Towards the Development of a Smart Detergent with Enhanced Safety and Efficiency for Pesticide Residue Removal from Fruits and Vegetables.

The research focused on the development and evaluation of special detergents for washing fruits and vegetables, with the primary emphasis on removing pesticide residues. The research aimed to improve food safety and meet consumer preferences for effective cleaning of food products. Using the cloud point characteristic of non-ionic surfactants, a 'smart' detergent was developed to adapt to typical washing conditions. Optimization of the detergent system composition was conducted and the properties of the surfactant system in relation to the cloud point were investigated to highlight the importance of precise control over detergent behavior in response to temperature changes. The physicochemical properties study of the model washing baths included surface tension, aggregate size, solubilization properties, and foaming ability. A model detergent, tailored for both cleaning efficacy and safety against the skin, was developed. Washing efficacy tests demonstrated the superior ability of the designed detergent to remove pesticide residues, eliminating consumer concerns and promoting healthier and safer food consumption. The conducted research paves the way for innovative and safe detergents for washing fruits and vegetables, thereby increasing food safety and consumer satisfaction.

Lipidomics Reveals the Effects of Detergents on Skin Surface Lipids in Young Adults.

BACKGROUND: Detergent is a chemical product commonly used in people's daily life. Contact with detergent solutions can damage the human skin barrier and cause skin diseases. Skin surface lipids (SSLs) play a decisive role in skin barrier function. This study aimed to observe the changes of SSLs in young adults after exposure to detergent solutions to explore the underlying mechanism of skin barrier function damage. METHODS: A self-controlled study on youth adults was conducted in Zhengzhou, China, in November 2020. The study lasted for a total of 1 week, and skin barrier function was assessed by trans-epidermal water loss (TEWL) values. The changes of SSLs before and after exposure to the detergent with subjects were measured using ultra-performance liquid chromatography quadrupole time of flight mass spectrometry. RESULTS: The skin barrier function of subjects' hands was impaired after exposure to detergent (TEWL value increased, p < 0.001). A total of 520 SSLs were detected, divided into 6 main categories. The average relative abundance of these 6 major lipids decreased after exposure. Sphingolipids (mainly ceramides), free fatty acids (mainly long-chain fatty acids), cholesterol lipids, and glycerophospholipids are the most severely damaged lipids. CONCLUSION: Detergent solutions can damage the skin barrier function and SSLs of young hands; interventions targeting SSLs to eliminate detergent damage to human skin may be of value.

Effect of alfalfa supplementary change dietary non-fibrous carbohydrate (NFC) to neutral detergent fiber (NDF) ratio on rumen fermentation and microbial function in Gansu alpine fine wool sheep (Ovis aries).

Bodyweight loss and rumen microbial dysfunction of grazing sheep was a challenge for the sheep production industry during cold season, which were considered to correlated with under-roughage-feeding. Alfalfa is a good roughage supplementary for ruminants, which can improve grazing sheep bodyweight-loss and rumen microbial dysfunction during grass-withering period. This study evaluated the effects of alfalfa hay supplementary change dietary non-fibrous carbohydrate/neutral detergent fiber (NFC/NDF) ratios on rumen fermentation and microbial function of Gansu alpine fine wool sheep during extreme cold season. 120 ewes (3-4 yrs) with an average body weight of 28.71 ± 1.22 kg were allocated randomly into three treatments, and fed NFC/NDF of 1.92 (H group), 1.11 (M group), and 0.68 (L group), respectively. This study was conducted for 107 d, including 7 d of adaption to the diets. The rumen fermentation parameters and microbial characteristics were measured after the end of feeding trials. The results showed that the concentrations of sheep body weight, nitrogen components (Total-N, Soluble protein-N and Ammonia-N), blood biochemical indices (LDH, BUN and CHO) and ruminal volatile fatty acids (TVFA and propionate) significantly increased with an increase in the proportion of NFC/NDF ratios (p < .05), and the acetate and acetate/propionat ratio presented a contrary decreasing trend (p < .05). A total of 1018 OTUs were obtained with 97% consistency. Ruminococcus, Ruminococcaceae and Prevotella were observed as the predominant phyla in ruminal fluid microbiota. Higher NFC/NDF ratios with Alfalfa supplementary increased the richness and diversity of ruminal fluid microbiota, and decreased ruminal fluid microbiota beta-diversity. Using clusters of orthologous groups (COG), the ruminal fluid microbiota of alfalfa supplementary feeding showed low immune pathway and high carbohydrate metabolism pathway. In summary, the study suggested that there was an increasing tendency in dietary NFC/NDF ratio of 1.92 in body weight, ruminal fermentation, microbial community composition and fermentation characteristics through developing alfalfa supplementary system.

