Oxidative Bleaching Research Articles

Evaluation of Anti-oxidant Activity of Different Extracts of Plumbago zeylanica Linn. & Development of Chromatographic Fingerprint of Chloroform Extracts.

The aim of the present investigation is to Evaluation of Anti-oxidant Activity of Different Extracts of Plumbago zeylanica Linn. & Development of Chromatographic Fingerprint of Chloroform Extracts. The roots of Plumbago zeylanica Linn. were purchased from the local market. The roots were taxonomically identified by Senior Scientist at KNK college of Horticulture. Accurately weighed quantity of roots of Plumbago zeylanica Linn. were extracted using petroleum ether (only for removal of fats and lipids), chloroform, methanol, butanol and finally water by soxhlet apparatus for 72 h. Qualitative chemical tests of chloroform, methanol, butanol and water extracts were subjected to various chemical tests to detect various phytoconstituents. β-carotene oxidative bleaching in β-caroten/linoleic acid mixture with and without the addition of different extract of plant. DPPH free radical scavenging activity of the test solutions was determined using DPPH photometric method. Anisaldehyde sulphuric acid and vanillin sulphuric acid and heated at 1150 C for 5 minutes. Solvent systems; n-hexane: ethyl acetate, 7:3 were found to be most satisfactory solvent system for chloroform extracts for root respectively. Vitamin E as standard was utilized in this measure and 84% hindrance was viewed as at 30 minutes. Chloroform separate likewise showed 70% restraint at 30 minutes which was decreased to 45% at the hour of 120 minutes. Hydroxyl revolutionary ability to rummage determined as IC50 from the trial information and it uncovers that chloroform, methanol, butanol and water removes have IC50 upsides of 46 μg/mL, 100μg/mL, 200 μg/mL and 150μg/mL, individually. DPPH scavenging capacity determined as IC50 and it shows that chloroform separate has IC50 of 36 μg/mL followed by ascorbic corrosive (3.1μg/mL), gallic corrosive (3.4μg/mL), methanol (41μg/mL), butanolic (46μg/mL) and water (44μg/mL) extricates. The present findings are momentous for the development of alternative, inexpensive and perhaps safer strategies for the handling of diseases.

The Effect of Oxidative Bleaching Using Chlorine Oxoacid Agents on the Characteristics of Cellulose Fibers and Hydrogel Films of Sugarcane Bagasse

The Effect of Oxidative Bleaching Using Chlorine Oxoacid Agents on the Characteristics of Cellulose Fibers and Hydrogel Films of Sugarcane Bagasse

Photosymbiosis reduces the environmental stress response under a heat challenge in a facultatively symbiotic coral

The symbiosis between corals and dinoflagellates of the family Symbiodiniaceae is sensitive to environmental stress. The oxidative bleaching hypothesis posits that extreme temperatures lead to accumulation of photobiont-derived reactive oxygen species ROS, which exacerbates the coral environmental stress response (ESR). To understand how photosymbiosis modulates coral ESRs, these responses must be explored in hosts in and out of symbiosis. We leveraged the facultatively symbiotic coral Astrangia poculata, which offers an opportunity to uncouple the ESR across its two symbiotic phenotypes (brown, white). Colonies of both symbiotic phenotypes were exposed to three temperature treatments for 15 days: (i) control (static 18 °C), (ii) heat challenge (increasing from 18 to 30 °C), and (iii) cold challenge (decreasing from 18 to 4 °C) after which host gene expression was profiled. Cold challenged corals elicited widespread differential expression, however, there were no differences between symbiotic phenotypes. In contrast, brown colonies exhibited greater gene expression plasticity under heat challenge, including enrichment of cell cycle pathways involved in controlling photobiont growth. While this plasticity was greater, the genes driving this plasticity were not associated with an amplified environmental stress response (ESR) and instead showed patterns of a dampened ESR under heat challenge. This provides nuance to the oxidative bleaching hypothesis and suggests that, at least during the early onset of bleaching, photobionts reduce the host’s ESR under elevated temperatures in A. poculata.

