Conclusions

The selectivity needed for the determination of targeted analytes in a complex matrix can be achieved anywhere in the analytical cycle. With a focus on the sample preparation portion, the concept of just enough sample preparation was presented. This concept relies heavily on the increased sensitivity and selectivity that can be achieved with tandem MS coupled with chromatographic separation. Provided that ion suppression and enhancement contributions are held to a minimum, Just enough sample preparation can provide the recoveries, minimum detectable limits and minimum detectable quantities consistent with the needs of the assay. However, as illustrated in the example of PAH analysis in fish, other selective detection principles such as fluorescence can also be used. A note of caution: in many essays, sample processing (handling) is still the ratedetermining step and just enough sample preparation may be insufficient to meet the needs of the assay. In these cases, moresophisticated sample preparation protocols such as SPE or liquid–liquid extraction may still be required.

Acknowledgments

Erratum

In the abstract of the August 2012 "Sample Preparation Perspectives" column (6) titled "Supported Liquid Extraction: The Best-Kept Secret in Sample Preparation," there was a difference from the normal practice in which the phases are used in SLE. The abstract should have read as follows: "In SLE, the same aqueous phases used in LLE are coated on an inert diatomaceous earth support, but instead of shaking the two immiscible phases together, the organic phase is passed through the column (or cartridge) and a very efficient extraction takes place."

Ronald E. Majors is the editor of "Sample Preparation Perspectives" and a senior scientist in the columns and supplies division at Agilent Technologies in Wilmington, Delaware, USA. He is also a member of LCGC Europe's editorial advisory board. Direct correspondence about this column should go to LCGC Europe editor, Alasdair Matheson, at Advanstar Communications, 4A Bridgegate Pavilion, Chester Business Park, Wrexham Road, Chester, CH4 9QH, UK, or e-mail amatheson@advanstar.com

References

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(6) R. Majors, LCGC Europe 25(8), 430–435 (2012).