1992-09-01_REVISION - M1988112 - Laserfiche WebLink

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~ •//~ ' Western Atlas CORE LABORATORIES Interrast~anal .,.,.ro.,r ca... ~ :r• ANALYTICAL CHEMISTRY DIVISION QUALITY ASSURANCE MANUAL SOP N0. REVISION N0. EFFECTIVE 047E PAGE HC-QAC-02 0 1/06/92 69 of 104 ' Standards are analyzed to measure the accuracy of laboratory analyses. Performance criteria for specific standard types are provideQ in the applicable analytical method. General inorganic guidelines are provided in Section 13.6. Calibration Standards ' Calibration standards are a series of formulated samples of precisely known concentrations of the target analytes in the expected range. Calibration standards define the working range and linearity of the analytical ' method and establish the relationship of the instrument response to the target analyte concentration used to quantity field samples . The frequency, number of calibration points, and acceptance criteria for ' calibration standards varies considerably with the method. Calibration requirements for each method and instrument are taught during analytical ' method training. External Reference Standard ' External reference standards are standards of known analyte concentration obtained from an external source (EPA, NIST, etc.) other than the source, ' of the standards which are used for instrument calibration. External reference standards are used to verify the accuracy of the' ' calibration standards. i At a minimum, external reference standards are analyzed after each initial ~ calibration. Frequency and acceptance criteria for external reference ~ standard analyses vary considerably with the method. Requirements fort ' each method and instrument are taught during analytical method training. Laboratorv Control Standard ILCSI i t Laboratory control standards (LCS) are standards of kftown analyte concentration which are added to an interference-free matrix, such as, laboratory pure water or solvent.