Development of a universal sol-gel sorbent for fabric phase sorptive extraction and its application in tandem with high performance liquid chromatography-ultraviolet detection for the analysis of phthalates in environmental and drinking water samples

Most sorbent-based sample preparation methods are designed to interact with a class of analytes i.e., a polar sorbent for polar analytes, a non -polar sorbent for non -polar analytes, an ion-exchange sorbent for ionized compounds. A big challenge surfaces when making a choice of an appropriate sorbent when there is a mixture of compounds of varying polarities and ionization states in the complex sample matrices. Hence, the aim of this study was to develop a universal sol-gel sorbent coating for fabric phase sorptive extraction that would effectively and simultaneously extract polar, nonpolar, organic acids and bases via different intermolecular/interionic interactions. The universal sol-gel sorbent coated fabric phase sorptive extraction membrane was created by exploiting sol-gel surface coating technology to implant different functional moieties, ion exchanging ligands and an organic polymer that results in a 3-D organic-inorganic hybrid structure on the fabric substrate with a high level of selectivity/affinity for the target compounds. The preconcentrated extracts containing the isolated phthalates after the fabric phase sorptive extraction procedure were injected into the high -performance liquid chromatography-ultraviolet detection (HPLC-UV) system for the quantification. The FPSE-HPLC-UV method demonstrated a linear range between 50 and 1000 ng/mL for dimethyl phthalate, diethyl phthalate, dipropyl phthalate, diallyl phthalate, benzyl butyl phthalate, 1-10000 ng/mL for di-n-heptyl phthalate, 1-5000 ng/mL for di-n-heptyl phthalate, 10-5000 ng/mL for di-n-ethyl hexyl phthalate and 100-7500 ng/mL di-n-octyl phthalate. The intra-day and inter-day reproducibility (in terms of percentage relative standard deviation, %RSD) did not exceed 13.6. This method proves to be a selective, accurate, reproducible, cheap, and fast analytical approach for the quantitative and qualitative determination of the phthalates which is useful in crafting regulations for phthalates content in beverages and juices as well as in environmental monitoring.