ASTM D7558 Colorimetric/Spectrophotometric Procedure

Scope:

Dialkyldithiocarbamates (DTCs), benzothiazoles, and thiurams are regularly utilized as vulcanization gas pedals in NRL items. A UV spectrophotometer with recognition at 320 nm is used to gauge the ZDTC, mercaptobenzothiazole, and thiurams in the ASTM D7558 test method. 

Procedure:

In ASTM D7558, the elastic material is cut into tiny pieces, and around 1 g is set into the extraction vessel. Acetonitrile is added to give a last volume/weight of 10 mL acetonitrile per gram of elastic. The acetonitrile extricate is recuperated and centrifuged. Zinc dibutyl dithiocarbamate (ZDBC) is added as per guidelines at 500 to 31.25 μg/mL in the acetonitrile. Every individual arrangement is blended and later hatched for 120 min at 50-65°C. All samples are blended thoroughly, and the standard is estimated at 320 nm on a UV spectrophotometer. Contingent on the number of tests tried, this test strategy takes around five hours to finish.

Video 01: What is Colorimetry

Specimen size:

Polypropylene or glass extraction tubes, with screw top lids (50 mL, conical bottom) and polypropylene cryotubes are required for ASTM D7558 testing.

Data:

The report for ASTM D7558 testing will incorporate a portrayal of the elastic gadget, including item and parcel number, when accessible. The gas pedal should be communicated in μg/g and μg/dm².

Conclusion:

ASTM D7558 is intended to evaluate how much absolute extractable gas pedals are in regular elastic-plastic (NRL) and nitrile gloves.