Efficacy of point source legislation quantified for a 64-year river water quality trajectory of phosphorus loading.

Changes in river water quality often follow typical trajectories characterized by sequential phases of degradation and recovery induced by management measures, typically achieved with combinations of legislative and technological interventions. However, the key question about the effectiveness of the different types of legal interventions - source control, use-related, and end-of-pipe - remains poorly understood. With the case of phosphorus (P), which is a valuable indicator of surface water quality and a widespread target of legislation at various governance levels in order to control eutrophication of water bodies, we quantified the relation between point source loading of P and resulting river water quality for a multidecadal trajectory of the river Ruhr (Germany). In particular, we analysed P-related legislation targeting point source pollution enforced at EU, national, state, and local level and linked their development with measured total phosphorus (TP) concentrations in the river Ruhr (Germany). To this end, we combined archival data with information in the literature and conducted interviews with contemporary witnesses to describe and quantify the efficacy of each legislative approach. Although not specifically targeted at P reduction, end-of-pipe measures (sewer systems and wastewater treatment plants (WWTP)) reduced TP inputs to surface waters already in the 1960s and 1970s, curbing TP inputs to the Ruhr by 38% in 1980. The first targeted source control legislation - the banning of phosphates in textile detergents in 1981 - effectively reduced TP concentrations in WWTP influents by 36% since 1990. In combination with stronger end-of-pipe legislation focusing on P elimination in WWTP since the 1990s, TP concentrations in WWTP effluents were reduced by 86% at the end of the 1990s and by 92% in 2021. Complete and successful source control for textile detergents made use-related legislation redundant. Our study demonstrates that source control measures should be prioritized, because they are the fastest way to curb emissions. These findings provide insights that can inform efficient decision-making regarding water quality in a trajectory perspective of hierarchical governance and technological needs, as well as effective policy-making and management for other pollutants requiring control from point sources.

Ionic Detergent Under Pressure-Vacuum as an Innovative Strategy to Generate Canine Tracheal Scaffold for Organ Engineering.

Decellularized scaffolds applied in tissue engineering offer improvements, supplying the elevated necessity for organs and tissues for replacement. However, obtaining a functional trachea for autotransplantation or allotransplantation is tricky due to the organ anatomical and structural complexity. Most tracheal decellularization protocols are lengthy, expensive, and could damage the tracheal extracellular matrix (ECM) architecture and functionality. Here, we aimed to evaluate the effectiveness of 3 different decellularization protocols combined with chemical and physical methods to obtain acellular canine tracheal scaffolds. Six adult dog tracheas were incised (tracheal segments) resulting in 28 rings for control tissue and 84 rings for decellularization (5-7 mm thick). Subsequently, decellularized tracheal scaffolds were microscopically/macroscopically characterized by histological analysis (Hematoxylin-Eosin, Masson's trichrome, Picrosirius red, Alcian blue, and Safranin O), immunohistochemistry for ECM components, scanning electron microscopy, and genomic DNA quantification. After decellularization, the tracheal tissue revealed reduced genomic DNA, and maintenance of ECM components preserved (structural proteins, adhesive glycoproteins, glycosaminoglycans and proteoglycans), suggesting ECM integrity and functionality. Comparatively, the combined ionic detergent with high vacuum pressure decellularization protocol revealed superior genomic DNA decrease (13.5 ng/mg) and improvement on glycosaminoglycans and proteoglycans preservation regarding the other decellularized trachea scaffolds and native tissue. Our results indicate that the 3 chemical/physical protocols reduce the decellularization time without ECM proteins damage. Notwithstanding, the use of ionic detergent under vacuum pressure was able to generate an innovative strategy to obtain acellular canine tracheal scaffolds with the highest levels of adhesive proteins that support its potentiality for recellularization and future tissue engineering application.

Optimized production of keratinolytic proteases from Bacillus tropicus LS27 and its application as a sustainable alternative for dehairing, destaining and metal recovery.

