# Current Trends in Fully Automated On-Line Analytical Techniques for Beverage Analysis
## 3 Solid-Phase Microextraction (SPME)
### SPME Applications  
Several reports in the literature have successfully shown the use of SPME to generate efficient and satisfactory results to determine different classes of compounds in dietary matrices, highlighting food beverages. Since its development, applications with this technique have been increasing. Overview of applications of the SPME technique in both food and alcoholic beverages are presented in Table 2. Results have shown high sensitivity (low LODs), good selectivity, linearity, and chromatographic precision. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Matrix** & **Analyte** & **Fiber Coating** & \begin{tabular}{c} **Separation/** \\ **Detection** \\ \end{tabular} & \begin{tabular}{c} **LOD 1** \\ **(\#/L)** \\ \end{tabular} & **Ref.** \\ \hline Beer, carbonated drink, & \begin{tabular}{c} Phthalate acid \\ \end{tabular} & \begin{tabular}{c} Carbon nanotubes \\ \end{tabular} & GC-MS & 0.006–0.03 & [52] \\ wine, and white wine. & \begin{tabular}{c} Phthalate acid \\ \end{tabular} & \begin{tabular}{c} Carbon nanotubes \\ (MWCNTs)/silica \\ \end{tabular} & GC-MS & 0.006–0.03 & [52] \\ \hline Brazilian Pilsner beers & Off-flavors & DVB/CAR/PDMS & GC–ECD & 39.48–0.61 & [53] \\ \hline Chinese liquors & Pyrazines & CAR/DVB/PDMS & GC-NPD & 0.035–0.142 & [54] \\ \hline Fruit juice & Food colorants & \begin{tabular}{c} Diamino moiety functionalized \\ silica nanoparticles \\ \end{tabular} & CE & 30–360 & [55] \\ \hline Port wines & \begin{tabular}{c} Carbonyl \\ compounds \\ \end{tabular} & PDMS/DVB & GC-MS & 0.006–0.089 & [56] \\ \hline Soft drinks & Alcohols & \
\begin{tabular}{c} Poly(3,4-ethylenedioxythiophene)-ionic \\ liquid \\ \end{tabular} & GC-FID & 0.0342–0.0813 & [57] \\ \hline Teas &
\begin{tabular}{c} Benzoylurea \\ insecticide \\ \end{tabular} & \(\beta\)-cyclodextrinwith/attapulgeit-immobilized & HPLC & 0.12–0.21 & [58] \\ \hline Teas & Nerolidol & PDMS/DVB & GC-FID & 0.3 (\(\mu\)g/kg) & [59] \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Application of SPME as a sample preparation technique in the analysis of beverages. [PERSON] et al. [52] developed a procedure based on the combination of multi-walled carbon nanotubes (MWCNT)/silica reinforced hollow fiber solid-phase microextraction (HF-SPME) coupled to GC-MS to analyze phthalate acid esters (PAEs) in beverage samples. The method showed satisfactory recoveries (68-115%), results that were compared with those obtained using the solvent extraction, the official analysis method as per China's national standard. Dibutyl phthalate (DBP) and bis (2-ethylhexyl) phthalate (DEHP) were not found in all samples analyzed, whereas diethyl phthalate (DEP) was detected but could not be quantified in a red wine samples, obtaining detection limits between 0.006-0.03 ng/mL and quantification limits between 0.02-0.1 ng/mL. The well-defined peaks corresponding to the target analytes demonstrated that MWCNTs/SiO\({}_{2}\) HF-SPME was a proper extraction and cleaning procedure for the analysis of PAEs in real food samples. Another highlighted work was reported by [PERSON] and co-workers [55], who developed a method for the determination of four food dyes in beverage samples. In this work, it is reported for the first time the utilization of silica nanoparticles functionalized with diamino residues (dASNPs) as adsorbent in dispersive solid-phase microextraction (dSPME) were used as pseudo-stationary phase (PSPs) in capillary electrophoresis (CE) separation. The authors optimized all factors that influenced the process, obtaining a detection limit for the four dyes between 0.030 and 0.36 mg/L, which is low concerning those reported in similar works, and with recoveries between 82.7% and 114.6%. Finally, [PERSON] et al. [53] evaluated two analytical methods, headspace solid-phase microextraction combined with GC-MS (HS-SPME-GC-MS) and HS extraction in combination with GC-electron capture detection (HS-GC-ECD) for the analysis of off-flavors in Pilsner beer.