Fluorescent Whitening Agents Research Articles

Novel Analysis of Recycled Pulp-Containing Paper, Including Fluorescent Whitening Agent:

Novel Analysis of Recycled Pulp-Containing Paper, Including Fluorescent Whitening Agent:

Putative C2H2 Transcription Factor AflZKS3 Regulates Aflatoxin and Pathogenicity in Aspergillus flavus.

Aflatoxin is a carcinogenic secondary metabolite that poses a serious threat to human and animal health. Some C2H2 transcription factors are associated with fungal growth and secondary metabolic regulation. In this study, we characterized the role of AflZKS3, a putative C2H2 transcription factor based on genome annotation, in the growth and aflatoxin biosynthesis of A. flavus and explored its possible mechanisms of action. Surprisingly, the protein was found to be located in the cytoplasm, and gene deletion in A. flavus resulted in defective growth and conidia formation, as well as increased sensitivity to the fluorescent brightener Calcofluor white, Congo red, NaCl, and sorbitol stress. Notably, the biosynthesis of aflatoxin B1 was completely inhibited in the ΔAflZKS3 deletion strain, and its ability to infect peanut and corn seeds was also reduced. RNA sequencing showed that differentially expressed genes in the ΔAflZKS3 strain compared with the control and complementation strains were mainly associated with growth, aflatoxin biosynthesis, and oxidative stress. Thus, AflZKS3 likely contributes to growth, cell development, and aflatoxin synthesis in A. flavus. These findings lay the foundation for a deeper understanding of the roles of C2H2 transcription factors in A. flavus and provide a potential biocontrol target for preventing aflatoxin contamination.

Lighting time analysis of water-based flexographic inks containing phosphorescent pigments

The research investigates the illumination time of four luminescent pigments (green, blue, violet, and orange) dedicated to security printing and other special effect covers. It involves printout preparation on paper bases with and without optical brighteners with nine k-bar applicators and flexographic water-based inks with three different pigment concentrations (5, 15, and 30%). The printouts assessment is in the range of wild ink film thickness concerning the time of illumination. Achieved results led to the modelling of these properties. The Zeiss SEM microscope presents the images of the pigments tested.The innovation in this research is to show the nature of luminescent pigments and inks and to demonstrate its application possibility. The mathematical models presented in this article can help to adjust the appropriate ink layer's thickness and pigment concentration to achieve the desired glow time.The article shows that the green pigment glows the longest, successively blue and violet. The changes in the glow time from the thickness of the layer look similar for green and blue, for violet only at the highest pigment concentration. In contrast, the orange differs significantly from the others and shines approx. 20 times as short as the green one. The article explains how the size of the pigment can affect its glow time and why the samples obtained on a substrate containing optical brighteners glow longer. The optical brighteners intensify the shining time for the longer light wavelengths of pigments, such as green and orange, than for the shorter ones – blue and violet. The influence of the substrate on the glow effect is less visible for higher pigment concentration or greater print layer thickness. Applying a luminescent pigment on a dark-coloured substrate diminishes the lighting effect and eliminates it on a black one.

A novel fluorescent probe with high sensitivity for sequential detection of CN− and Al3+ in highly aqueous medium and its applications in living cell bioimaging

Benzothiazole refers to a type of heteroaromatic compound constituted by electron rich nitrogen and sulphur atoms from molecular level, and presents powerful fluorescence in solutions, resulting its widely application in fluorescent whitening agents, fluorescent dyes and functional coordination. In this paper, we focused on designing and synthesizing a benzothiazole-functionalized naphthalimide fluorescent probe NIB for sequentially detecting CN− and Al3+ in DMSO/H2O (1:9, v/v) solution using these fluorescence properties of benzothiazole. When the fluorescent probe NIB interacts with CN−, the fluorescence of the probe is quenched, indicating that NIB can specifically respond to CN−. According to the anti-interference experiment, NIB possesses strong anti-interference ability toward CN−, and its detection limit of CN− is 6.31 × 10−7 M. Interestingly, the fluorescence of the NIB-CN− system was turned back on again by adding Al3+ ions which has good anti-interference performance against other cations. The lowest detection limit of NIB-CN− system for Al3+ is 2.85 × 10−6 M. After 10 cycles, NIB still has good sequential detection performance for CN− and Al3+, which can serve as a highly sensitive logic gate for the detection of CN− and Al3+, and the “On-Off-On” switches of this fluorescence can be observed under UV light megascopically. The mechanism of sequential detection of CN− and Al3+ was further discussed by experimental and theoretical methods. The detection mechanism is not the traditional coordination competition mechanism, but the sequential addition of CN− and Al3+ changes the aggregation mode of probe molecules in the system. In addition, the potential application of this probe was fully confirmed by the preparation of probe NIB test paper and the realization of sequential detection of CN− and Al3+ in living cells (HeLa).

