International standardization of an LC-MS/MS based food analytical method: development of a generally accepted test procedure for Alternaria toxins

There are more than seventy varieties of Alternaria toxins, but researchers have so far identified only a few of them structurally. The objective of this paper is to present a nearly ten-year process, during which an international standard for the simultaneous analysis of five Alternaria toxins in food samples was developed. This long process includes the development of the need for the standard and, in addition to the preparation and evaluation of the standardization tender, the development of the method, its validation and documentation. The paper focuses mainly on the development and validation of the analytical method, which is the longest and most labor-intensive part of the process, but in order to understand the overall picture, it is also necessary to emphasize the first and final steps. The development of a standard is a task of great responsibility for both the preparers of the standard and those involved in the validation and documentation of the standard, as the use of standardized methods is expected by the customers of the laboratories. On the other hand, laboratories that choose unique, self-developed methods can ascertain the accuracy and precision of their procedure by comparing them with the standard method. In this process that went on for nearly ten years, the original analytical method underwent several changes; the goal of these improvements was to make the procedure as simple and reproducible as possible. This is how the use isotope dilution mass spectrometry was reached through derivatization. It is important to emphasize that one of the goals of standardization is to have an appropriate analytical method available to authority laboratories for the testing of legally prescribed food contaminants, which procedure is available to any laboratory, however, it is questionable, whether the cost of the test covers its application. Consequently, it is not necessarily the most cost-effective analysis which is recommended by the standard, which may be the cause of conflict between the professional and economic managers of a laboratory in the case of private laboratories. The final form of the liquid chromatography/isotope dilution mass spectrometry (LC-IDMS) standard method developed for Alternaria toxins is likely to be approved and published by the European Committee for Standardization (CEN) in the end of 2021 (the standard has been issued since the article was submitted: CEN EN 17521:2021 Foodstuffs - Determination of Alternaria toxins in tomato, wheat and sunflower seeds by SPE clean-up and HPLC-MS/MS. The Editor). The standard will contain the determination of tenuazonic acid (TEA), altenuane (ALT), alternariol (AOH), tentoxin (TEN) and alternariol monomethyl ether (AME)

The role of populist parties in the geopolitical discourse in Lithuania

This thesis examines the geopolitical position of two non-mainstream, populist Lithuanian parties, Labour Party and Order and Justice, in several parliamentary debates dealing with geopolitically important issues. The study is based on electoral cleavage theory with the pro-soviet/anti-soviet cleavage identified as the main cleavage in Lithuania that partly overlaps with the winners/losers of transition and urban/rural cleavages. In the frame of quantitative and qualitative content analysis, several analytical categories are introduced, including topics, ideas and tactics used by the representatives of the parties. The analysis showed that Labour Party hardly displays any characteristics that would qualify them as strikingly pro-Russian, populist or a combination of these two, perhaps due to its ongoing transformation into a mainstream party. In the case of Order and Justice, what differentiates them from other Lithuanian parties and makes it interesting from the point of view of the research are the ideas that can be recognized from their rhetoric: these partly show resemblance with the official rhetoric of the Kremlin and partly mirror common notions about Russia. Populism in the case of these parties seems to mean rather identifying with the mind-set of a significant part of the population. As for the role of the two parties in the geopolitical discourse, the study concludes that they represent a voice in geopolitical matters that is to some extent different from the rhetoric of the mainstream parties, but they are not consequent enough, do not have a coherent set of ideas and lack a firm stance based on it. Their behaviour in geopolitical debates is rather opportunistic. Although they use some ideas that may originate from the Kremlin (‘double standards’, ‘depicting the EU and NATO as colonizers’) there is no sufficient evidence to state that they act as agents of Russia. The parties’ relative passivity and moderation in these debates can be explained by their lack of interest in geopolitical issues and general ideological emptiness pointed out by analysts as well as their possible fear of ostracism in case of harshly contradicting the mainstream geopolitical discourse and their presence in the government during most of the debates. Keywords: Lithuania, Russia, geopolitics, populism, cleavages, parliamentary rhetorichttp://www.ester.ee/record=b4614518*es

