Stability of plasma electrolytes in Barricor and PST II tubes under different storage conditions

Introduction: Sample stability can be influenced by many different factors; evaporation and leakage from residual cells are the most relevant factors for electrolytes. During the analytical phase, samples are usually kept uncapped at room temperature. Once samples are processed, they are usually stored sealed and refrigerated. Long turnaround time and the possibility of “add-on test” need consideration for electrolyte stability. The aim of our study is to examine short-term electrolyte stability in this two-common laboratory working conditions in two different lithium heparin plasma tubes (Barricor and PST II, Becton Dickinson). Materials and methods: In 39 plasma samples from voluntary subjects we measured sodium (Na+), potassium (K+) and chloride (Cl–) at 6 time points since centrifugation (0h, 3h, 6h, 9h, 12h and 15h). Maximum allowable bias (clinically significant change) was based in SEQC (Sociedad Espanola de Química Clínica) recommendations; 1% for Cl–, 0.6% for Na+ and 4% for K+. Results: In open room temperature tubes, clinically significant changes appeared in Na+ and Cl– after 3 hours and in K+ after 9 hours in both types of tubes. In refrigerated sealed tubes, all the analytes were clinically stable up to 12 hours in both kinds of plasma tubes. We observed a statistically significant progressive increase in K+ levels, which was less pronounced in Barricor tubes. Conclusion: Stability of electrolytes is compromised after 3 hours in open tubes and after 12 hours in sealed tubes

Pre-Conference Field Trip. Monogenetic volcanism of the Catalan Volcanic Zone: Maar craters, scoria cones and rootless volcanoes of the Garrotxa volcanic field, and open fossil excavation in a Pliocene maar cráter. 7th international MAAR CONFERENCE

The field trip will start May 18 at the bus station of Olot at 7:30 am. During the first half of the day, participants will explore and discuss the evolution of La Crosa de Sant Dalmai maar volcano, the largest maar crater of the Iberian Peninsula, formed during the Pleistocene. Then, the group will debate on the stratigraphy of the basaltic tuff-ring of El Puig d’Adri and its phreatomagmatic deposits, including basaltic ignimbrites. After these geological stops, we will visit Caldes de Malavella, a beautiful village declared historical monument of national interest, with a great tradition in spas and thermal water springs since Roman Empire in time of Emperor Augustus, who called this village Aquae Calidae. Moreover, we can find Medieval architecture such as the walls of the old castle Caldes with 3 towers of s. XII and also modernist and neoclassical buildings in the old town of the village (http://www.femturisme.cat/en/villages/caldes-de-malavella). After lunch in Caldes de Malavella, the group will visit the open fossil excavation in lacustrine sediments of the Camp dels Ninots Pliocene maar crater located in the same village. During the morning of the second day, the group will visit the Montsacopa complex cinder cone that rises right in the heart of the city and is one of the five volcanoes that stand inside the city of Olot. This volcano exhibits a diversity of eruptive styles with strong evidence of vent migration controlled by tectonic features. After that, we will do a tour around the rootless volcanoes and tumuli lava field of Bosc de Tosca, with more than one hundred tossols (local name of rootless volcanoes) that have formed all along the lava flow emitted by the Puig Jordà volcano with an age of about 17,000-years old. After lunch in a popular restaurant in the region, the attendees will visit Sant Joan Les Fonts columnar-jointed lava flows. The last stop of the second day will be in the Quaternary Cairat maar volcano and their phreatomagmatic deposits. The last day of the field trip, the participants will enjoy the wonderful views and landscapes of the Garrotxa Volcanic Park and the Mediterranean coast from the Xenacs panoramic viewpoint. An important aspect of this field trip is that it will also include discussions about the relation between science and society taking into account that in this region volcanoes are present in many aspects of local society, as its cultural heritage, local history, architecture, or even in its excellent cuisine. The local people are aware of living among volcanoes and that they represent the most characteristic feature of their region, in an extent comparable or even superior to areas with more active volcanism.Peer Reviewe