# Recent Applications of Solid Phase Microextraction Coupled to Liquid Chromatography
## 2 Applications
### Food  
Food safety and quality control are great concerns for national and international regulatory committees and the scientific community. Therefore, food sample analysis constitutes one of the most important challenges in analytical chemistry and numerous scientists are highly focused on the enhancement of the speed and reliability of analytical processes, that should also be easy to perform, be cost-effective, require small amounts of solvents, provide a high selectivity, and be able to simultaneously detect multiple analytes. However, food-based matrices are complex and characterized by a wide range of chemical compositions that influence the performance of chemical analytical measurements, making sample preparation a crucial step before final analysis. SPME-LC represents a useful tool to face some of the analytical problems related to food. A comparison of the performances of four procedures, including QuEChERS, SPE, pressurized liquid extraction (PLE), and SPME, for the extraction of different organophosphorus (OPPs) and carbamates (CMs) insecticides from honey samples before LC-MS/MS analysis was reported by [PERSON] and co-workers [58]. All the approaches were successfully able to recover the selected analytes and the results obtained applying the four extraction techniques to real honey samples were similar. The five methods that will be described below have been developed using LC-UV as an analytical technique. This aspect could be considered by many as a liability due to the low selectivity and sensitivity of the technique, especially if compared to LC-MS. However, looking from a different perspective, it should be considered an added value, due to the low cost and reliability of a standard instrumentation that can be easily found in most laboratories. In fact, if a SPME-LC-UV analytical method can detect the target compounds at the concentration levels typically encountered in real matrices, even below the required maximum residue levels (MRLs), it could represent a very useful tool for cost-effective determinations. An SPME-LC-UV protocol (PDMS fiber) has been developed [59] and validated in terms of linearity, accuracy, precision, and sensitivity for the simultaneous determination of ten pesticides in mango fruits. The method was proposed as a fast screening prior to LC-MS analysis, even if it proved to be sensitive enough to detect some of the target compounds in mango samples at concentration levels below the Brazilian MRLs. A further SPME-LC-UV screening method for the simultaneous determination of six triazoles (diniconazole, fluquinconazole, flusilazole, myclobutanil, tebuconazole, and tetraconazole) in grape and apple fruit samples (peel, pulp, juice, and rain under the fruit trees) was fully validated by [PERSON] et al. [60]. The procedure was applied to real samples previously sprayed with commercial products containing the analytes and, eventually, myclobutanil and tebuconazole were found in the peel and rain, but not in pulp and juice samples. [PERSON] and co-workers successfully developed three different fast and simple SPME-LC-UV applications in various food matrices using commercially available fibers, on-line desorption, and LC isocratic conditions. The first work [61] reported the simultaneous determination of benzoic acid, salicylic acid, and some of its derivatives in fava beans, blueberries, kiwi, tangerines, lemons, oranges, and fruit juice (lemon and blueberry) samples, using a PDMS/DVB fiber, that was also the coating used in the development of another procedure for the simultaneous determination of major isoflav in soy milks and blended rice/soy beverages [62]. In the latter study, the binding constants of isoflav with serum albumin bovine were also defined to evaluate their bioavailability and to study the interaction with the main constituents in plants. A further method for the determination of free and total (after enzymatic deco conjugation of picedi) concentration of trans-resveratrol in wines, spirits, and grape juices [63], was carried out using a polyacrylate fiber.