Liquid-liquid extractions are used to extract and concentrate an-alytes from aqueous matrices. This extraction technique is wide-ly accepted, as shown by its inclusion in many official methods. Analytical laboratories are looking to automation to help reduce solvent usage and increase sample throughput while ensuring the high quality of the resulting data.
The GERSTEL MultiPurpose Robotic Smart Series Sampler (MPS), commonly used for sample introduction into GC or HPLC, can perform a wide variety of sample preparation techniques using a single instrument and controlling software. The sampler can be configured as part of a GC or LC system or as a bench-top work-station.
In this study, the automation of the liquid-liquid extraction of fatty acid methyl esters in infant formula using the MPS is discussed. Two key GERSTEL options make automated extraction possible: (A) The Motion 40 agitator option that allows samples to be rapidly and effectively mixed, and (B) the M50 pump module that enables the precise delivery of the neutralization solution. The MAESTRO software enables the precise controlled timing required by this method. Automation of the extraction of infant formula samples and subsequent GC-FID determination of the FAMES listed in the official AOAC® 2012.13 Official MethodSM [1] are examined, and resulting precision and accuracy data are provided.