The present study describes the isolation and characterization of Bacillus tropicus LS27 capable of keratinolytic protease production from Russell Market, Shivajinagar, Bangalore, Karnataka, with its diverse application. The ability of this strain to hydrolyze chicken feathers and skim milk was used to assess its keratinolytic and proteolytic properties. The strain identification was done using biochemical and molecular characterization using the 16S rRNA sequencing method. Further a sequential and systematic optimization of the factors affecting the keratinase production was done by initially sorting out the most influential factors (NaCl concentration, pH, inoculum level and incubation period in this study) through one factor at a time approach followed by central composite design based response surface methodology to enhance the keratinase production. Under optimized levels of NaCl (0.55 g/L), pH (7.35), inoculum level (5%) and incubation period (84 h), the keratinase production was enhanced from 41.62 U/mL to 401.67 ± 9.23 U/mL (9.65 fold increase) that corresponds to a feather degradation of 32.67 ± 1.36% was achieved. With regard to the cost effectiveness of application studies, the crude enzyme extracted from the optimized medium was tested for its potential dehairing, destaining and metal recovery properties. Complete dehairing was achieved within 48 h of treatment with crude enzyme without any visible damage to the collagen layer of goat skin. In destaining studies, combination of crude enzyme and detergent solution [1 mL detergent solution (5 mg/mL) and 1 mL crude enzyme] was found to be most effective in removing blood stains from cotton cloth. Silver recovery from used X-ray films was achieved within 6 min of treatment with crude enzyme maintained at 40 °C.

Cyclic pressure induced decellularization of porcine descending aortas.

The demand for decellularized xenogeneic tissues used in reconstructive heart surgery has increased over the last decades. Complete decellularization of longer and tubular aortic sections suitable for clinical application has not been achieved so far. The present study aims at analyzing the effect of pressure application on decellularization efficacy of porcine aortas using a device specifically designed for this purpose. Fresh porcine descending aortas of 8 cm length were decellularized using detergents. To increase decellularization efficacy, detergent treatment was combined with pressure application and different treatment schemes. Quantification of penetration depth as well as histological staining, scanning electron microscopy, and tensile strength tests were used to evaluate tissue structure. In general, application of pressure to aortic tissue does neither increase the decellularization success nor the penetration depth of detergents. However, it is of importance from which side of the aorta the pressure is applied. Application of intermittent pressure from the adventitial side does significantly increase the decellularization degree at the intimal side (compared to the reference group), but had no influence on the penetration depth of SDC/SDS at both sides. Although the present setup does not significantly improve the decellularization success of aortas, it is interesting that the application of pressure from the adventitial side leads to improved decellularization of the intimal side. As no adverse effects on tissue structure nor on mechanical properties were observed, optimization of the present protocol may potentially lead to complete decellularization of larger aortic segments.

Can conventional forages be replaced with cotton plant (Gossypium hirsutum) wastes in fattening lambs? Laboratory and animal studies.

The cotton plant (Gossypium hirsutum) is a shrub native to many arid and semi-arid regions around the world, while the nutritional value of its wastes has been less scientifically investigated. Different components of whole cotton plant wastes (WCPW) including leaf blade, cotton pod, stem, root, bract, petiole, and cottonseed were evaluated for their nutritional values by standard laboratory methods. After that, we tested the WCPW for partial substitution (0, 20, 40, and 60% substitution or 0, 10, 20, and 30% of dietary dry matter (DM)) with dietary common forage in a completely randomized design with 32 feedlot male lambs for 90 days. A diverse range of chemical and mineral compositions was found among the different WCPW's components. The cottonseed had the highest crude protein (CP) and ether extract (EE) contents, while the lowest neutral detergent fiber (NDF) and acid detergent fiber (ADF) were observed in the leaf blade (P < 0.0001). The highest contents of calcium, phosphorus, sodium, magnesium, and iron were also observed in the leaf blade (P < 0.0001). Higher potential gas production, in vitro organic matter digestibility (OMD), in vitro dry matter digestibility (DMD), and total volatile fatty acids (TVFA) were also related to the leaf blade (P < 0.0001). Bract had the highest acid-base buffering capacity (P < 0.0001). The lambs fed on 30% of dietary DM with WCPW exhibited lower final body weight (BW), average daily gain (ADG), CP or NDF digestibility, ruminal TVFA, propionate, plasma total protein, and higher feed conversion ratio (FCR) compared to the control group. Generally, WCPW can be substituted up to 40% of common forages (or 20% of diet DM) without any adverse effect on growth performance and blood metabolites of feedlot lambs, especially during feed shortages.

