Sampling System without Cross-contamination

The fourth major simplification of the procedure is to inject directly from the crimped vial to the HPLC system without a separation step. Fig. 12.3 shows the HPLC injection needle immersed in the aqueous phase sampling through the octanol phase without cross-contamination. 

Using a system such as this, small volumes of sample can be analyzed without the requirement of lengthy stabilization times, which are normally required for the continuous-flow approach.Time and sample are not wasted while the transport plumbing/nebulizer/spray chamber assemblies are stabilized with sample to ensure an equilibrated system that will produce reproducible results. In addition, preallocated time is not required between samples for washout to minimize cross-contamination problems. Short washout times result in sample processing rates of about 100 samples per hour. 

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