**1. Introduction**

The development of molecularly imprinted materials is an area of intense research ever since its introduction by Wulff and Sarhan in 1972 [1]. Generations of scientists have been intrigued

© 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. © 2018 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

by the binding phenomena involved in interactions that occur between natural molecular species such as antibodies and biological receptors. As such, over the years, numerous approaches have been used to mimic these interactions [2]. Molecular imprinting technology is today a viable synthetic approach to design robust molecular recognition materials able to mimic these natural phenomena. The main advantages of molecularly imprinted polymers (MIPs) are their high selectivity and affinity for the target molecule used in the imprinting procedure. Applications of molecularly imprinted materials have grown to include areas such as separation sciences and purification as extraction and chromatographic sorbents [3, 4], chemical sensors [5], catalysis [6], drug delivery [7] and biological antibodies and receptors system [8]. Among the polymeric materials developed, MIPs are also one of the most attractive materials for bioanalytical and biomedical applications [9]. Due to the high selectivity of MIPs towards pharmaceutical compounds, there are a number of companies that have gone to an extent of commercializing the MIP sorbent. These companies include Supelco in Belefonte (PA, USA), Biotage in Barcelona (Spain, Europe) and MIP Technologies in Lund (Sweden, Europe).

On the other hand, the occurrence of pharmaceutical compounds in the environment, particularly in surface water and wastewater, has also intrigued the scientific community. Pharmaceutical compounds are drugs that are used for the purpose of preventing, curing, treating disease and improving the health of their consumers [10]. To date, different classes of pharmaceuticals are known such as non-steroidal anti-inflammatory drugs (NSAIDs), antibiotics, antiretroviral drugs and steroid hormones. Pharmaceutical compounds enter the aquatic environment through various sources that include households, wastewater treatment plants (WWTPs), hospitals and industrial units [11]. Also, some pharmaceuticals are known to be transported into the environment through human excretion as metabolites and as unaltered parent compounds [12]. For example, the NSAIDs such as ibuprofen, naproxen, ketoprofen and diclofenac are eliminated from the human body with 10, 70, 80 and 10% of unaltered compounds, respectively [12]. The eliminated compounds are often swept into WWTPs. High number of research studies have demonstrated the inability of WWTPs to completely remove pharmaceuticals during the sewage treatment processes [13–15].

The formulation and the preparation of new pharmaceutical compounds conducted by companies can represent a danger for the environment because of their toxic potential. Despite concerns about potential risks associated with the presence of pharmaceuticals and personal care products in the environment, few toxicological data address the health and environmental effects of these compounds [16]. A recent review by Madikizela et al. [17] pointed out that there are indeed some traces of pharmaceutical compounds in water bodies even in many African counties that are least developed. Clofibric acid is regarded as one of the most persistent drug residues with an estimated persistence in the environment of 21 years, being frequently detected in environment monitoring of pharmaceuticals all around the world [18].

Conventional methods such as biodegradation, photo catalysis and advanced oxidation have been applied for the treatment of pharmaceutical contaminants [19]. Analytical tests are required for environmental monitoring of pharmaceutical drugs in order to evaluate the success of the treatment method. The complexity of the environmental samples has commanded the availability of selective analytical methods for the quantification of these pharmaceutical compounds. Therefore, MIPs are developed and used in sample preparation for the purpose of increasing selectivity of analytical method, and sensitivity when applied as a sorbent in the sample pre-concentration step. Other sorbents that have been used for the extraction of pharmaceuticals compounds include biochars, chitosan, silica, zeolites, graphene, clays and carbon [20].