AN EFFECTIVE RESOURCE-SAVING OPTION IN THE SPHERE OF WOOD PROCESSING AND ITS PROCESSING IN THE PULP AND PAPER INDUSTRY

The possibility and expediency of obtaining and bleaching sulfite pulp from young small-sized spruce wood from thinning (thinning) fellings was studied in comparison with ripe wood. In the process of thinning, a significant amount of young small-sized wood is formed, which can serve as a significant reserve of wood raw materials for the production of pulp and paper.
 Sulfite pulping from young and ripe spruce wood obtained two samples of pulp of different degrees of penetration.
 Comparative pulp bleachings were carried out according to the traditional economical but effective D/C-EG-G-D-A scheme; For comparison, pulp samples from ripe and young spruce wood were bleached according to the modern ecological scheme Pa-E-Ch1-E-Ch2-A (ECF technology). 
 It is shown that young small-sized spruce wood is delignified by sulfite cooking solution without difficulty, but somewhat more slowly than ripe wood.
 Sulfite spruce pulp obtained from thinnings is easier to grind and bleach, has higher mechanical strength than from ripe wood. Bleached pulp was obtained from young thin spruce wood by bleaching according to the scheme D/C–EG –G–D–A of pulp from young thin spruce wood, which in all quality indicators meets the standards for grade AK-II (GOST 3914), which is used mainly in the production of "cultural" grades of paper (written and printed). Comparative bleaching of pulp of approximately the same degree of penetration from ripe and young wood using ECF technology using only two oxidative bleaching agents (hydrogen peroxide and chlorine dioxide) significantly increases the efficiency of pulp bleaching in all quality indicators, but the cost of bleaching, in modern conditions, may be will be slightly higher than in the traditional scheme.

Bleaching cotton in textile conservation: a closer look using atomic force microscopy

Aqueous bleaching may be used in textile conservation to improve the appearance of historic and culturally significant textiles. It is generally accepted amongst conservators that bleaching imparts damage. The aim of this research is to characterise the condition of cotton fibre's surface pre- and post-bleaching using atomic force microscopy (AFM). Unprocessed cotton calico (‘raw’ cotton), scoured cotton, and a historic cotton dress shirt (circa. 1920) were bleached using three separate methods: NaBH4 for 15 min; H2O2/NaBO3 for 1 h; and H2O2/NaBO3 buffered to pH 8.4 for 1 h. AFM was used in tapping-mode to obtain height, amplitude, and phase images. AFM imaging was able to distinguish between the cuticle, primary walls, and secondary walls of the cotton fibres. The data shows that bleaching has the effect of softening and removing individual layers of the cotton structure. Unprocessed cotton calico and scoured cotton fared better against the impact of bleaching. This was in stark contrast to the historic shirt where the already damaged surface of cotton fibres underwent further degradation using both oxidative and reductive bleaching. In general, reductive bleaching was more aggressive on the fibre surface compared to oxidative bleaching. The use of AFM provides further evidence of the physical effects of bleaching on historic textiles, and cotton textiles more broadly, and it has the potential to influence the conservator’s decision-making.

Cellulose Microfibers Isolated from Yucca Leaves: Structural, Chemical, and Thermal Properties

ABSTRACT The present study addressed the isolation of cellulose microfibers (CMF) from Yucca leaves using chemical treatments. This study was conducted in three stages, namely, two stages of alkaline treatments (NaOH 3%), and a single stage of bleaching treatment (H2O2 6%). The resulting microfibers were characterized using Scanning Electron Microscope (SEM), X-Ray diffraction (XRD), Fourier Transform Infra-red (FTIR), and Thermogravimetric Analysis (TGA). Alkaline and oxidative bleaching treatments had a positive impact on defibrillation and morphology of the fibers by the partial removal of non-cellulosic materials. FTIR results also revealed that most of the amorphous components were removed through proper alkali and bleaching treatments from the fibers. Further, SEM analysis showed that cellulose microfibers with an average diameter of 7 µm were successfully isolated with a yield of about 25%. The crystallinity index (76%) and crystallite size (3.41 nm) of CMF were also determined through the XRD analysis. The method used in this study led to the isolation of the microfibers with the thermal stability of 215°C and activation energy of 67.72 kJ/mol. The values obtained in this study were reasonably promising for the use of Yucca cellulose microfibers in various applications, such as reinforced-polymer manufacturing.

