ASTM G120-95

It is expected that this test method will be suitable to identify and quantify contaminants found in systems, system materials, and components used in systems requiring a high level of cleanliness, such as oxygen. Softgoods such as seals and valve seats can be tested as received. Gloves and wipes, or samples thereof, to be used in the cleaning operation can be evaluated prior to use to ensure that the proposed cleaning solvent does not extract contaminants and residues on the surface to be cleaned.

Wipes or other cleaning equipment can be tested after use to determine the amount of contaminant removed from a surface. This procedure can be used to obtain samples for NVR analysis using contaminated control coupons that were subjected to the cleaning process as controls to validate cleaning operations.

The selection of the solvent requires some knowledge of the contaminant (see Practice G 93 for recommendations). If a nonvolatile residue (NVR) analysis is to be performed on the molecular contaminant, the boiling point of the solvent shall be significantly lower than that of the contaminant. For other analytical methods, the tester must know the accuracy of the analytical methods, and the solvent shall be chosen so as not to interfere with the selected analytical method. To identify the composition of the NVR, analytical methods such as infrared spectroscopy or gas chromatography/mass spectroscopy have been used satisfactorily.

1.1 This practice describes a procedure for the determination of residual contamination in systems and components requiring a high level of cleanliness, such as oxygen, by Soxhlet extraction.

1.2 This practice may be used for extracting nonvolatile and semivolatile residues from solids such as new and used gloves, new and used wipes, contaminated test specimens or control coupons, small pieces of hardware, component softgoods, etc. When used with proposed cleaning materials (wipes, gloves, etc.), this practice may be used to determine the potential of the proposed solvent to extract contaminants (plasticizers, residual detergents, brighteners, etc.) and deposit them on the surface being cleaned.

1.3 This practice is not suitable for the evaluation of particulate contamination.

1.4 The values stated in SI units are standard. Values in parentheses are for information only.

1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.