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  2. Standard solution - Wikipedia

    en.wikipedia.org/wiki/Standard_solution

    Standard solutions are generally prepared by dissolving a solute of known mass into a solvent to a precise volume, or by diluting a solution of known concentration with more solvent. [1] A standard solution ideally has a high degree of purity and is stable enough that the concentration can be accurately measured after a long shelf time. [2]

  3. TAE buffer - Wikipedia

    en.wikipedia.org/wiki/TAE_buffer

    TAE buffer is commonly prepared as a 50× stock solution for laboratory use. A 50× stock solution can be prepared by dissolving 242 g Tris base in water, adding 57.1 ml glacial acetic acid, and 100 ml of 500 mM EDTA (pH 8.0) solution, and bringing the final volume up to 1 litre. This stock solution can be diluted 49:1 with water to make a 1× ...

  4. 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]

  5. Quantitative analysis (chemistry) - Wikipedia

    en.wikipedia.org/wiki/Quantitative_analysis...

    In the precipitation reactions the standard solution is in the most cases silver nitrate which is used as a reagent to react with the ions present in the sample and to form a highly insoluble precipitate. Precipitation methods are often called simply as argentometry. In the two other methods the situation is the same.

  6. Internal standard - Wikipedia

    en.wikipedia.org/wiki/Internal_standard

    In NMR spectroscopy, e.g. of the nuclei 1 H, 13 C and 29 Si, frequencies depend on the magnetic field, which is not the same across all experiments. Therefore, frequencies are reported as relative differences to tetramethylsilane (TMS), an internal standard that George Tiers proposed in 1958 and that the International Union of Pure and Applied Chemistry has since endorsed.

  7. Wet chemistry - Wikipedia

    en.wikipedia.org/wiki/Wet_chemistry

    Chemical tests use reagents to indicate the presence of a specific chemical in an unknown solution. The reagents cause a unique reaction to occur based on the chemical it reacts with, allowing one to know what chemical is in the solution. An example is Heller's test where a test tube containing proteins has strong acids added to it.

  8. Ellman's reagent - Wikipedia

    en.wikipedia.org/wiki/Ellman's_reagent

    This reaction is rapid and stoichiometric, with the addition of one mole of thiol releasing one mole of TNB. The TNB 2− is quantified in a spectrophotometer by measuring the absorbance of visible light at 412 nm, using an extinction coefficient of 14,150 M −1 cm −1 for dilute buffer solutions, [4] [5] and a coefficient of 13,700 M −1 cm −1 for high salt concentrations, such as 6 M ...

  9. Buffer solution - Wikipedia

    en.wikipedia.org/wiki/Buffer_solution

    A buffer solution is a solution where the pH does not change significantly on dilution or if an acid or base is added at constant temperature. [1] Its pH changes very little when a small amount of strong acid or base is added to it. Buffer solutions are used as a means of keeping pH at a nearly constant value in a wide variety of chemical ...