An efficient ultrasonic-assisted bleaching strategy customized for yak hair triggered by melanin-targeted Fenton reaction

Promoting processing efficiency and taking advantage of agricultural by-products are two promising ways to achieve sustainable textile industry. This study presents a customized efficient ultrasonic-assisted bleaching strategy for yak hair – a widely existing but underexploited secondary dark shade fibre from yak. A melanin-targeted Fenton oxidation process is established which involves three phases, i.e., (I) incorporation of Fe2+ ions with melanin, (II) catalytic oxidative bleaching using hydrogen peroxide (H2O2), and (III) reductive cleansing. The bleaching efficacy, dyeing performance and tensile property of yak hair treated with and without ultrasound were explored and compared. Further, the ultrasonic bleaching mechanism in terms of the catalytic effect of Fe2+ ions, the promotion of H2O2 decomposition, removal of melanin granule from yak hair, were demonstrated. Finally, the main effects and interactions of parameters in phase II, and optimal condition were obtained through mathematical modelling based on a central composite design (CCD). Results reveal that ultrasonic bleaching dramatically enhances the whiteness index (WI) of yak hair from 11 to 45 which is 44.6% higher than those bleached without ultrasound, and also promotes the uptake of acid dyes. There is only 15% tensile strength loss and 14% elongation increment of yak hair after ultrasonic bleaching, rising from a slight damage of cuticle layer and cleavage of disulfide bonds, respectively. In the study of bleaching mechanism, Fe2+ ion is confirmed to improve the H2O2 decomposition rate by 20.9% which further runs up to 35.9% after introducing ultrasound. Ultrasound increases the concentration of hydroxyl radicals (HO) by 94% which are the main oxidative species participating in bleaching confirmed by HO scavenging experiment. The porous structure was observed on the cross section of yak hair stemming from the removal of melanin granules contributed by the cleaning action of ultrasound. A theoretical highest WI of 52.4 can be achieved under an optimal condition based on the CCD study. In general, the proposed melanin-targeted bleaching strategy for yak hair that integrates ultrasonic technology and Fenton reaction, is beneficial to the development of sustainable textile industry from material and processing perspectives.

Effects of Cosmetic Emulsions on the Surface Properties of Mongolian Hair.

In the light of clean beauty and sustainability requirements emerging in the personal care market, the urgent need for the replacement of silicones in hair conditioners—with comparable performance and customer experience—has been highlighted in the industry. In this context, the goal of the present study was to investigate the physical effects of different silicone-free conditioner formulations on Mongolian hair after damage due to bleaching and compare the results to property changes induced by a classical silicone-containing formulation. To that end, the morphology, structure, and composition of strands and individual fibers of this hair type were characterized before and after bleaching by means of optical microscopy, atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS). It is shown that oxidative bleaching causes significant damage to the native hair surface, leading to local depletion or even large-area removal of the outer hydrophobic lipid layer. This results in enhanced wettability of the bleached hair by water (as confirmed by contact angle measurements) and is accompanied by an undesired loss of hair gloss and softness. Upon treatment with suitable cosmetic emulsions, the natural hydrophobicity of intact Mongolian hair can be partially or fully restored, with silicone-free formulations having effects similar to those of established silicone-containing products. The successive influence of bleaching and conditioning was further monitored using inverse gas chromatography (iGC), a technique that probes changes in surface energetics and polarity over an ensemble of an entire hair strand through interactions with specific molecules at the solid/gas interface. The resulting data mirror the macroscopic behavior of the bleached/conditioned hair and provide a quantitative scale for measuring damage and repair effects. Most notably, the effect of bleaching and subsequent conditioning on the haptic perception of hair strands could also be quantified with the aid of a biomimetic measurement system, which identifies increased friction (both tactile and sliding) as the major cause for the strawy feel of bleached hair and indicates successful relubrication after treatment with suitable conditioner formulations. Finally, the different physical properties determined for native, bleached, and reconditioned Mongolian hair are found to be reflected in application-oriented tests, namely in vitro measurements of wet and dry combing work. Overall, the data collected in this work shed novel light on the surface properties of Mongolian hair and highlight that effective hair conditioning after damage can be achieved without silicones in advanced cosmetic emulsions based on octyldodecyl myristate and glyceryl oleate.