Determination of polar target components: HILIC-MS methods in food analysis

Hydrophilic Interaction Liquid Chromatography, abbreviated HILIC, has become one of the most dynamically developing branches of the liquid chromatography technique in recent years. Coupled with mass spectrometry detectors, HILIC-MS systems allow the separation of target components in complex samples, such as foodstuffs of plant or animal origin and feeds, that have been difficult or impossible to retain and detect using High Performance Liquid Chromatography (HPLC) earlier. This paper presents the possibility of using HILIC-MS to determine polar compounds through four specific examples. The test procedures presented include the analysis of a carcinogenic food contaminant, acrylamide, the determination of which in certain food groups is required by law. A further objective of this manuscript is to provide a detailed overview of the HILIC-MS method developed for the detection of water-soluble B vitamins added to foods. Several international standards have been developed for the analysis of B vita-mins, which offer determinations for each vitamin B separately. in comparison, most B vitamins can be measured together using the HILIC-MS technique. This option could be a big step forward for laboratories that analyze B vitamins regularly in a large number of samples. For people living with food intolerance, it is important to know the lactose content of milk-based foods. The HILIC-MS coupled system can also provide a fast and accurate solution for the detection of lactose present in low concentrations, the presentation of which is also the subject of this dissertation. Finally, the paper includes the determination of urea in feed samples. The law prescribes a photometric measurement of urea, but the reliability of this procedure at low concentration levels has been questioned and thus the HILIC-MS method has become prominent as an alternative solution. The applicability of the present analytical methods has been confirmed by successful participation in international proficiency testing programs, sufficiently accurate concentrations detected in control samples, and the certification of fully vali-dated methods by the National Accreditation Authority (NAH)

Folyadékkromatográfiás hármas kvadrupol rendszerű tandem tömegspektrometriás (HPLC-MS/MS) módszerek az élelmiszervizsgálatokban: kihívások és előnyök = Challenges and advantages in food analysis based on high performance liquid chromatorgaphy triple quadrupole tandem mass spectrometry (HPLC-MS/MS)

Az Európai Unióban az Európai Bizottság 37/2010-es rendelete határozza meg az állatgyógyászati szerek maradékainak határértékét az állati eredetű élelmiszerekben. A reziduumok analízise legtöbbször folyadékkromatográfiás elválasztástechnikai megoldást igényel optikai vagy tömegspektrometriás detektálással. Az utóbbi detektálási mód mára széleskörűen elterjedt az élelmiszervizsgáló laboratóriumokban, és nagyfokú szelektivitásának köszönhetően viszonylag egyszerűen alkalmazható komplex minták mérésére. A folyadékkromatográfiás elválasztással kapcsolt tömegspektrometriás detektálás esetén gyakorlatilag a minta-előkészítést egyetlen szilárd-folyadék extrakcióra és azt követő hígításra vagy oldószercserére lehet leegyszerűsíteni, ha szűrő (screening) módszerként kívánjuk alkalmazni az eljárást. Megerősítő (konfirmációs) módszernek használva az említett kapcsolt technikát, a mintatisztítás (clean-up) nélküli eljárás már csak izotóphígításos módszerrel összekötve valósítható meg az esetek többségében. Ugyanis a viszonylagos egyszerűséggel szemben a folyadékkromatográfiás - tömegspektrometriás módszerek az interferencia nélküli mérés ellenére is alapos optimálást igényelnek mind a minta-előkészítésben, mind az azt követő műszeres analízisben, mert a célkomponensekkel ko-eluálódó és méréstechnikailag láthatatlan mátrixalkotók a meghatározások pontosságát nagymértekben befolyásolhatják. A mátrixhatások kompenzációjára mátrixból felvett, mátrix alapú kalibrációt vagy izotóphígításos módszert szoktak alkalmazni, de ezen eljárások se adnak mindig jó vagy egyáltalán elérhető megoldást, így az optikai detektálás olykor jobbnak bizonyul (pl.: tetraciklinek meghatározása). Az izotóphígításos módszerek egy különleges változata a „pontosan egyező dupla izotóphígításos módszer” (exact-matching double isotope dilution mass spectrometry), amelynek elsődleges helye van kontrolminták referencia értékeinek meghatározásában. In the Europea Union, maximum residue limits of pharmacologically active substances are determined by Commission Regulation (EU) No 37/2010. Residue analysis usually requires liquid chromatographic separation, coupled with optical or mass spectrometric detection. The latter detection method has become widespread by now in food testing laboratories and, because of its high selectivity, it can be used relatively easily for the measurement of complex samples. In the case of mass spectrometric detection coupled with liquid chromatographic separation, sample preparation can be reduced practically to a solid-liquid extraction, followed by a dilution or a solvent exchange, if the procedure is to be used as a screening method. When using the abovementioned coupled technique as a confirmation method, in most cases a procedure without clean-up can only be achieved by coupling with an isotope dilution method. This is so, because - despite their relative simplicity and despite being a measurement with no interference - liquid chromatographic-mass spectrometric methods require thorough optimization both in sample preparation and in the subsequent instrumental analysis, because the accuracy of the measurements could be greatly influenced by matrix components that are co-eluted with the target components but which are invisible to the measurement technique. To compensate for matrix effects, matrix-matched calibration or the isotope dilution method is usually used, but even these procedures do not always provide good or even available solutions, and so optical detection sometimes proves to be better (e.g. the determination of tetracyclines). A unique variation of the isotope dilution method is the exact-matching double isotope dilution mass spectrometry, which has a special place in the determination of the reference values of control samples