Occurrence, potential sources, and risk assessment of pharmaceuticals and personal care products in atmospheric particulate matter in Hanoi, Vietnam.

Pharmaceutical and personal care products (PCPPs) were recently recognized as emerging pollutants due to their potential for adverse health and environmental impacts. One potential route of exposure, atmospheric particulate matter (APM), for polar PPCP chemicals has to date received limited attention. This study screened for 190 polar PPCP chemicals in outdoor APM samples collected from two locations in Hanoi, Vietnam, and predictions of source and potential effects on human health are presented. Day and night, as well as dry and rainy seasonal samples, were taken, and samples screened by LC-TOF, using sequential window acquisition and all theoretical fragment ion spectra method. Eleven PPCP chemicals were detected above the LOD and in more than one sample. The ∑11PPCP chemicals ranged from 0.61 to 21.9ngm-3 (median 2.07ngm-3), with between 2 and 6 compounds identified in individual samples (median 4). The ∑11PPCP chemicals collected near a heavy traffic area was greater than that in a populated residential zone. Night concentrations were significantly greater than day in both dry and rainy seasons (p < 0.05). Butyl methoxydibenzoylmethane, benzophenone-3, acetaminophen, cotinine, and fluorescent brightener 71 were detected in > 50% of samples. These are typically found in sunscreens, cosmetics, antipyretics, tobacco, and dyes. The DIair, hazard quotient (HQ), and hazard index (HI) for adults and children at sampling sites were estimated. The HQ for both adults and children were orders of magnitude less than the risk or were close to or whichever. APM does appear to be a potential additional secondary exposure source of PPCP chemicals to the environment and more work is needed to identify if sources are local or ubiquitous and if there is a greater health risk.

Butterfly Wing Color Pattern Modification Inducers May Act on Chitin in the Apical Extracellular Site: Implications in Morphogenic Signals for Color Pattern Determination.

Butterfly wing color patterns are modified by various treatments, such as temperature shock, injection of chemical inducers, and covering materials on pupal wing tissue. Their mechanisms of action have been enigmatic. Here, we investigated the mechanisms of color pattern modifications usingthe blue pansy butterfly Junoniaorithya. We hypothesized that these modification-inducing treatments act on the pupal cuticle or extracellular matrix (ECM). Mechanical load tests revealed that pupae treated with cold shock or chemical inducers were significantly less rigid, suggesting that these treatments made cuticle formation less efficient. A known chitin inhibitor, FB28 (fluorescent brightener 28), was discovered to efficiently induce modifications. Taking advantage of its fluorescent character, fluorescent signals from FB28 were observed in live pupae in vivo from the apical extracellular side and were concentrated at the pupal cuticle focal spots immediately above the eyespot organizing centers. It was shown that chemical modification inducers and covering materials worked additively. Taken together, various modification-inducing treatments likely act extracellularly on chitin or other polysaccharides to inhibit pupal cuticle formation or ECM function, which probably causes retardation of morphogenic signals. It is likely that an interactive ECM is required for morphogenic signals for color pattern determination to travel long distances.

