This test method is of particular use as a quality control tool for a molding or synthesis operation. Acetaldehyde is a volatile degradation product generated during melt processing of PET. Thus, it becomes trapped in the sidewalls of a molded article and desorbs slowly into the contents packaged therein. In some foods and beverages AA can impart an off-taste that is undesirable, thus, it is important to know its concentration in PET articles that are to be used in food contact applications.

The desorption conditions of 150 C for 60 min are such that no measurable AA is generated by the sample during the desorption process.

1. Scope

1.1 This test method covers a gas chromatographic procedure for the determination of the ppm residual acetaldehyde (AA) present in poly(ethylene terephthalate) (PET) homo-polymers and co-polymers which are used in the manufacture of beverage bottles. This includes sample types of both amorphous and solid-stated pellet and preform samples, as opposed to the bottle test, Test Method D4509, an acetaldehyde test requiring 24 h of desorption time at 23°C into the bottle headspace and then the concentration of the headspace quantified by a similar GC method.

1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.3 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.

2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.

ASTM Standards

D4509 Test Methods for Determining the 24-Hour Gas (AIR) Space Acetaldehyde Content of Freshly Blown PET Bottles

E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method

Keywords

AA test; acetaldehyde; carbonated soft drink; ground parison AA; PET bottles; 24 hours headspace; water; Acetaldehyde (AA); Flame ionization detectors (FID); Headspace gas chromatography; Headspace sampler; Polyethylene terephthalate bottle polymer; Polymers;

ICS Code

ICS Number Code 55.100 (Bottles. Pots. Jars)

Citing ASTM Standards

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