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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]
Standard addition involves adding known amounts of analyte to an unknown sample, a process known as spiking.By increasing the number of spikes, the analyst can extrapolate for the analyte concentration in the unknown that has not been spiked. [2]
Titration (also known as titrimetry [1] and volumetric analysis) is a common laboratory method of quantitative chemical analysis to determine the concentration of an identified analyte (a substance to be analyzed). A reagent, termed the titrant or titrator, [2] is prepared as a standard solution of known concentration and volume.
Sample preparation for mass spectrometry is used for the optimization of a sample for analysis in a mass spectrometer (MS). Each ionization method has certain factors that must be considered for that method to be successful, such as volume, concentration, sample phase, and composition of the analyte solution. Quite possibly the most important ...
However, the strong redox chemistry (SO 2 /I 2) means that redox-active sample constituents may react with the reagents. For this reason, KF is unsuitable for solutions containing e.g. dimethyl sulfoxide. KF has a high accuracy and precision, typically within 1% of available water, e.g. 3.00% appears as 2.97–3.03%.
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.
calculations and statistics: Protocols for methods that produce numerical results generally include detailed formulas for calculation of results. A formula may also be included for preparation of reagents and other solutions required for the work. Methods of statistical analysis may be included to guide interpretation of the data.
In analytical chemistry, sample preparation (working-up) refers to the ways in which a sample is treated prior to its analyses. Preparation is a very important step in most analytical techniques, because the techniques are often not responsive to the analyte in its in-situ form, or the results are distorted by interfering species .