Response of Properties and Chemicals to Preparation Parameters in the Oxidation Processing of Refined Montan Wax

Refined montan wax (RMW) is a lignite-based chemical product with wide application and high added value. However, research on its processing and performance is very limited. Currently, four parameters in the key preparation procedure for the oxidation bleaching of RMW, including the concentration of two oxidants (H2SO4 (P1) and CrO3 (P2)), oxidation time (P3), and the mass ratio of CrO3 used in two oxidation steps (P4), were systematically evaluated in regard to their impact on the properties and chemistry of RMW. The results showed that the four tested parameters visibly affected RMW, and each parameter had a different impact on the properties of RMW by range analysis, of which P1 showed a greater influence on its acid value; P2 influenced its friability, specific surface area, and aperture; P3 affected its color, initial melting point, and saponification value; and P4 had a higher impact on its final melting point, melting range, and hardness. Gas chromatography with flame ionization detection–mass spectrometry analysis revealed that the compounds found in RMW samples (RMWs) under different oxidation conditions differed significantly, with major differences in the content and amount of these components. Among the compounds in RMWs, 16 different compounds (variable importance of projection > 1) were found by the orthogonal projections to latent structures discriminant analysis method, nine of which have a strong relationship to the different performances of RMWs. This work provided a basis for the development of performance-oriented preparation processing technology for RMW.

Trichromatic Vat Dyeing of Cationized Cotton.

This article deals with cationization of cotton during mercerization and its effects on trichromatic vat dyeing. If cationization is carried out during the after-treatment, regardless of cotton pretreatment, the reaction takes place on the surface and blocks cellulose groups, subsequently resulting in uneven coloration. However, when cationization is carried out with an epihalohydrin during the mercerization process, new cellulose is formed in which the cationic compound is uniformly distributed and trapped between cellulose chains, resulting in uniform coloration after the dyeing process. The reaction time for the process during mercerization is 24 h, thus a more favorable process was researched. Based on electrokinetic analysis, it was found that 5 h was sufficient for the reaction with 3-chloro-2-hydroxypropyltrimethyl ammonium chloride (CHPTAC). The cationization of cotton contributed to the processes of vat dyeing. The change in charge upon cationization resulted in very high adsorption of vat-dye anions, indicating that ionic bonding occurred in addition to van der Waals forces. The color depth improved by more than 10 times. It should be emphasized that the colors with higher chroma and targeted color hue, especially in trichromatic dyeing, were obtained on cationized cotton, in contrast to standard cotton fabrics. The color differences obtained under the different light sources indicate the occurrence of metamerism. Considering the color fastness to laundering, vat-dyed cationized fabrics of all colors may be used in hospitals or other environments where high hygiene and oxidative bleaching are required.

Characterisation of microfibrils cellulose isolated from oil palm frond using high-intensity ultrasonication

This study highlighted the utilization of agricultural byproducts as an alternative fiber resource to be used as one of the materials for reinforcement biocomposite. Cellulose was extracted from oil palm frond using the alkaline treatment and successfully isolated into microfibril via the combination of carboxymethylation pre-treatment ultrasonication to get highly crystalline and good thermal stable microfibers. 4% NaOH was used during alkaline treatment and followed by oxidative bleaching with 30% H2O2. Once the extracted cellulose is chemically pre-treated with monochloroacetic acid, it was subjected to 30 minutes ultrasonication treatment to reduce its size. The detailed comparative analysis using SEM, FTIR and TGA was conducted in this work revealed some breakages of intramolecular hydrogen bonds and glycosidic bonds that occurred during the alkaline and bleaching treatment of oil palm biomass. The SEM images showed significant morphology of rigid, organized and highly ordered cellulose fibrils changed into aggregated fibril bundles of microfibrils after ultrasonication. The results from the infrared spectrums revealed that the mild alkaline treatments and oxidative bleaching were able to remove a large fraction of lignin and hemicelluloses to leave a clean cellulose sample. The isolated microfibrils cellulose exhibit good thermal stability as almost 50% of its initial mass remains at a temperature of 300 °C. These findings demonstrate that oil palm fronds can be utilized for biocomposite reinforcement applications.

