## 1 Introduction
This is of special interest in the case of complex samples where the presence of interference could prevent final quantification by typical chromatographic techniques coupled to common detectors [25; 26]. Mass spectrometry is the most commonly used analytical technique in the trace analysis of organic compounds. It is used as a separate tool with different sources of ionization or is often coupled with other analytical techniques, e.g., HPLC. As shown in publications, some organic compounds can be determined using direct mass spectrometry [27; 28]. However, in the case of trace analysis, which includes NSAID analysis, it is necessary to preconcentrate the analyte. A great solution is to use selective MIPs for this, which preconcentrate the analyte and isolate it from the sample matrix. An additional advantage is the lack of interference by other chemical compounds present in the sample. MIPs are mainly used as sorption materials for sample preconcentration in HPLC-MS analysis. However, they are increasingly used in various fields of chemistry, e.g., as a layer of selective coating on electrodes in electrochemical analysis. In this way, antigens can be analyzed using specific antibodies. However, the process of manufacturing the electrode, optimizing its working conditions, and performing the analysis is much more complicated, time-consuming, and cost-intensive than flowing atmospheric-pressure afterglow (FAPA)-MS analysis [29]. Unfortunately, analysis of proteins by FAPA-MS is not possible due to their high molecular weight. However, when it comes to analyzing organic compounds with low molecular weight, this method is very fast, simple, and cheap. You can use commercially available MIPs or make them by simple synthesis. The analyte enclosed in the MIP polymer structure is additionally stable for a longer period of time, crucial for, e.g., estrogen analysis [23]. The analyte in MIPs can be easily transported and stored. The FAPA-MS analytical technique using MIPs is very simple and does not require additional instrumentation; we skip the sample preparation stages, the analysis is carried out directly from MIPs, the number of errors decreases, the method is repeatable, and its time does not exceed 5 min. Ionization techniques at atmospheric pressure deserve special attention in mass spectrometry. Ambient ionization mass spectrometry comprises a group of various techniquesthat allow MS analysis at atmospheric pressure. They provide rapid, direct, and high-throughput analyses with no or only minimal sample pretreatment. Moreover, substances can be analyzed directly from surfaces or other matrixes. FAPA-MS techniques involve the generation of a direct current or radiofrequency electrical discharge between a pair of electrodes in contact with a flowing inert gas, creating a stream of ionized molecules, radicals, excited state neutral atoms, and electrons. The plasma species are directed towards the sample, resulting in desorption and ionization of the analyte. Ambient plasma MS techniques have many advantages due to their simple instrumentation, rugged construction of the measuring system, no need for solvents, and generation of singly charged analyte species that are easier to identify than multiply charged ions and various adducts produced by the spray-based techniques [30; 31; 32; 33; 34; 35]. We propose the use of commercially available AFFINILUTETMMIP-NSAIDs columns to pre-isolate and preconcentrate NSAIDs from solutions, followed by direct analysis using the FAPA ionization source. The obtained results are presented and compared with results obtained via the standard way of analysis by the HPLC-MS method.