This article introduces the tutorial for the Agilent Technologies Multimode Injector (MMI) and the use of Large Volume Injection (LVI) techniques to improve analysis. LVI techniques can increase the sample mass, resulting in larger peak areas and higher peak heights, leading to higher signal-to-noise ratios and lower detection limits. Additionally, LVI can reduce the initial sample processing volume.
This document serves as a guide for researchers exploring Large Volume Injection (LVI) techniques to improve trace analysis in gas chromatography. It explains how traditional injection methods limit sample volume and introduces the Agilent Multimode Injector (MMI) as a solution that allows injecting volumes from microliters up to a milliliter or more without distorting peaks.
The tutorial details three specific operational modes of the MMI: Splitless Hot, which is compatible with standard methods but can cause thermal degradation; Splitless Cold, which minimizes thermal stress by vaporizing samples at lower temperatures; and Solvent Purge mode, specifically designed for LVI to evaporate solvent before transferring analytes. The guide includes a step-by-step procedure using an FID MDL Checkout sample. This manual is written in Spanish.
The technique can be applied to volumes ranging from a few microliters up to one milliliter or more.
Normally only between 10% and 30% of the solvent enters the column and reaches the detector.
Most standard split/splitless injector liners have a nominal volume of one milliliter.