HPLC–DAD profiling of a phenolic extract from Moroccan sweet Basil and its application as oxidative stabilizer of sunflower oil

Lipid oxidation is the major chemical phenomenon leading to the deterioration of edible oils by the diminution of their organoleptic and nutritional qualities. This study was aimed at profiling a phenolic extract from sweet Basil cultivated in Morocco and to investigate its possible protective effect against the oxidative process in sunflower edible oil as a natural alternative to synthetic antioxidants. The extract provides significant prevention of sunflower oil peroxidation after storage at 37 °C for 60 days. However, the effect was relatively less than that exerted by the BHA. Against, the phenolic extract significantly decreased the peroxidation value of oil after heating at 370 °C/5 h; the effect was comparable to that of BHA. Besides, the extract protects sunflower oil against oxidation induced by copper ion, but this activity remains statistically lower than that exerted by the BHA. Moreover, the DPPH radical scavenging activity of the phenolic extract is less than that recorded by the BHA. This extract inhibits also the oxidative bleaching of β-carotene relatively less than BHA. The extract contains 153.19 ± 1.05 mg/g total phenol. The HPLC analysis showed that the extract contains eight phenolic acids (caftaric acid, gallic acid, chlorogenic acid, caffeic acid, chicoric acid, rosmarinic acid, carnosic acid and p-hydroxybenzoic acid) and two flavonoids (rutin and luteolin-7 glucoside). In conclusion, we suggest that the phenolic Basil extract is a good source of natural antioxidants that might be exploited in edible oil preservation.

The effect of oxidative bleaching treatment on Yucca fiber for potential composite application

In the present study, natural cellulose fibers were extracted from the Yucca leaves, and the effect of oxidative treatment on the properties of fibers was studied. The effect of bleaching parameters on the morphology and physical properties of a cellulose fiber called the Yucca fiber was investigated using Taguchi’s experimental design (L27 orthogonal array). The whiteness index determined by reflectance spectroscopy increased by more than 38% because of the lignin removal. It was found that crystallinity, determined by X-ray diffraction (XRD) analysis, slightly increased by bleaching treatment due to the partial removal of non-cellulosic materials. Functional group analysis along with morphological analysis of the bleached fibers was conducted using Fourier transform infrared spectroscopy (FTIR) and Scanning electron microscopy (SEM) techniques, respectively. Thermal decomposition temperature obtained by thermogravimetric analysis (TGA) of the bleached fiber was found to increase about 40 °C. The results showed that the bleached fiber had good properties for use as a reinforcing material in polymer composites and the textile industry.

Figaro-tresses: A dataset for evaluating hair assembly features before and after cosmetic treatment.

The published database is composed of 1,080 images taken from 120 hair tresses made of medium blond, fine Caucasian hair with the aim to facilitate quantitative and qualitative studies about shampoo and conditioner efficacies. Two types of hair tresses were used: Caucasian hair which had not been subjected to oxidation with bleaching agents – virgin (60 tresses); and Caucasian hair, previously subjected to light oxidative bleaching – lightly bleached (remaining 60 tresses). Since cosmetic products such as shampoos and conditioners are often designed to subtly augment hair assembly features via the carefully balanced cumulative effects of deposited actives, each tress was subjected to consecutive washing+conditioning+drying cycles referred to as cosmetic treatment. The shampoo and conditioner used for this project were specifically selected for their suitability for fine hair. Each tress was photographed at three different time-points: before the cosmetic treatment; after two cosmetic treatments, and after an additional third cosmetic treatment. At each time-point, each tress was photographed from three different angles (−45, 0, and +45°), resulting in a total number of nine images for each tress. For each image in the database, we also provide a corresponding hair segmentation mask, which identifies the hair location area in the original image.

