Retention gaps, phenylmethyl silylated, low–medium polar Gradation - pH - 4.0 • 4.3 • 4.6 • 4.9 • 5.2 • 5.5 • 5.8 • 6.1 • 6.4 • 6.7 • 7.0 4-Methyl-1-hexene

4-Methyl-1-hexene

25G-NBOMe hydrochloride

10-Tetrahydrobenzo[a]pyren-7-ol

124Te16O *ICP-OES D

neat (oil)

Retention gaps, phenylmethyl silylated, low–medium polar Gradation - pH - 4.0 • 4.3 • 4.6 • 4.9 • 5.2 • 5.5 • 5.8 • 6.1 • 6.4 • 6.7 • 7.0 4-Methyl-1-hexeneThe retention gap technique in combination with on column injection allows concentration of a large sample volume in the capillary column. Retention gaps consist of uncoated (no stationary phase), deactivated fused silica capillary tubing. A retention gap must be inert without any noticeable retention (analytes are not retained). Phenylmethyl (low medium polar) deactivated tubing as an additional choice of surface deactivation. Improve peak shape by