# Recent Applications of Solid Phase Microextraction Coupled to Liquid Chromatography
## 3 Conclusions  
SPME has undoubtedly become an established and ever-growing extraction technique. Its coupling with liquid chromatography has always been problematic due to the criticalities associated with the desorption process. Nevertheless, the SPME-LC applications to biological (Table 1), food, and environmental (Table 2) samples produced in recent years with commercial or already described fibers, reported in this review, are quite considerable and, added to the numerous SPME-LC works dedicated to the development of new extractive materials that will likely bring to a fast increase of commercial fibers, make clear the impact that this coupling continues to have in the analytical chemical context. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Application** & **Analyte** & **Matrix** & **Coating** & **Desorption** & **Detector** & **LOQ** & **Ref** \\ \hline \multirow{8}{*}{**Fluids and tissues**} & \multirow{2}{*}{\begin{tabular}{c} tranexamic acid \\ plasma \\ \end{tabular} } & human & \multirow{2}{*}{C18} & \multirow{2}{*}{off-line} & \multirow{2}{*}{MS/MS, QqQ} & \multirow{2}{*}{1.5 \(\mu\)g/mL} & [32] \\ \cline{2-2} \cline{6-7}  & & & & & & \\ \cline{2-2} \cline{6-7}  & \multirow{2}{*}{\begin{tabular}{c} \(\beta\)2-agonists \\ \end{tabular} } & \multirow{2}{*}{pig tissues} & PDMS/DVB & on-line & UV & 0.2–0.5 \(\mu\)g/L & [33] \\ \cline{2-2} \cline{6-7}  & & & CAR-PDMS & \multirow{2}{*}{off-line} & \multirow{2}{*}{UV/DAD} & \multirow{2}{*}{-} & [34] \\ \cline{2-2} \cline{6-7}  & & & & & & \\ \cline{2-2} \cline{6-7}  & \multirow{2}{*}{antibiotics} & human & \multirow{2}{*}{C18} & \multirow{2}{*}{off-line} & \multirow{2}{*}{MS/MS, QqQ} & \multirow{2}{*}{0.085–0.135 \(\mu\)g/mL} & [35] \\ \cline{2-2} \cline{6-7}  & & & & & & \\ \cline{2-2} \cline{6-7}  & & & & & & \\ \cline{2-2} \cline{6-7}  & \multirow{2}{*}{\begin{tabular}{c} methylphenidate \\ drugs \\ \end{tabular} } & human & \multirow{2}{*}{PDMS} & \multirow{2}{*}{\begin{tabular}{c} on-line \\ thermal \\ \end{tabular} } & \multirow{2}{*}{\begin{tabular}{c} direct \\ TD-ESI/MS \\ \end{tabular} } & \multirow{2}{*}{below 0.2 ng/mL} & [36] \\ \cline{2-2} \cline{6-7}  & \multirow{2}{*}{\begin{tabular}{c} psychotropic \\ drugs \\ \end{tabular} } & \multirow{2}{*}{\begin{tabular}{c} human \\ blood/bone \\ marrow \\ \end{tabular} } & \multirow{2}{*}{C18} & \multirow{2}{*}{off-line} & \multirow{2}{*}{\begin{tabular}{c} MS/MS, \\ QqTOF \\ \end{tabular} } & \multirow{2}{*}{5.60–42.80 ng/mL} & [37] \\ \hline \multirow{8}{*}{**In vivo**} & \multirow{2}{*}{\begin{tabular}{c} psychotropic \\ drugs \\ \end{tabular} } & \multirow{2}{*}{fishes bile} & PDMS & off-line & \multirow{2}{*}{MS/MS} & \multirow{2}{*}{-} & [38] \\ \cline{2-2} \cline{6-7}  & & & & & \\ \cline{1-1} \cline{2-2} \cline{6-7}  & \multirow{2}{*}{\begin{tabular}{c} psychotropic \\ drugs \\ \end{tabular} } & \multirow{2}{*}{trout muscle} & PDMS & off-line & \multirow{2}{*}{\begin{tabular}{c} MS/MS, \\ Qtrap \\ \end{tabular} } & \multirow{2}{*}{0.40–0.97 (ng/g)} & [39] \\ \cline{1-1} \cline{2-2} \cline{6-7}  & \multirow{2}{*}{\begin{tabular}{c} psychotropic \\ drugs \\ \end{tabular} } & \multirow{2}{*}{trout muscle} & PDMS & off-line & \multirow{2}{*}{\
\begin{tabular}{c} MS/MS, \\ Q40 \\ \end{tabular}} & \multirow{2}{*}{0.40–0.97 ng/g} & [40] \\ \cline{1-1} \cline{2-2} \cline{6-7}  & & & & & \\ \cline{1-1} \cline{2-2} \cline{6-7}  & \multirow{2}{*}{toral} & \multirow{2}{*}{mixed-mode} & \multirow{2}{*}{off-line} & \multirow{2}{*}{
\begin{tabular}{c} MS/MS, \\ Orbitrap \\ \end{tabular} } & \multirow{2}{*}{-} & [41] \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Biological applications of SPME-LC. As regards the desorption phase, several users and developers have turned to off-line desorption mode, which provides longer fiber lifetime due to the lower probability of damages in the interface and is still able to guarantee good results in terms of sensitivity. The disadvantage of this approach is a loss in terms of rapidity of analysis, which is not