Light fading, rub and wash fastness of sulphur-dyed cotton fabrics aftertreated with cation–tannin protective system

PurposeSulphur dyes are the most highly consumed colourants for cellulosic substrates owing to their reasonable cost and acceptable fastness. However, the use of noxious conventional reducing agent, sodium sulphide and impaired wash fastness against oxidative bleaching is gradually decreasing the market of these dyes. As the need for “Green” goods and services is raising public awareness, this paper aims to use a glucose-based biodegradable reducing agent in place of sodium sulphide to dye cotton fabrics with a range of commercial sulphur dyes. The study also proposes an aftertreatment method to improve the fastness properties of the dyeing.Design/methodology/approachThe paper investigated the impact of a newly developed aftertreatment method on the fastness properties of dyeing. This involved the sequential application of a cationic fixing agent (Tinofix ECO) and tannin (Bayprotect CL) on the coloured fabrics and subsequent evaluation of colour strength, washing, light and rubbing fastness.FindingsThe effect of aftertreating the dyed cotton was found to significantly improve the light and wet rub fastness. The surface morphology of the dyeing remained unaffected as depicted by the absence of any finish residues.Research limitations/implicationsThe protective effect of the cation–tannin aftertreatments was examined with a view to providing the necessary commercial performance; however, it was established that the dry rub fastness was either reduced or remained unaffected and the wash fastness to International Organization for Standardization 105 C09 was also marginal.Originality/valueThis finishing technique is novel and can be found useful for manufacturing sulphur-dyed products with the improved light and wet rub fastness.

Design and Fine-Tuning Redox Potentials of Manganese(II) Complexes with Isoindoline-Based Ligands: H2O2 Oxidation and Oxidative Bleaching Performance in Aqueous Solution

A series of divalent manganese complexes [MII(HL1–6)Cl2] with the 1,3-bis(2’-Ar-imino)isoindolines (HLn, n = 1–6, Ar = pyridyl, 4-methylpyridyl, imidazolyl, thiazolyl, benzimidazolyl and N-methylbenzimidazolyl, respectively) including the previously reported ligands (HL1–2, 4–6) and complexes ([MII(HL1,5)Cl2]) have been prepared and characterized by electrochemical and spectroscopic methods. In these complexes, it was possible to control the redox potential of the metal center by varying the aryl substituent on the bis-iminoisoindoline moiety, and investigate its effect in a catalase-like reaction, and oxidative bleaching process in buffered aqueous solution. The kinetics of the dismutation of H2O2 into H2O and O2, and the oxidative degradation of morin by H2O2 were investigated in buffered water, where the reactivity of the catalysts in both systems was markedly influenced by the redox and Lewis acidic properties of the metal centers and the concentration of the bicarbonate ions. Both the catalase-like and bleaching activity of the catalysts showed a linear correlation with the MnIII/MnII redox potentials. The E1/2 spans a 561 mV range from 388 mV (Ar = benzymidazolyl) to 948 mV (Ar = 4-methylpyridyl) vs. the SCE. The amount of bicarbonate is a critical issue for the in situ formation of peroxycarbonate as a versatile oxidant, and its participation in the formation of high valent MnIV = O species.

Statistical Optimization of Biobleaching Efficacy of endo-β-1,4-xylanase from an Actinobacterium Streptomyces olivaceus (MSU3) in Comparison with Zinc Oxide Pretreated Sugarcane Bagasse Pulp Using Box–Behnken Design