Association of the chemical composition and nutritional value of forage resources in Colombia with methane emissions by enteric fermentation.

In the livestock sector, strategies are available to mitigate gas emissions, such as methane, one of the alternatives that have shown potential correspondence to changes in the composition of the diet. The main aim of this study was to analyze the influence of methane emissions with data on enteric fermentation obtained from the Electronic Data Gathering, Analysis, and Retrieval (EDGAR) database and based on forecasts of methane emissions by enteric fermentation with an autoregressive integrated moving average (ARIMA) model and the application of statistical tests to identify the association between methane emissions from enteric fermentation and the variables of the chemical composition and nutritional value of forage resources in Colombia. The results reported positive correlations between methane emissions and the variables ash content, ethereal extract, neutral detergent fiber (NDF), and acid detergent fiber (ADF) and negative correlations between methane emissions and the variables percentage of unstructured carbohydrates, total digestible nutrients (TDN), digestibility of dry matter, metabolizable energy (MERuminants), net maintenance energy (NEm), net energy gain (NEg), and net lactation energy (NEI). The variables with the most significant influence on the reduction of methane emissions by enteric fermentation are the percentage of unstructured carbohydrates and the percentage of starch. In conclusion, the analysis of variance and the correlations between the chemical composition and the nutritive value of forage resources in Colombia help to understand the influence of diet variables on methane emissions of a particular family and with it in the application of strategies of mitigation.

Effect of coagulation on microfibers in laundry wastewater.

Microplastics pollution in the aquatic system has received significant attention due to their recalcitrant nature and ecotoxicological threat. Municipal wastewater typically contains various microplastics with synthetic microfibers as a significant constituent from the laundry process. The fate of microfibers in conventional wastewater processes is not clearly understood. In this study, the effect of coagulation on microfibers obtained from a lint screen of a domestic dryer and resuspended in pure water, and also in laundry wastewater was investigated using ferric chloride and polyaluminum chloride (PACl). The removal efficiency of the microfibers resuspended in pure water varied from 86% to 96% depending on the fiber size ranges: < 90 µm, 90-125 µm, and >125 µm with the smaller size microfibers showing a lower removal efficiency. Surfactant present in detergent in laundry wastewater reduced the microfibers removal efficiency to 0-37%, however, the addition of PACl increased microfibers removal to 90%. The optimal PACl concentrations for ≥90% removal were 1.75, 2, 4, and 6 mg/L for 0.5, 2, 4, 8 mg/L detergent, respectively. Zeta potential, FTIR, and SEM analysis were applied to observe the surface changes of microfibers during coagulation indicating possible mechanisms of coagulation. The dominant mechanisms for coagulation of microfibers by FeCl3 and PACl seem to be charge neutralization and adsorption-bridging. This work provided some insights about the fate of laundry microfibers in primary treatment processes.

PDE concept for controlling cleaning agent residues in pharmaceuticals- A critical analysis.

Cleaning agents (CAs) are used in multipurpose facilities to control carryover contamination of active pharmaceutical ingredients (APIs) to scientifically justified limits. While this is often done with the PDE methodology used for API impurities, it is unclear if it is justifiable and necessary for cleaning agents, which generally represent a comparatively lower health risk. Comparing calculated oral PDE values for CA ingredients (CAIs) from four companies with PDEs of a selected number of small-molecule APIs showed that the toxicity of CAIs is several orders of magnitude lower. Furthermore, a critical review of the toxicity and everyday exposure to the general population of the main CAIs functional groups showed that the expected health risks are generally negligible. This is particularly true if the associated mode of actions cause local toxicity that is usually irrelevant at the concentration of potential residue carryover. This work points towards alternative approaches to the PDE concept to control CAIs' contamination and provides some guidance on grouping and identifying compounds with lower health risks based on exposure and mode of action reasoning. In addition, this work supports the concept that limit values should only be set for CAIs of toxicological concern.

Aponeurosis discission, a low-detergent method for tissue-engineered acellular ligament scaffolds.

