Instrument: 7000 Headspace Autosampler
Method of Standard Additions for Calibration in Static Headspace Analysis: Analysis of Ethylene Oxide from PVC and HDPE
Static headspace analysis is frequently utilized to determine volatile organic components in a wide variety of matrices. When quantitating, instrument calibration is easily obtained when the standard matrix is identical to the sample matrix. The volatile constituents partition between the gas and liquid phases in the standard and the sample similarly. Known standards are prepared, a curve is generated bracketing the expected concentration range of the unknown, and the unknown concentration is determined by finding the point on the curve corresponding to the response.
Many times, however, the sample matrix is quite different from the standard matrix, or the sample matrix is unknown or uncertain. For these situations, the method of standard additions (MSA) is one technique to accomplish quantitation.
This paper describes the method of standard additions, and illustrates its application to the determination of ethylene oxide absorbed onto polyvinylchloride (PVC) and high density polyethylene (HDPE) samples. This technique is also applicable to the determination of residual monomers in simple and complex matrices, where standardization is difficult and solvent extraction/concentration is time consuming.
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