effects through inhalation, in contact with skin and if swallowed

R-Phrases no longer in use

R13: Extremely flammable liquefied gas.

R47: May cause birth defects.

water extraction well