###### Abstract  
In _t_-location due to the consumption of poppy seed teas has been reported due to their contamination with opium alkaloids (OAs). In this work, an efficient methodology based on microsolid-phase extraction (\(\upmu\)SPEed(r)) followed by gas chromatography-mass spectrometry (GC-MS) has been optimized to quantify five OAs in poppy seed teas. Nine cartridges (C4, C8, C18, silica, APS, PFAs, PS/DVB-RP, PS/DVB-SCX and PS/DVB-SAX), pH levels, cycles and elution solvents were evaluated. The method was validated and applied to study the transfer of OAs by evaluating water temperatures, infusion times and seed amounts. The highest transfer rates (71% for morphine, 96% for thebaine, and 100% for codeine, noscapine and papaverine) were achieved at 90\({}^{\circ}\)C, 5 min, with 4 g. These conditions were used to quantify the OAs in four teas prepared from different seeds. A high amount of morphine (1563 \(\upmu\)g/L) was found in one tea, indicating that the seeds had a concentration twice the maximum limit, highlighting the need to warn the population of this dangerous practice. food safety; opium alkaloids; \(\upmu\)SPEed; GC-MS; poppy seed tea; transfer; occurrence 00000-0000-0000-00000-00000-00000-00000-00000-00000-00000-00000-000000-000000-000000-000000-0000000-0  
have been considered Schedule II controlled substances, such that their commercialization has been made illegal [1]. However, in Europe, it was not until June 2022 that Regulation (EU) 2021/2142 was introduced, setting the maximum morphine equivalent limits (ME = morphine + 0.2 \(\times\) codeine) in seeds at 20 mg/kg [23]. To gain toxicologically relevant exposure data, it is important to determine the transfer of OAs from seeds to tea, which has not yet been studied. To this end, it is necessary to develop and validate analytical methods that are able to quantify the OAs present in tea infusions. For this, it is important to consider the crucial role that sample treatment plays in methods of food analysis, from purifying a sample extract to remove possible matrix interferences to preconcentrating to achieve lower detection limits. One of the most commonly used techniques to date is solid-phase extraction (SPE) [24]. However, miniaturized techniques are increasingly being selected as faster, cheaper and more environmentally friendly due to the smaller volumes of organic solvents and lower amounts of sorbents required [25], following the principles of green analytical chemistry (GAC). Many microextraction procedures with different formats and configurations have been developed. Microextraction by packed sorbents (MEPS) is an interesting miniaturization of the SPE technique which requires small amounts of sorbents. However, another configuration that presents some improvements to MEPS is the microsolid-phase extraction (\(\upmu\)SPE) technique [26]. This technique has been introduced to the market by the company EPREP, e.g., with \(\upmu\)SPead(Victoria, Australia), and is based on the use of cartridges containing sorbents with very small particle sizes, smaller than those used in MEPS (\(\leq\)3 \(\upmu\)m versus 50-60 \(\upmu\)m), resulting in larger surface areas. In addition, it involves a pressure-operated unidirectional valve (up to 1200 psi) to remove sample flow in one direction only, unlike the MEPS technique, which has two-directional flow potential (up and down) [26; 27]. In addition, there are a variety of sorbents for \(\upmu\)SPead(r) cartridges, such as unmodified and functionalized silica and polymeric materials, which allow the coverage of different retention interactions that may exist between various target analytes [27]. This technique has been used for the extraction of different families of compounds in foods, from bioactive compounds [27; 28] to natural toxins [29; 30]. However, as far as we know, this is the first time that \(\upmu\)SPead(r) has been used for quantifying OAs in foods.