Search

To rapidly determine 9 biogenic amines including spermine, spermidine, putrescine, cadaverine, histamine, tryptamine, octopamine, tyramine and β-phenethylamine in aquatic products, the ultra high-performance liquid chromatography-tandem mass spectrometry method was established with Larimichthys polyactis using as matrix sample, and mobile phase and extract solvents were optimized. Matrix sample was extracted by 0.1% trichloroacetic acid (TCA) in duplicate, the supernatant was combined and filtered by 0.22 μm PTFE filters, and separated by HSS T3 column in 4 min. The mobile phase A was acetonitrile containing 0.1% formic acid, while mobile phase B was 10 mmol/L ammonium formate containing 0.2% formic acid. Nine biogenic amines were divided into three groups based on their different response intensity, with a concentration range of 1 to 40 ng/mL (tyramine and β-phenethylamine), 5 to 200 ng/mL (putrescine, cadaverine, histamine, tryptamine and octopamine), and 25 to 1000 ng/mL (spermine and spermidine). Their method quantification limits (LOQs) were 0.01, 0.05 and 0.25 mg/kg, respectively. The recovery rate of low, medium and high concentrations was 81.7%~111.2%, 80.0%~110.3% and 80.0%~99.0%, respectively, with the corresponding degree of precision (n=6) of 1.7%~7.3%, 1.3%~9.1% and 0.7%~4.6%. This method is simple, fast and with good sensitivity, recovery and precision, which is suitable for the determination of biogenic amines in Larimichthys polyactis.

Objectives Many factors should be taken into consideration in the selection of a fin stabilizer for a polar cruise ship, such as environmental adaptation and device performance, and it should not be chosen via subjective judgment. To this end, a comprehensive fin stabilizer selection and evaluation method based on a combined weighting-TOPSIS (technique for order preference by similarity to ideal solution) method is proposed. Methods The selection principle of a fin stabilizer for a polar cruise ship with a gross tonnage of 8 035 is confirmed according to the PC6 guidelines for polar class ships, and the initial area of the fin stabilizer is calculated using the experimental mathematical model. Three design schemes are put forward for the fin stabilizer. A selection and evaluation index system is built by consulting experts, including five primary indexes and fourteen secondary indexes. The weights of the indexes are determined using the analytic hierarchy process (AHP) and entropy weight method (EWM), and the TOPSIS method is introduced to calculate the degree of closeness between the alternative and ideal solutions. Results According to the ranking results, Design Scheme 1 (Aquarius A100 fin stabilizer) is selected as the optimal fin stabilizer for meeting the decision-makers' requirements. Conclusions The method proposed in this study has valuable guiding significance for the selection of fin stabilizers for polar cruise ships by reducing the blindness of the shipbuilders and decision-makers.