# Current Trends in Fully Automated On-Line Analytical Techniques for Beverage Analysis
## 6 On-Line Fully Automated Extraction-Chromatography-Mass Spectrometry  
Sample preparation is a determinant stage for the analysis success. This is mainly due to the fact that target analytes are usually present at low concentrations in complex matrices, which turns unable to analyze them directly in the analytical instrument, making necessary, and in many cases mandatory, a sample preparation step. Current trends in sample preparation and analysis are towards the development of a fully automated and more universal system involving extraction, chromatographic separation, detection and quantification (Figure 6), which allows the analysis to be done in a single stage [87]. This useful coupling while reducing the sample handling and analysis time will improve the detection and selectivity and allows the analyses of a large number of samples. From the analytical point of view, this system involves two steps. In the former, the sample preparation step, the analytes are extracted and cleaned-up from the matrix [87]. In this step are employed extraction techniques like SPE, turbulent flow, and miniaturized sample preparation approaches. Techniques as SPME and in-tube SPME are utilized, among others, which may be automated to allow on-line coupling with the second approach by a switching valve or interface, as we described in the previous numerals. In the second step, the analytes are transferred to the chromatographic system (LC or GC) to be separated and detected [87]. In the last decade, the coupling with tandem MS (MS/MS) has increased, offering an opportunity for an ideal detection and quantification system once this detector has the ability to confirm and discern the target analyte from related analytes based on the molecular mass and specific ion fragmentation. Briefly, tandem MS involve two sequential mass spectrometry analyzers. The first detects a target ion mass and separate it from the others ions produced in the ion source. Then, the isolated ion is fragmented in a collision cell and the second MS analyzer detects the ion fragments. Thus, the unique  
Figure 6: Schematic diagram representing a typical workflow employed in fully automated Extraction-Chromatography-Mass Spectrometry system. relationship between the precursor ion and its fragmented ions, attribute an unequivocal identification of the analyte [88]. This merger between a separation system and tandem MS analyzers is quite advantageous to both systems. Between the several advantages of this coupling are: (1) Specific relation between retention time and mass spectra as a confirmation parameter; (2) identification of co-eluting compounds due to the selectivity of the MS; (3) improvement on sensitivity and detectability, due to the analytes enter to the detector in a form of a single band reducing the interferences; (4) allows the analysis of complex matrices or samples in low quantity without requiring a laborious sample preparation, avoiding sample loss and saves time [88]. Nowadays, on-line fully automated extraction-chromatography-tandem mass spectrometry booming and has been widely applied in the analysis of different compounds in environmental, biological and food matrices. In beverages, this approach has also been applied for the trace analysis principally of contaminants and residues, among which stand out the multi-residue methodologies. Table 4 summarizes some applications of this approach in beverages analysis and shows the different configurations used between the extraction stage and the analysis technique. [PERSON] et al. [93] analyzed 128 multiclass pesticide residues (organophosphorus, organochlorines, carbamates, pyrethroids, triazines, amides, dinitroanilines, nitrogen heterocycles among others) present in tea samples using an HS-SPME coupled on-line to GC-Tandem mass. A PDMS/DVB fiber exhibited the best recoveries and broad extraction of the pesticides selected. The method showed good linearity and recoveries between 70 and 120% and got quantification limits below the maximum residue limits (MRLs) prescribed by EU.