Retention and variability of hydrogen (H₂) samples stored in plastic syringes

Abstract

The utility of two brands of 20 ml plastic syringes for storage of hydrogen (H₂) samples as obtained in H₂ breath tests were studied. Plastipak® syringes were found to be significantly better with regard to the stability of the H₂ concentration and the variability between the H₂ samples. Storage of the H₂ samples in Plastipak® syringes at 5 °C significantly improved the H₂ retention, whereas refrigeration of H₂ samples stored in Once® syringes did not reduce H₂ loss. Storage of H₂ samples in refrigerated plastic syringes is efficient and reliable for several days if syringes with minimal sample variation are used.

Key words:

• breath tests
• hydrogen
• plastic syringes