Identification and trend analysis of organic cationic contaminants via non-target screening in suspended particulate matter of the German rivers Rhine and Saar

Non-target screening of suspended particulate matter (SPM), collected from the German rivers Rhine and Saar, was conducted with the goal of identifying organic, permanent cationic contaminants and of estimating their temporal trends over an extended period. Therefore, annual composite samples of SPM, provided by the German Environmental Specimen Bank, were extracted and analyzed with high resolution LC-QToF-MS/MS. To facilitate the identification of substances belonging to the class “permanent cations”, prioritization methods were applied utilizing the physicochemical properties of these compounds. These methods include both interactions of the analyte molecules with cation exchange resins and analyzing mass deviations when changing from non-deuterated to deuterated mobile phase solvents during LC-MS analysis. By applying both methods in a combined approach, 123 of the initially detected 2695 features were prioritized, corresponding to a 95% data reduction. This led to the identification of 22 permanent cationic species. The organic dyes Basic Yellow 28 and Fluorescent Brightener 363 as well as two quaternary ammonium compounds (QACs) were detected in environmental samples for the first time to best of or knowledge. The other compounds include additional QACs, as well as quaternary tri-phenylphosphonium compounds (QPC/TPP). In addition to identification, we determined temporal trends of all compounds over a period of 13 years and assessed their ecotoxicological relevance based on estimated concentrations. The two QACs oleyltrimethylammonium and eicosyltrimethylammonium show significant increasing trends in the Rhine SPM and maximum concentrations in the Saar SPM of about 900 and 1400 µg/kg, respectively. In the case of the dyes, constant trends have been observed at the end of the studied period, but also maximum concentrations of 400 µg/kg for Basic Yellow 28 in 2006 and 1000 µg/kg for Fluorescent Brightener 363 in 2015, potentially indicating a strong ecotoxicological risk.

The applicability of Calcofluor White (CWS) and Fluorescent Brightener (CFB) dyes for confocal laser microscopic analysis (CLSM) of various β-glucans in selected dairy products and water

The aim of this study was to determine the applicability of commonly used dyes (CWS and CFB) to stain different types of β-glucans in water and selected, most popular, dairy products for CLSM imaging analysis. Structurally different pure β-glucan preparations: curdlan-CU, oat β-glucan-OG and scleroglucan-SC were tested. Our study showed for the first time that CWS is a dye with a specific affinity for all analyzed β-glucans, while CFB is suitable for curdlan labeling only. Despite the technological processes, β-glucans structures in dairy products are similar to those in aqueous suspension forms; each of the β-glucans forms a different and characteristic structure, ranging from spindle-shaped and branched till granular. The presented results for the first time systematize the knowledge on CWS and CFB applicability in β-glucan CLSM staining and allow future researchers to correctly analyze simultaneously stained β-glucan, fat, and protein in a complex matrix as dairy products.

Switzerland: BASF – optical brighteners

Switzerland: BASF – optical brighteners

Effects of fire extinguishing agents on pyrolysis and explosion characteristics of optical brightener dust

As a widely used optical additive, optical brightener has a potential risk of dust explosion during production and utilization, which limits its further application. In this paper, the pyrolysis process and explosion characteristics of universal optical brightener OBA-184 dust were studied, and the inhibition effects of NH4H2PO4, NaHCO3, and aerosil (nano-silica) were compared using the Hartmann tube and the 20-L spherical explosion system. The results illustrate that OBA-184 dust is a substance with huge heat of decomposition. All three extinguishing agents can effectively moderate the ignition sensitivity and explosion severity. Among them, NH4H2PO4 has the best efficiency in suppressing explosion severity due to its excellent chemical inhibition effect. The complete inert ratio of NH4H2PO4 was about 60% lower than that of NaHCO3, while aerosil can not completely inert the OBA-184 dust at the inert ratio in the range studied. NaHCO3 can significantly reduce the ignition sensitivity of OBA-184 dust, and adding 60% NaHCO3 can reduce the dust to a low sensitivity level. Inerting is accomplished due to its low decomposition temperature and violent heat absorption rate; Aerosil is less effective than NH4H2PO4 and NaHCO3, which attributes to its poor physical heat absorption and weak chemical inhibition ability. The results of this paper provide a theoretical and practical basis for dust explosion prevention and control in the optical brightener industry.

