应用复杂基质导入技术分析莴苣豌豆中的农药残留

Difficult matrix introduction (DMI) is a relatively new technique that employs a microvial to hold the sample; this is then placed in a fritted liner and loaded into the Optic injector. Low sample volumes, and solids, can be placed in the microvial and the analytes directly transferred onto the column. A large sample volume may also be introduced and the solvent vented at a low temperature before transfer, as in a large volume injection. The injector is taken to a final temperature, calculated using Selective Exclusion, where the target analytes are transferred onto the column but the sample matrix is retained within the glass micro vial. The liner is then exchanged, manually or automatically, for a new liner/microvial containing the next sample. The liner can be re-used but the microvial is disposed of after use. Since contaminants are not able to build up in the system, the need for the clean up of crude extracts, and instrument maintenance, are reduced.