by the binding phenomena involved in interactions that occur between natural molecular species such as antibodies and biological receptors. As such, over the years, numerous approaches have been used to mimic these interactions [2]. Molecular imprinting technology is today a viable synthetic approach to design robust molecular recognition materials able to mimic these natural phenomena. The main advantages of molecularly imprinted polymers (MIPs) are their high selectivity and affinity for the target molecule used in the imprinting procedure. Applications of molecularly imprinted materials have grown to include areas such as separation sciences and purification as extraction and chromatographic sorbents [3, 4], chemical sensors [5], catalysis [6], drug delivery [7] and biological antibodies and receptors system [8]. Among the polymeric materials developed, MIPs are also one of the most attractive materials for bioanalytical and biomedical applications [9]. Due to the high selectivity of MIPs towards pharmaceutical compounds, there are a number of companies that have gone to an extent of commercializing the MIP sorbent. These companies include Supelco in Belefonte (PA, USA), Biotage in Barcelona (Spain, Europe) and MIP Technologies in Lund (Sweden, Europe).

48 Recent Research in Polymerization

On the other hand, the occurrence of pharmaceutical compounds in the environment, particularly in surface water and wastewater, has also intrigued the scientific community. Pharmaceutical compounds are drugs that are used for the purpose of preventing, curing, treating disease and improving the health of their consumers [10]. To date, different classes of pharmaceuticals are known such as non-steroidal anti-inflammatory drugs (NSAIDs), antibiotics, antiretroviral drugs and steroid hormones. Pharmaceutical compounds enter the aquatic environment through various sources that include households, wastewater treatment plants (WWTPs), hospitals and industrial units [11]. Also, some pharmaceuticals are known to be transported into the environment through human excretion as metabolites and as unaltered parent compounds [12]. For example, the NSAIDs such as ibuprofen, naproxen, ketoprofen and diclofenac are eliminated from the human body with 10, 70, 80 and 10% of unaltered compounds, respectively [12]. The eliminated compounds are often swept into WWTPs. High number of research studies have demonstrated the inability of WWTPs to completely remove

The formulation and the preparation of new pharmaceutical compounds conducted by companies can represent a danger for the environment because of their toxic potential. Despite concerns about potential risks associated with the presence of pharmaceuticals and personal care products in the environment, few toxicological data address the health and environmental effects of these compounds [16]. A recent review by Madikizela et al. [17] pointed out that there are indeed some traces of pharmaceutical compounds in water bodies even in many African counties that are least developed. Clofibric acid is regarded as one of the most persistent drug residues with an estimated persistence in the environment of 21 years, being frequently detected in environment monitoring of pharmaceuticals all around the world [18].

Conventional methods such as biodegradation, photo catalysis and advanced oxidation have been applied for the treatment of pharmaceutical contaminants [19]. Analytical tests are required for environmental monitoring of pharmaceutical drugs in order to evaluate the success of the treatment method. The complexity of the environmental samples has commanded the availability of selective analytical methods for the quantification of these

pharmaceuticals during the sewage treatment processes [13–15].

Selectivity is an important parameter in analytical chemistry. However, many materials that are used for the extraction of pharmaceuticals such as hydrophilic lipophilic balance and C<sup>18</sup> sorbents lack this feature. On the other hand, MIPs have long since known to be attractive in this regard. **Figure 1** [21] shows the chromatograms (red line) which illustrates the efficiency of the molecularly imprinted polymer—solid-phase extraction (MIP-SPE) procedure (extraction rate of about 90%) and the advantages of both the concentration and sample clean-up with very low background and no interferences close to the retention time of 17β-estradiol. It is also noteworthy to point out that not only selectivity is enhanced but MIPs have also the capacity to pre-concentrate pharmaceutical compounds. This is especially important as pharmaceuticals are detected and quantified in very low concentrations. This further implies that other ordinary cheap instruments can be used for environmental analysis beside the mass spectrometry (MS) detection that is known to have low detection limits and can detect pharmaceuticals at trace levels.

**Figure 1.** HPLC-FLD chromatograms obtained after extracts clean-up with MIP-SPE (AFFINIMIP® SPE Estrogens; Polyintell) of 100 mL of seine water spiked at 0.5 ng.mL−1 with 17β-estradiol (—) and before MIP clean-up (—) [21].