Detergent treatment is the most commonly used method for the decellularization of ligaments and tendon grafts. However, it is well recognized that detergent treatment can also adversely affect the extracellular matrix. This study found that discission into the aponeurosis layer of the patellar tendon (PT) before decellularization is conducive to extracting cells from the PT using a low quantity of detergent in a short time period. The acellular aponeurosis discission ligament (AADL) retains its native collagen fibril structure and mechanical properties. Moreover, the PT retained cell and tissue compatibility in vitro and in vivo. After implantation into a defective allogeneic PT, we found that the AADL healed well in the host, and its collagen structure exhibited gradual improvement 12 months after implantation with satisfactory reconstruction. IMPACT: The aponeurosis of tendons/ligaments is the main barrier to achieving complete decellularization, and it thus prevents complete recellularization for applications in tissue engineering. Aponeurosis can obstruct the removal of cell components. We found that excising the aponeurosis before decellularization allows for the removal of cellular components with a reduced amount of detergent, thus improving the biological properties of the acellular ligament. To the best of our knowledge, no similar studies have been performed. Graphical abstract.

Comparative study of decellularization techniques to obtain natural extracellular matrix scaffolds of human peripheral-nerve allografts.

BACKGROUND: We hypothesize that adding sonication cycles to the process of decellularization of cadaveric human peripheral nerves will increase the removal of cell debris and myelin sheath, increasing their utility as allografts. METHODS: Our aim of this study was to develop a decellularization protocol that allows the removal of cells and myelin sheath without detrimental effects on nerve architecture. Segments of ulnar and median nerves from human donors, isolated both before and after cardiac arrest, were subjected to two methods of decellularization: two-detergent-based (M1) and the same method with sonication added (M2). We evaluated the histology of unprocessed and decellularized nerves (n = 24 per group) for general morphology, presence of cell nuclei, nuclear remnants, collagen fibers, and myelin. We performed immunohistochemistry to verify the removal of Schwann cells associated with histomorphometry. We used scanning electron microscopy (EM) to evaluate the ultrastructure of both native and decellularized nerves. The efficacy of decellularization was assessed by analysis of genomic DNA. RESULTS: Histology confirmed that both decellularization protocols were adequate and maintained natural nerve architecture. Scanning EM showed that 3D ultrastructural architecture also was maintained. Histomorphometric parameters showed a more complete removal of the myelin with the M2 protocol than with M1 (p = 0.009). Fiber diameter and density were not modified by decellularization methods. CONCLUSIONS: Sonication can be a complementary method to decellularization of peripheral nerve allografts with sonication increasing the effectiveness of detergent-based protocols for the removal of unwanted cellular components from peripheral nerve allografts.

Distribution of Burkholderia cepacia complex species isolated from industrial processes and contaminated products in Argentina.

Burkholderia cepacia complex (Bcc) members have clinical relevance as opportunistic pathogens in patients with cystic fibrosis and are responsible of numerous nosocomial infections. These closely related bacteria are also reported as frequent contaminants of industrial products. In this retrospective study, we use PCR and recA gene sequence analysis to identify at species level Bcc isolates recovered from massive consumption products and industrial processes in Argentina during the last 25 years. The sequences obtained were also compared with recA sequences from clinical Bcc isolates deposited in GenBank database. We detected Bcc in purified water and preserved products from pharmaceutics, cosmetics, household cleaning articles, and beverages industries. B. contaminans (which is prevalent among people with cystic fibrosis in Argentina) was the most frequent Bcc species identified (42% of the Bcc isolates studied). B. cepacia (10%), B. cenocepacia (5%), B. vietnamiensis (16%), B. arboris (3%), and the recently defined B. aenigmatica (24%) were also detected. Rec A sequences from all B. cepacia and most B. contaminans industrial isolates obtained in this study displayed 100% identity with recA sequences from isolates infecting Argentinean patients. This information brings evidence for considering industrial massive consumption products as a potential source of Bcc infections. In addition, identification at species level in industrial microbiological laboratories is necessary for a better epidemiological surveillance. Particularly in Argentina, more studies are required in order to reveal the role of these products in the acquisition of B. contaminans infections.

Fast and Robust Quantification of Detergent Micellization Thermodynamics from Isothermal Titration Calorimetry.

