Chrom Tech offers a large selection of autosampler vials and closures, including HPLC vials, inserts, caps, and septa to suit your analytical needs. Aijiren Certified Vials, Caps and Septa - Postnova. CombiPAL and GC PAL Liquid Injection Vials and Caps. Possible sample contamination Blue polypropylene cap, bonded pre-slit PTFE/silicone septa.