Protonation of Patented Blue V in aqueous solutions: theoretical and experimental studies

Simultaneous determination of five triarylmethane colorants in syrup by applying multivariate curve resolution to second-derivative visible absorption spectra

A method for the simultaneous determination of five triarylmethane colorants (brilliant blue FCF, patent blue V, patent blue VF, fast green FCF, and green S) in syrup samples was proposed by applying multivariate curve resolution to second-derivative visible absorption spectra in citrate and carbonate buffer solutions. Even for heavily overlapping spectra, adopting second-derivative spectra and multiway analysis in citrate and carbonate buffer solutions enhanced specificity for the analytes and achieved prediction performance with a coefficient of determination (R²) > 0.90, root mean square error of prediction (RMSEP) < 0.20 mg/L, and limit of detection (LOD) < 0.50 mg/L for all five analytes. The basis set expansion method succeeded in a reasonable estimation of the second-derivative spectra with the interferant. For commercial syrup samples, the present method predicted results without significant differences compared to the results measured using liquid chromatography-mass spectrometry. The proposed method provides a rapid alternative to liquid chromatography techniques for the quantification of multiple colorants in food samples.

Robust rapid-setting antibacterial liquid bandages

Bandaging is a steadfast but time-consuming component of wound care with limited technical advancements to date. Bandages must be changed and infection risk managed. Rapid-set liquid bandages are efficient alternatives but lack durability or inherent infection control. We show here that antibacterial zinc (Zn) and copper (Cu) species greatly enhance the barrier properties of the natural, waterproof, bio-adhesive polymer, shellac. The material demonstrated marked antibacterial contact properties and, in ex-vivo studies, effectively locked-in pre-applied therapeutics. When challenged in vivo with the polybacterial bovine wound infection 'digital dermatitis', Zn/Cu-shellac adhered rapidly and robustly over pre-applied antibiotic. The bandage self-degraded, appropriately, over 7 days despite extreme conditions (faecal slurry). Treatment was well-tolerated and clinical improvement was observed in animal mobility. This new class of bandage has promise for challenging topical situations in humans and other animals, especially away from controlled, sterile clinical settings where wounds urgently require protection from environmental and bacterial contamination.

[Nomenclature and Identification Method of Non-Permitted Dyes of Patent Blue Group]

Violation of the Food Sanitation Act regarding detection of Patent Blue V, which is one of the non-permitted dyes for food in Japan, in imported food occurs every year. With respect to the identification of dyes of Patent Blue group, in some cases, each dye has several different names, and in other cases, different dyes have the same name. Thus, there is a risk that the detected dye is misidentified with other dyes of Patent Blue group. In this study, nine commercial available dyes of Patent Blue group, including a reagent with unclear product information, were analyzed by TLC, HPLC and LC-MS/MS. The result showed that with all three methods, the dyes could be clearly identified into one of four types of blue dyes, i.e. Patent Blue V, Azure Blue VX, Isosulfan Blue and Alphazurine A. Unification of nomenclature would reduce the risk of misidentification of dyes of Patent Blue group.