Remifentanil (4-methoxycarbonyl-4-[(1-oxopropyl)phenylamino]-1-piperidinepropionic acid methyl ester) is a mu-opioid receptor agonist with considerable abuse potential in racing horses. The identification of its major equine urinary metabolite, 4-methoxycarbonyl-4-[(1-oxopropyl)phenylamino]-1-piperidinepropionic+ ++ acid, an ester hydrolysis product of remifentanil is reported. Administration of remifentanil HCl (5 mg, intravenous) produced clear-cut locomotor responses, establishing the clinical efficacy of this dose. ELISA analysis of postadministration urine samples readily detected fentanyl equivalents in these samples. Mass spectrometric analysis, using solid-phase extraction and trimethylsilyl (TMS) derivatization, showed the urine samples contained parent remifentanil in low concentrations, peaking at 1 h. More significantly, a major peak was identified as representing 4-methoxycarbonyl-4-[(1-oxopropyl)phenylamino]-1-piperidinepropionic+ ++ acid, arising from ester hydrolysis of remifentanil. This metabolite reached its maximal urinary concentrations at 1 h and was present at up to 10-fold greater concentrations than parent remifentanil. Base hydrolysis of remifentanil yielded a carboxylic acid with the same mass spectral characteristics as those of the equine metabolite. In summary, these data indicate that remifentanil administration results in the appearance of readily detectable amounts of 4-methoxycarbonyl-4-[(1-oxopropyl)phenylamino]-1-piperidinepropionic+ ++ acid in urine. On this basis, screening and confirmation tests for this equine urinary metabolite should be optimized for forensic control of remifentanil.

online trends. Both methods were compared to the expert opinion coinciding with 84 and 85 %, respectively.

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Liquid food products stick to solid surfaces. This problem occurs in all supply chain steps from production to recycling. Although the basic problem has been known for a long time, the parameters influencing the interfacial adhesion have not been clarified yet. Here, two methods (product depletion test and tack test) to evaluate the adhesion of highly viscous liquids to solid surfaces have been developed. The product depletion test allows the assessment of the residue amounts and covered surface areas during the gravity-driven flow on an inclined plane. The tack test is conducted by filling the gap between two parallelly mounted, horizontally oriented plates with a liquid product and measuring the normal force while separating the plates by pulling off the upper plate under defined conditions. The influence of the experimental parameters on the maximum normal force (F max ) could be shown. While the correlation between the pull off velocity of the upper plate and F max follows a power law, the dependency between the gap size and F max follows an exponential function. Although no significant correlation between F max or the work of adhesion (W a ) and the solid's properties could be identified, a correlation between F max and W a was observed. As shown by product depletion with ketchup, although the surface coverage is only slightly influenced by the packaging material, the opposite is the case for the covered surface area which, therefore, determines the residue amounts. For some coated samples a large residue reduction was observed.

Summary The turbidity potentials of long‐chain fatty acids as well as gelatinised starch were investigated in synthetic lautering wort to determine their contribution to turbidity according to concentration. Synthetic wort proved to be a standardised and reproducible model solution. Concentration series of gelatinised starch and single long‐chain fatty acids as pure substances showed high correlations between concentrations and turbidity levels of turbidity 11° and turbidity 90° measurements. Gelatinised barley starch has the turbidity potential of 0.04 EBC/(mg L−1) on turbidity 11° levels. Regarding long‐chain fatty acids, saturated fatty acids showed distinctly higher turbidity potentials on turbidity 11° (≥0.32 EBC/(mg L−1) and turbidity 90° (≥0.15 EBC/(mg L−1) than unsaturated fatty acids. The turbidity potential of the saturated fatty acids corresponded with their chain lengths, with stearic acid (18:0) showing the highest turbidity potential. However, the impact on turbidity is primarily determined by concentration and not by turbidity potential.