Procjena pouzdanosti uređaja za mjerenje koncentracije etanola u izdahnutom zraku usporedbom s koncentracijom etanola u krvi

The main goal of this study was to determine the reliability of hand-held breath alcohol analysers currently approved for roadside screening of traffic offenders. The first part of the study included a retrospective data analysis of 714 offence records collected in 2011. Blood alcohol concentrations (BAC) obtained from the offenders 0-303 min after the police had screened them for breath alcohol concentration (BrAC) were back-calculated (cBAC) to assess the accuracy of breathalyser screening. All participants were in the alcohol elimination phase, and our analyses did not reveal any significant differences between cBAC and BrAC. To verify our findings, we performed a controlled drinking study that involved 63 healthy volunteers who consumed alcoholic beverages to simulate real drinking conditions. Immediately after alcohol consumption, BrAC was determined with a Dräger breath alcohol analyser model 6810, and 29 participants gave blood and urine sample for concomitant BAC analysis one hour later. BAC and urine alcohol concentrations were determined with headspace gas chromatography. Again, we found no significant differences between BrAC and BAC. These results confirmed the high reliability of breath alcohol analysers for measuring BrAC as long as police officers perform the measurements according to the manufacturer’s instructions.Cilj ovog istraživanja bio je utvrditi pouzdanost alkometara kojima se trenutačno koristi hrvatska policija. Prvi dio istraživanja obuhvatio je retrospektivnu analizu 714 podataka prikupljenih tijekom 2011. godine. Uzorci krvi za određivanje koncentracija etanola u krvi (BAC) prikupljeni su najkasnije 303 minute nakon mjerenja koncentracije etanola u izdahu (BrAC) te su preračunati na vrijeme mjerenja BrAC (cBAC) kako bi se procijenila preciznost alkometara. Svi sudionici bili su u fazi eliminacije etanola, a naše analize nisu otkrile statistički značajne razlike između cBAC-a i BrAC-a. Da bismo potvrdili nalaz, proveli smo drugi dio istraživanja na uzorku od 63 zdrava dobrovoljca koji su konzumirali alkoholna pića. Netom nakon konzumacije alkohola BrAC je određen Drägerovim alkometrom marke 6810, a 29 sudionika dalo je uzorak krvi i urina za istu analizu sat vremena poslije. BAC i koncentracije alkohola u mokraći određeni su plinskom kromatografijom (HS-GC-FID). Ni u ovom istraživanju nismo pronašli statistički značajnu razliku između BrAC-a i BAC-a. Ovi rezultati potvrdili su visoku pouzdanost alkometara koji mjere BrAC, pod uvjetom da policijski službenici obavljaju mjerenja prema uputama proizvođača

The Effect of Tribomechanical Micronization and Activation on Rheological, Thermophysical, and Some Physical Properties of Tapioca Starch

The aim of this research was to investigate the effect of tribomechanical treatments on rheological, thermophysical, and some physical properties of tapioca starch. Samples of tapioca starch were treated using laboratory equipment for tribomechanical micronization and activation (TMA equipment). Before and after the TMA treatment, analysis of the particle size and particle size distribution was carried out, in addition to scanning electron micrography in tapioca starch. Scanning electron micrography showed that tribomechanical processing of tapioca starch resulted in breaking accumulations of starch granules in the form of granules. Pasting parameters have shown that maximal viscosities of model starch suspension have been decreasing after tribomechanical treatment. On the basis of gelatinization curves, it can be concluded that there are changes in the gelatinization point after treatment, and there is decrease in enthalpy of gelatinization for model suspension. After tribomechanical treatment, changes in physical properties of starch suspensions were determined, as well as specific swelling capacity, solubility index, and turbidity of tapioca starch suspensions