ABSTRACT The bio-bleaching efficacy of endo-β-1,4-xylanase from an actinobacterium Streptomyces olivaceus (MSU3) was studied by using sugarcane bagasse pulp in comparison with chemical-mediated bleaching. Before that, the sugarcane bagasse pulp was processed with various concentrations of xylanase (20–100IU) and zinc oxide (0.2–1.0 g) individually through laboratory conditions. Simultaneously, both enzyme- and chemical-mediated bleaching process were optimized through response surface methodology by using the reaction condition containing pH 6.6, temperature 47°C with the incubation time of 3 h. The analysis of variance of the parameters expressed the maximum level of coefficient (R 2 = 0.963–0.996) with more significant (P < 0.0001). In bleaching process under-optimized conditions, the highest level of reducing sugar (110.02 mg/g), reduction of kappa number (14.69 k), degree of brightness (43.62%ISO), level of residual lignin (2.20%) with the discharge of phenolic (λ 237 = 0.119 OD), and hydrophobic (λ 465 = 0.046 OD) groups were attained in xylanase (80.0 IU) mediated bleaching than zinc oxide bleaching. Further, the effect of bleaching on processed pulp samples with loosening and changes of surface cell fiber was examined by field emission scanning electron microscopic analysis. The efficient fibrillation and porosity of pulp fiber were seen in xylanase bleached pulp than chemical-bleached pulp. These results clearly indicated that the endo-β-1,4-xylanase of the chosen actinobacterium could able to bleach the bagasse pulp effectively than the zinc oxide-mediated bleaching.

The Influence of Montan Resin in Crude Montan Wax on the Character and Performance of Refined Montan Wax

Montan resin removal and oxidation bleaching are two key procedures for preparing refined montan wax (RMW) from lignite and significantly affect the wax’s color appearance. However, due to the larg...

Cheating on forensic hair testing? Detection of potential biomarkers for cosmetically altered hair samples using untargeted hair metabolomics.

Hair analysis has become an integral part in forensic toxicological laboratories for e.g. assessment of drug or alcohol abstinence. However, hair samples can be manipulated by cosmetic treatments, altering drug concentrations which eventually leads to false negative hair test results. In particular oxidative bleaching of hair samples under alkaline conditions significantly affects incorporated drug concentrations. To date, current techniques to detect cosmetic hair adulterations bear limitations such as the implementation of cut-off values or the requirement of specialized instrumentations. As a new approach, untargeted hair metabolomics analysis was applied to detect altered, endogenous biomolecules that could be used as biomarkers for oxidative cosmetic hair treatments. For this, genuine hair samples were treated in vitro with 9% hydrogen peroxide (H2O2) for 30 minutes. Untreated and treated hair samples were analyzed using liquid-chromatography high-resolution time-of-flight mass spectrometry. In total, 69 metabolites could be identified as significantly altered after hair bleaching. The majority of metabolites decreased after bleaching, yet totally degraded metabolites were most promising as suitable biomarkers. The formation of biomarker ratios of metabolites decreasing and increasing in concentrations improved the discrimination of untreated and treated hair samples. With the results of this study, the high variety of identified biomarkers now offers the possibility to include single biomarkers or biomarker selections into routine screening methods for improved data interpretation of hair test results.

Preparation of a Highly Effective Organic Tanning Agent with Wide Molecular Weight Distribution from Bio‐Renewable Sodium Alginate

AbstractDialdehyde sodium alginate (DSA) with wide molecular weight distribution was prepared by periodate oxidation without alcohol‐precipitation. Its tanning properties in fur processing were investigated. It was found that this DSA could endow fur with high shrinkage temperature (Ts, 89 °C) and area yield (107%), showing better tanning properties than conventional dialdehyde sodium alginate product that was prepared by repeated alcohol‐precipitation process and thus had narrow molecular weight distribution. Low molecular weight components in DSA mainly contributed to crosslinkage and dispersion of the collagen fiber network, viz. tanning effect, while high molecular weight DSA components contributed to filling performance. SEM analysis illustrated that satisfactory dispersion of skin matrix and intact scale layer of wool were achieved by DSA tanning. The DSA tanned fur exhibited reasonable resistance to oxidation bleaching and presented a better performance in physical properties compared with traditional chrome tanned fur after fatliquoring. Besides, the DSA tanning system led to a better treatability of tanning and post‐tanning wastewaters in view of chrome‐free and higher biodegradability. The DSA with wide molecular weight distribution is a potential sustainable tanning agent in terms of both preparation and tanning processes.