Daytime radiative cooling capacity of nanoparticle on thermoplastic polyurethane (TPU) film

Radiative cooling, which does not entail any energy consumption, has received considerable attention as a promising, practical, and sustainable solution to heatwaves. This study investigated single layer nanoparticles–polymer films that reflected sunlight and emitted radiation through atmospheric windows. In this paper, the fundamental principles of Mie theory, the cooling power model, and the thermal balance model of metamaterial films were first introduced. Then, the influence of fabrication parameters (nanoparticle materials, mass fractions, and thicknesses) to the reflectivity in solar band was experimentally explained. An increase in the mass fraction enhanced the reflectivity corresponding to the stretching vibration regions of CH, NH, and OH, while an increase in the thickness improved the reflectivity at non-absorption bands. Laboratory measurements indicated that the combination of TiO2, a fluorescent brightener, and a far-infrared ceramic powder on 100 μm thermoplastic polyurethane film achieved excellent solar reflectivity of 92.2 % and infrared emissivity of 96.1 %. Experimental testing and Fluent simulation showed that the film achieved a substantial cooling capacity in both Beijing and Tianjin. Under a transparent atmospheric window, it exhibited a subambient temperature of 3.7 °C when the air temperature reached its peak. The maximum daytime and night-time subambient temperature were 13.4 °C and 14 °C respectively.

Recycled Plastic Content Quantified through Aggregation-Induced Emission.

The linearity of the plastics economy is wasteful and polluting. To encourage recycling and decrease diversion to landfill, new legislation within the EU and UK will tax single-use plastic products made with less than 30% recycled plastic. At present, quantitative determination of recycled content is elusive and existing methods are inconsistent. We present a fluorescence-based analytical technique to determine recycled content in plastic and (single use) packaging. Bathochromic shifts resulting from aggregation of the fluorescent brightener 4,4′-bis(2-benzoxazolyl) stilbene (BBS) in three commodity plastics [high-density polyethylene, polypropylene, and poly(ethylene terephthalate)] at loadings ≤0.5 wt % were used to systematically quantify simulated recycled contents as low as 10 wt %. Linear correlations were found between recycled content and three fluorescence-based properties: emission, lifetime, and resulting color. We demonstrate how this multi-branched verification system is completely independent of sample dimensions and processing conditions, has a negligible effect on polymer properties, and is inexpensive and highly compatible with existing recycling infrastructure.

Spatial Heterogeneity of CDOM, Optical Brighteners, and Oils in Mesohaline Tidal Creeks Using Self-Organizing Maps

Shallow tidal creek systems or triblets are often overlooked when documenting and measuring the spatial extent of pollutants of emerging concern despite much of the population living in and around these areas. An innovative in situ fluorometric instrument coupled with a Self-Organi21zing Map was utilized in Chesapeake Bay’s mesohaline tidal creek system to analyze CDOM, dissolved oxygen, optical brighteners, and oils. The in situ fluorometer proved helpful as a rapid reconnaissance tool complementing the investigation when attached to a CTD instrument. This baseline research showed that CDOM follows non-conservative properties in spring and more conservative behavior in the fall. The results show that the Self-Organizing Map method is a suitable alternative to traditional statistical techniques and may be better at finding key patterns that might otherwise have been obscured by high variability. For example, oils revealed a pattern with residual runoff from highways or boating, while optical brighteners displayed a pattern consistent with septic systems. Optical brighteners also revealed lag effects after the passing of heavy rainfall and were consistent with the lab effect of turbidity. The study also reveals that CDOM is the dominant control on light penetration, one of the limiting factors on underwater grass growth. The results also suggest that CDOM should not be overlooked when measuring the effects of restoration in these systems and should be implemented in regular monitoring and TMDLs.

Phenotypic Plasticity of the Mimetic Swallowtail Butterfly Papilio polytes: Color Pattern Modifications and Their Implications in Mimicry Evolution.

