Methanol Extraction Study

 This application note discusses the processes used in USEPA Method 5035 for solid waste as it pertains to concentration levels that exceed the working calibration range used for low level analysis. Typically 200µg/kg is chosen as the highest calibration level. Any sample that exceeds this level must be reduced in response to fall within the calibration range. In this case, the high level soil is to be extracted using methanol as the extraction solvent. After the extraction is complete an aliquot of the methanolic portion of the sample is diluted in 5mL of de-ionized water. The sample is then transferred to a purge and trap for concentration under USEPA Method 5030. The determinative method for this paper is USEPA Method 8260b for use with a gas chromatograph coupled with a mass spectrometer. Several challenges arise from the implementation of this technique such as methanol interference and contamination, dilution error, extraction interference and carryover. The potential for human error and loss of volatiles during the extraction and dilution process are greatly reduced with this new automated technique.

Click here to download this Application Note.