HPLC, GC/MS, NMR nomenclature

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    HPLC, GC/MS, NMR nomenclature


    Just some info on what those tests actually mean from the cannabis FAQ:-

    High Performance Liquid Chromatography: Usually used to detect
    anabolic steroids. Defined by Thein and Landry:

    High-performance liquid chromatography is similar to GC, except a
    liquid carries the sample through the chromotographic columns and
    the columns are not placed in a heated compartment.
    High-performance liquid chromatography is both sensitive and
    specific, and it is simpler and faster than GC. Gas
    chromatography and HPLC are reliable methods for screening, and
    they allow for simultaneous determination of a wide variety of
    different compounds. High-performance liquid chromatography is
    used to screen for urinary caffeine levels and has been used to
    confirm the positive results obtained from other screening
    techniques. Some steroids can be analyzed with this technique,
    whereas HPLC and GC lack appropriate sensitivity to detect
    beta-adrenergic blockers.

    2.3: Gas Chromatography: Defined by Thein and Landry:

    Gas chromatography uses a separation technique to divide the urine
    extracts into the component parts. An inert gas carries the urine
    through chromatographic columns, and the samples are separated by
    their boiling temperature and by their affinity for the column.
    Compounds are identified by separation time, called retention
    time. The retention time is unique and reproducible for each drug
    in a given chromotographic column.

    2.6 Gas Chromatography / Mass Spectrometry: Defined by Thein and Landry:

    The most precise procedure for detection of banned substances is a
    combination of GC and MS. Gas chromatography/mass spectrometry is
    a two-step process, where GC separates the sample into its
    constituent parts, while MS provides the exact molecular
    identification of the compounds. Compounds are separated by GC
    and are then introduced, one at a time, into a mass spectrometer.
    As the sample constituents enter the MS, they are bombarded by
    electrons, which cause the compound to break up into molecular
    fragments. The fragmentation pattern is reproducible and
    characteristic, and is considered the "molecular-fingerprint" of a
    specific compound. Gas chromatography/mass spectrometry is
    considered to be the most definitive method for confirming the
    presence of a drug in the urine and is approximately 100 to 1,000
    times more sensitive than TLC. Selective ion monitoring has been
    used to improve the GC/MS results. This procedure is the most
    costly, averaging approximately $200 per sample to test.

    Nuclear Magnetic Resonance Spectroscopy (NMR)
    http://www.ch.ic.ac.uk/local/organic/nmr.html

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    that price is for non-chemists only

    and NMR will not be used in drug tests..

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