Butterfly wing color patterns are sensitive to environmental stress, such as temperature shock, and this phenotypic plasticity plays an important role in color pattern evolution. However, the potential contributions of phenotypic plasticity to mimicry evolution have not been evaluated. Here, we focused on the swallowtail butterfly Papilio polytes, which has nonmimetic and mimetic forms in females, to examine its plastic phenotypes. In the nonmimetic form, medial white spots and submarginal reddish spots in the ventral hindwings were enlarged by cold shock but were mostly reduced in size by heat shock. These temperature-shock-induced color pattern modifications were partly similar to mimetic color patterns, and nonmimetic females were more sensitive than males and mimetic females. Unexpectedly, injection of tungstate, a known modification inducer in nymphalid and lycaenid butterflies, did not induce any modification, but fluorescent brightener 28, another inducer discovered recently, induced unique modifications. These results suggest that phenotypic plasticity in nonmimetic females might have provided a basis of natural selection for mimetic color patterns during evolution.

Identification of Fluorescent Brighteners as Another Emerging Class of Abundant, Ubiquitous Pollutants in the Indoor Environment.

Fluorescent brighteners (FBs) are extensively used as important chemical additives in multiple industrial fields worldwide. The history of the use of global FBs spans over 60 years, but knowledge on their environmental occurrence and risks remains largely unknown. Here, we screened indoor dust and hand wipes from South China for a broad suite of 17 emerging FBs using a new comprehensive analytical method. All 17 FBs were detected in the indoor environment for the first time, most of them having been rarely investigated or never reported in prior environmental studies. Ionic FBs were found to be more abundant than nonionic ones. The median total concentrations of the 17 detectable FBs reached 11,000 ng/g in indoor dust and 2640 ng/m2 in hand wipes, comparable to or higher than those of well-known indoor pollutants. Human exposure assessment indicated that hand-to-mouth contact is a significant pathway for exposure to FBs, with a comparable contribution to that of dust ingestion. Most of the newly identified FBs are predicted to have persistent, bioaccumulative, or toxic properties. Our work demonstrates that FBs are another class of highly abundant, hazardous, and ubiquitous indoor pollutants that have been overlooked for decades and points to an emerging concern.

Application of an improved hollow fiber liquid phase microextraction technique coupled to LC-MS/MS to studying migration of fluorescent whitening agents from plastic food contact materials

In this paper, a new hollow fiber liquid-phase microextraction method was developed to improve the extraction of five fluorescent whitening agents that migrated from plastics food contact materials. Influencing factors, such as the types of membrane, the extraction solvent, the stirring speed, the addition of salt ion, and extraction time, were investigated in detail. Under the optimal conditions, high enrichment factors (71–205) can be obtained with 15 μL extraction solvent. The new method is advantageous; the polypropylene hollow fiber membrane modified by sepiolite nanoparticles had excellent solvent binding force and mass transfer effect compared with the conventional extraction technique. The extracts were analyzed by high performance liquid chromatography–tandem mass spectrometry, the limits of detection were 0.3 or 0.9 ng kg−1 with good correlation coefficients (r 2 ≥ 0.9940) for the five fluorescent whitening agents. The intra-day and inter-day recoveries ranged between 82.6% and 112%, with a relative standard deviation of less than 12%. The established method was successfully applied to the analysis of fluorescent whitening agent migration from four types of plastic food contact materials immersed in three food simulants.

Fluorescent Microscopy-Based Detection of Chitin in Intact Drosophila melanogaster.

