Isolation and quantitative methods for analysis of non-steroidal anti-inflammatory drugs

Non-steroidal anti-inflammatory drugs are widespread employed in both human and animal health care to reduce ongoing inflammation, pain and fever due to their anti-inflammatory, analgesic and, antipyretic actions. Apart from the well-known biological samples, nowadays these compounds are frequently found in the environment, leading to longterm exposure resulting in adverse effects on humans and wildlife. Therefore, it is important to develop analytical methodologies to detect and control the presence of these pharmaceuticals in very different kinds of samples, from urine, serum or plasma, to river and waste water, sediments or sewage sludge, most of them having very complex matrices. Other problems to solve are the low concentration of the target analytes, the presence of a great number of potential interferences and, sometimes, incompatibilities with the detection systems. Consequently, sample pre-treatment is a very important step to take into account in the non-steroidal anti-inflammatory drugs determination. Herein we reviewed the main extraction and clean-up procedures reported in the literature for these substances: ultrasonic extraction, Soxhlet extraction, pressurized- liquid extraction, supercritical fluid extraction, microwave-assisted extraction, dispersive liquid-liquid microextraction, hollow fiber liquid phase microextraction, pressurized hot water extraction, solid-phase extraction, molecularly imprinted solid-phase extraction and solid-phase microextraction. Several analytical methodologies have been developed to quantify non-steroidal anti-inflammatory drugs, including gas chromatography-mass spectrometry, liquid chromatography with ultraviolet detection, diode array detection, fluorescence detection and tandem mass spectrometry.