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  2. Van Deemter equation - Wikipedia

    en.wikipedia.org/wiki/Van_Deemter_equation

    For a packed column, the cross-sectional area of the column exit flow path is usually taken as 0.6 times the cross-sectional area of the column. Alternatively, the linear velocity can be taken as the ratio of the column length to the dead time. If the mobile phase is a gas, then the pressure correction must be applied.

  3. High-performance liquid chromatography - Wikipedia

    en.wikipedia.org/wiki/High-performance_liquid...

    HPLC has many applications in both laboratory and clinical science. It is a common technique used in pharmaceutical development, as it is a dependable way to obtain and ensure product purity. [59] While HPLC can produce extremely high quality (pure) products, it is not always the primary method used in the production of bulk drug materials. [60]

  4. Micellar liquid chromatography - Wikipedia

    en.wikipedia.org/wiki/Micellar_liquid_chromatography

    In HPLC, the capacity factor represents the molar ratio of the solute in the stationary phase to the mobile phase. The capacity factor is easily measure based on retention times of the compound and any unretained compound. The equation rewritten by Guermouche et al. [9] is presented here: 1/k¢ = [n • (KMW-1)/(f • KSW)] • CM +1/(f • KSW ...

  5. Darcy's law - Wikipedia

    en.wikipedia.org/wiki/Darcy's_law

    Darcy's law is an equation that describes the flow of a fluid flow trough a porous medium and through a Hele-Shaw cell.The law was formulated by Henry Darcy based on results of experiments [1] on the flow of water through beds of sand, forming the basis of hydrogeology, a branch of earth sciences.

  6. Calibration curve - Wikipedia

    en.wikipedia.org/wiki/Calibration_curve

    A calibration curve plot showing limit of detection (LOD), limit of quantification (LOQ), dynamic range, and limit of linearity (LOL).. In analytical chemistry, a calibration curve, also known as a standard curve, is a general method for determining the concentration of a substance in an unknown sample by comparing the unknown to a set of standard samples of known concentration. [1]

  7. High-performance thin-layer chromatography - Wikipedia

    en.wikipedia.org/wiki/High-performance_thin...

    The spot capacity (analogous to peak capacity in HPLC) can be increased by developing the plate with two different solvents, using two-dimensional chromatography. [8] The procedure begins with development of a sample loaded plate with first solvent. After removing it, the plate is rotated 90° and developed with a second solvent.

  8. Gas chromatography - Wikipedia

    en.wikipedia.org/wiki/Gas_chromatography

    The linear velocity will be implemented by means of the carrier gas flow rate, with regards to the inner diameter of the column. With GCs made before the 1990s, carrier flow rate was controlled indirectly by controlling the carrier inlet pressure, or "column head pressure".

  9. Time-of-flight mass spectrometry - Wikipedia

    en.wikipedia.org/wiki/Time-of-flight_mass...

    The velocity of the charged particle after acceleration will not change since it moves in a field-free time-of-flight tube. The velocity of the particle can be determined in a time-of-flight tube since the length of the path (d) of the flight of the ion is known and the time of the flight of the ion (t) can be measured using a transient digitizer or time to digital converter.