LC/GC Certified Vials are UV-tested by HPLC. The HPLC test Vials are available in three closure types: crimp, snap, and screw cap. Each closure has its HPLC Vials & Closures - Chrom Tech. Chrom Tech offers a large selection of autosampler vials and closures, including HPLC vials, inserts, caps, and septa to suit your analytical needs. 100