Vials (volume 2 mL, clear glass vial (standard opening - 4.6 mm), O.D. × H × I.D. 12 mm × 32 mm × 4.6 mm, thread 8-425) are suitable basically to inject samples from an autosampler. Autosampler needle pierces through the cap during injection and withdraws the required aliquots of sample from the vials. Vials, screw top with solid green thermoset cap with PTFE liner, preassembled, pkg of 100 has been used to perform naphthalene biosensor solution assay to determine naphthalene content in gas and aqueous phases by use of a Pseudomonas putida biosensor.