# Recent Applications of Solid Phase Microextraction Coupled to Liquid Chromatography
## 2 Applications
### Environmental  
To determine pollutants and/or the fate and impact of their potentially harmful degradation products in matrices of environmental interest, sensitive analytical methods to be applied to aqueous-based matrices that do not require the use of organic solvent are required. Furthermore, environmental samples are normally complex, and sample pre-treatment should be able to minimize interference arising from undesired interfering compounds. Considering that many contaminants are not suitable for GC analysis because of their physico-chemical properties, the SPME-LC approach represents an attractive choice to solve many of these analytical problems.  
To allow the SPME extraction and simultaneous LC-MS/MS determination of 16 drugs having acid and basic properties, urban wastewaters samples were split in two aliquots that were adjusted at pH 3 and 11, respectively, and extracted by two different Carbowax/Templated Resin (CW-TPR) fibers [64]. The fibers were then consecutively transferred in the desorption chamber for desorption in static mode and subsequent analysis. This original \"dual SPME\" approach permitted the quantification of all the analytes in influent and effluent wastewater treatment plant samples by means of a single chromatographic run. Another environmental application was focused on the SPME extraction (CW-TPR fiber) and LC-UV determination of chloramphenicol in tap and sea water [65]. Since the introduction of drugs into municipal sewage-treatment plants is often due to human excretion, the method was also applied to the determination of the analyte to urine samples. The optimized procedure required a simple sample pre-treatment, isocratic elution, and provided enough sensitivity for the analyte determination in the considered samples.  
An interesting study has considered for the first time the issues potentially caused in ESI-MS ionization by interferents extracted by the SPME fibers from complex matrices (environmental and biological) [66], finding significant enhancement or suppression of ionization in all the samples under investigation. Then, an isotopic internal standard method was developed and suggested as a tool to correct matrix effects in samples where its occurrence is unavoidable. A further work proposed a homemade interface to couple SPME (PDMS fiber) to LC-UV for the reliable and simultaneous determination of the antibacterial triclosan, triclocarbon, and four transformation products [67] in river water samples. More recently, the performances of three fibers (acrylate, nylon, and polydimethylsiloxane) for the extraction of endocrine disruptors (EDCs), triclosan, bisphenol A, and 17\(\alpha\)-ethinylestradiol, from seawater and for bioavailability studies were compared [68]. LC-MS/MS was used as analytical device, and acrylate fibers were demonstrated to be the most suitable for the analytes.  
A fast SPME-LC-MS/MS method (about 35 min of pre-treatment time) for the determination of tetrabromobisphenol A and hexabromocycldodecane, two currently used brominated flame retardants (BFRs), was developed [69] using spiked natural waters and subsequently applied to the analysis of tap water, even if the analytes were not found in the real matrix. Finally, the ultra-trace determination of sudan dyes in wastewater has been very recently reported [70] using two different extraction protocols, namely SPME and on-line SPE, in combination with LC-UV. As far as the SPME approach is concerned, using a PDMS/DVB coating, it was able to detect sudan I and II at sub-\(\upmu\)g/1 levels while sudan III and IV were not detectable at these levels likely due to strong binding to dissolved organic matter.