Chitin is the major scaffolding component of the insect cuticle. Ultrastructural analyses revealed that chitin adopts a quasi-crystalline structure building sheets of parallel running microfibrils. These sheets called laminae are stacked either helicoidally or with a preferred orientation of the microfibrils. Precise control of chitin synthesis is mandatory to ensure the correct chitin assembly and in turn proper function of cuticular structures. Thus, evaluation of chitin-metabolism deficient phenotypes is a key to our understanding of the function of the proteins and enzymes involved in cuticle architecture and more generally in cuticle biology in insects. Usually, these phenotypes have been assessed using electron microscopy, which is time-consuming and labor intensive. This stresses the need for rapid and straightforward histological methods to visualize chitin at the whole tissue level. Here, we propose a simple method of chitin staining using the common polysaccharide marker Fluorescent brightener 28 (FB28) in whole-mount Drosophila melanogaster. To overcome the physical barrier of FB28 penetration into the cuticle, staining is performed at 65°C without affecting intactness. We quantify FB28 fluorescence in three functionally different cuticular structures namely wings, dorsal abdomens and forelegs by fluorescence microscopy. We find that, as expected, cuticle pigmentation may interfere with FB28 staining. Down-regulation of critical genes involved in chitin metabolism, including those coding for chitin synthase or chitinases, show that FB28 fluorescence reflects chitin content in these organs. We think that this simple method could be easily applied to a large variety of intact insects.

Synthesis of biscoumarin bifunctional reactive fluorescent whitening agents and their application on nylon-6 fabric

Two new bifunctional reactive fluorescent whiting agents based on joining two coumarin moieties together through triazinyle-stilbene fluorescent moiety have been successfully synthesized, applied on nylon-6 fabrics and then characterized by NMR and elemental analysis. Spectral properties, such as absorption and emission spectra in solution and on fabrics are investigated. The application of all the prepared compounds as fluorescence [fluorescence whiting agents (FWAs)] and their whiteness as well as light fastness properties on nylon-6 fabric have been compared with monofunctional agent. Despite the fact that the FWAs, containing either mono or bis methyl coumarin derivatives, show better whiteness properties than the FWA containing phenyl coumarin derivative, the later compound shows higher light fastness (excellent).

The effect of mixtures of Bacillus thuringiensis-based insecticide and multiple nucleopolyhedrovirus of Lymantria dispar L. in combination with an optical brightener on L. dispar larvae

The effect of mixtures of Bacillus thuringiensis-based insecticide and multiple nucleopolyhedrovirus of Lymantria dispar L. in combination with an optical brightener on L. dispar larvae

Efficacy of HearNPV formulations against &lt;i&gt;Helicoverpa armigera&lt;/i&gt; at different sunlight exposure period

&lt;p&gt;Experiment was conducted at Department of Entomology, Dr. Panjabrao Deshmukh Krishi Vidyapeeth, Akola during 2011- 2013 to see the effect of natural sunlight (UV) on HearNPV formulation. Experiment was laid out in Completely Randomized Block Design replicated thrice. The aqueous and dry form of HearNPV formulations were prepared by using additives viz. Tinopal an optical brightener and silver nano particle and evaluated their capability to protect NPVs from Ultra Violet rays. HearNPV formulation were sprayed uniformly on the potted chickpea plants during noon hours. Twigs were collected at thirty minutes, One hour, One and half hours and two hours after spraying and kept in petriplates. The laboratory reared second instar larvae of &lt;em&gt;H. armigera&lt;/em&gt; were released on each treated twig. Larval mortality was recorded at 4, 7 and 10 days after treatment. An aqueous form of HearNPV formulation, HearNPV + Silver Nano Particles @ 8 ?l /ml of HearNPV + Tinopal 1% + Sucrose 1% (T1) recorded 83.04% larval mortality at ten days after spraying which was at par with HearNPV alone unirradiated (84.21 % larval mortality) when exposed to sunlight up to one hour. Among the lyophilized form of formulations, HearNPV + Silver Nano Particles @ 8?l/ml of HearNPV + Tinopal 1% + Sucrose1% (T6) when exposed to sunlight up to one hour recorded 84.80% larval mortality at ten days after spraying which was at par with which was at par with HearNPV alone unirradiated (T12) (85.38% larval mortality) and higher than HearNPV alone irradiated. Both aqueous and lyophilized form of HearNPV showed decreasing larval mortality as compared to HearNPV alone unirradiated when exposed to sunlight up to one and half and two hours. Lyophilized HearNPV formulations recorded higher larval mortality as compared to aqueous form of HearNPV formulations at all sunlight exposure period.&lt;/p&gt;