**4.5 Solid phase micro extraction (SPME) and GCMS method**

SPME is a solvent-free method that was developed by Pawliszyn in 1989 and combines sample extraction and concentration in a single process [44]. It consists of an organic phase-coated fiber that uses absorptive/adsorptive processes to selectively extract and concentrate the analytes present. SPME- GCMS procedure has mainly four steps that include extraction, derivatization, separation, and final detection. Ion exchange and gas chromatographic (GC) systems have been used to detect metal compounds directly from aquatic samples. The advantages of heavy metal determination include the availability of compound-sensitive, simple, cost-effective, and selective detectors (MS) with high-resolution power methods [45]. The recovery rate

**Figure 3.** *SPME-GCMS analysis protocol of TBT. Source: Schmidt and Podmore, [46].*

## *Heavy Metal Contamination in the Coastal Environment and Trace Level Identification DOI: http://dx.doi.org/10.5772/intechopen.106653*

of this method to detect the quantity of organotin (Sn) in marine water was found to be 88% by Bandara et al. [20].

Heavy metal usage and contamination of the environment could come from active maritime heavy boating and shipping activities in coastal areas, as well as other industrial activities. As a result, SPME is a cost-effective, precise, and sensitive standardized method to detect and quantify heavy metals at the parts per trillion level anywhere in the world (**Figure 3**).
