Process Safety Assessment of the Iron-Catalyzed Direct Olefin Diazidation for the Expedient Synthesis of Vicinal Primary Diamines

We report herein a process safety assessment of the iron-catalyzed direct olefin diazidation for the preparation of a broad range of synthetically valuable vicinal primary diamines. Differential scanning calorimetry analysis of the corresponding reagents, intermediates, and a list of representative diazide/diaminium salt products revealed that all of them are thermal stable at the reaction temperature. The drop weight test of the diazides suggested that they are moderately impact-sensitive. Guided by this assessment, an optimized olefin diazidation/diamination procedure has been developed which allows for the gram-scale diaminium salt synthesis without purification of the diazide intermediate

Accelerated solvent extraction by using an ‘in-line’ clean-up approach for multiresidue analysis of pesticides in organic honey

<p>The worldwide loss of honeybee colonies may be due to their exposure to several contaminants (i.e., pesticides); such contamination may also have impacts on consumers’ health. Therefore, it is essential to develop quick and new methods to detect several pesticide residues in honey samples. In this study, the effectiveness of accelerated solvent extraction (ASE) was compared with QuEChERS methods for the analysis of 53 pesticides in organic honey by gas chromatography-triple quadrupole mass spectrometry. Two simple and rapid ASE methods with ‘in-line’ clean-up were optimised and then compared with QuEChERS. Hexane–ethyl acetate (Hex:EtAc) and Florisil were chosen as extraction solvent and retainer for the first ASE method respectively; acetonitrile and a primary–secondary amine phase (ACN-PSA) were selected for the second ASE method. The methods were validated according to the European Union SANTE/11945/2015 guidelines. The validation parameters showed that QuEChERS and ASE with PSA as retainer had better repeatability than ASE with Hex:EtAc and Florisil. In particular, QuEChERS and ASE (ACN-PSA) showed good recovery, according to the SANTE criteria, for the majority of investigated pesticides. Conversely, when ASE with Hex:EtAc and Florisil was used as the retainer, several compounds showed recoveries lower than the acceptable value of 70%. The ASE in-line method was finally applied to evaluate pesticide concentration in organic honey samples.</p

Endogenous level of acetic acid in yellowfin tuna (<i>Thunnus albacares</i>): a pilot study about a possible controversy on its residue nature

<p>A method based on headspace solid-phase microextraction (HS-SPME) followed by GC-MS analysis was developed for the determination of underivatised acetic acid in fresh tuna fish muscle. Parameters such as the fibre selected and the extraction time and temperature were optimised and the linearity, detection limits and precision of the whole analytical procedure were assessed. The method was then applied to determine the acetic acid concentration in fresh yellowfin tuna muscles (<i>Thunnus albacares</i>) in order to evaluate the endogenous level and its variations during the shelf life under different storage conditions. A qualitative comparison was also made with variations in histamine levels to evaluate the possibility of the joint monitoring of acetic acid and histamine to identify fish stored in poor conditions. The caudal area always had a lower content of acetic acid than the ventral area, independent of the storage time and temperature. A difference was found between the 6- and 3-day time points and day 0 at a storage temperature of 8°C and between the 6-day time point and day 0 at a storage temperature of 0°C, independent of the anatomical area of the sampled tissue. The evaluation of acetic acid could represent an important approach in the field of food safety to detect the illicit use of acetic acid as an antibacterial preservative treatment or to eliminate the unpleasant smell of trimethylamine.</p

Clinical efficacy and pharmacokinetics of meloxicam in Mediterranean buffalo calves (<i>Bubalus bubalis</i>)

<div><p>The aims of the investigation were to establish for the first time (i) clinical efficacy and (ii) pharmacokinetic profile of meloxicam intravenously (IV) administered in male Mediterranean buffalo calves after surgical orchiectomy. The study was performed on 10 healthy buffalo calves, between 4 and 5 months old and between 127 and 135 kg of body weight (b.w.). An IV injection of 0.5 mg/kg b.w. of meloxicam was administered in six calves (treated group, TG) immediately after surgery; the other four animals were used as untreated control group (CG). The clinical efficacy of meloxicam was evaluated pre- and post-surgery by monitoring respiratory rate (RR), heart rate (HR), rectal temperature (T°C), serum cortisol levels (SCL) and pain score (PS). Significant inter-groups differences were detected at sampling times (T): 4 hour (h) for RR (<i>P<</i>0.05), at T1-4-6-8 h for PS (<i>P<</i>0.05) and at T4-6-8 h for SCL (<i>P</i> < 0.0001). Regarding the mean intra-group values observed pre (T0) and post-surgery (from T15 min to T72 h), significant difference between the groups were found for RR (<i>P<</i>0.01), PS and SCL (<i>P<</i>0.05). The pharmacokinetic profile was best fitted by a two-compartmental model and characterized by a fast distribution half-life and slow elimination half-life (0.09 ± 0.06 h and 21.51 ± 6.4 h, respectively) and meloxicam mean concentrations at 96 h was of 0.18 ± 0.14 μg/mL. The volume of distribution and clearance values were quite low, but reasonably homogenous among individuals (V_dss 142.31 ± 55.08 mL/kg and Cl_B 4.38 ± 0.95 mL/kg/h, respectively). The IV administration of meloxicam in buffalo calves shows encouraging effects represented by significant and prolonged analgesic effects, significant reduction of SCL as well as similar pharmacokinetic profile to bovine calves.</p></div

Pre- and post- orchiectomy UNESP-Botucatu unidimensional pain scale used at each sampling time.

<p>Pre- and post- orchiectomy UNESP-Botucatu unidimensional pain scale used at each sampling time.</p

Mean serum cortisol levels pre- (T0) and post- orchiectomy (from T15m to T72h).

<p>TG = treated groups; CG = control group; min = minutes; h = hours;T = time; ^a,b <i>P <</i> 0.0001.</p