Detergents are widely used in modern in vitro biochemistry and biophysics, in particular to aid the characterization of integral membrane proteins. An important characteristic of these chemicals in aqueous solutions is the concentration above which their molecular monomers self-associate to form micelles, termed the critical micellar concentration (CMC). Micelles are supramolecular assemblies arranged with the hydrophobic portions oriented inward and the hydrophilic head groups positioned outward to interact with the aqueous solvent. Knowledge of the CMC is not only of practical relevance but also of theoretical interest because it provides thermodynamic insights. Isothermal titration calorimetry (ITC) is a powerful method to determine CMCs, as it furnishes additional information on the enthalpy and entropy of micellization. Here we describe our extension of previous methods to determine CMCs and other thermodynamic parameters from ITC demicellization curves. The new algorithm, incorporated into the stand-alone software package D/STAIN, analyzes ITC demicellization curves by taking advantage of state-of-the-art thermogram-integration techniques and automatically providing rigorous confidence intervals on the refined parameters. As a demonstration of the software's capabilities, we undertook ITC experiments to determine the respective CMCs of n-octyl ß-d-glucopyranoside (OG), n-dodecyl ß-d-maltopyranoside (DDM), and lauryldimethylamine N-oxide (LDAO). Motivated by the fact that in vitro membrane protein studies often require additives such as precipitants (e.g., polyethylene glycol (PEG)), we also carried out ITC demicellization studies in the presence of PEG3350, finding in all cases that PEG had significant effects on the thermodynamics of detergent micellization.

Determination of antibiotics and detergent residues in decellularized tissue-engineered heart valves using LC-MS/MS.

Residual chemicals that are presented during tissue processing in human tissue banks can be a risk for the allograft recipient. Determine the residual concentrations of the antibiotics and detergent used in the process of human decellularized tissue-engineered heart valves stored in isotonic saline solution up to 18 months. A total of 24 human decellularized allografts were stored in sterile sodium chloride and analyzed immediately after the decellularization process (0 months) and after storage for 6, 12, and 18 months, which includes the use of sodium dodecyl sulfate (SDS) and antibiotics (cefoxitin, vancomycin hydrochloride, lincomycin hydrochloride, polymyxin B sulfate). These valves were used for suitability tests, the zone of inhibition evaluation, and direct contact cytotoxicity assay. The stock solution from 32 valves was used for LC-MS/MS analysis of antibiotics and SDS. Tissue samples from decellularized valves showed a zone of inhibition formation for S. aureus and B. subtilis, suggesting the presence of an inhibitory molecule in the tissue. Cytotoxicity tests were negative. Polymyxin B, vancomycin, and SDS were detected and quantified in human decellularized aortic and pulmonary allografts during all periods of the study. There were no traces of residual cefoxitin and lincomycin in the tissue stock solution. We found residual concentrations of the antibiotics and detergent used in the process of human decellularized tissue-engineered heart valves stored in isotonic saline solution up to 18 months.

Development of a ssDNA aptamer system with reduced graphene oxide (rGO) to detect nonylphenol ethoxylate in domestic detergent.

Endocrine-disrupting chemicals are a major public health problem throughout the world. In the human body, these compounds functionalize the same as sexual hormones, inducing precocious puberty, gynecomastia, etc. To help prevent this occurrence, a simple detection system is needed. In this study, a nonylphenol ethoxylate (NPE)-specific aptamer was selected by reduced graphene oxide-systematic evolution of ligands by exponential enrichment. A random ssDNA library was incubated with rGO for adsorption, followed by elution with the target molecule. As a result of screening, a DNA aptamer was found that specifically bounds to the target with high binding affinity (Kd  = 100.9 ± 13.2 nM) and had a low limit of detection (LOD = 696 pM). Furthermore, this NPE-binding aptamer bounds selectively to the target. Characterization of the aptamer was confirmed by measuring the fluorescence signal recovery from rGO. In addition, detection of NPE was performed with several water samples, and the detection accuracy was 100 ± 10%. From these results, we expect that this aptamer could be applied to an on-site detection system for NPE in industrial sites or domestic fields.

Characterization of airborne particles from cleaning sprays and their corresponding respiratory deposition fractions.

Cleaning workers are exposed to many risk factors, including handling of cleaning products. Epidemiological studies show that they have a high incidence of asthma and other respiratory symptoms. Some studies have indicated an even higher incidence of asthma in individuals using cleaning sprays regularly. It is known that sprays produce an aerosol that can expose the respiratory system to chemicals. Knowledge of the physical characteristics of the airborne particles, as well as the characteristics of the gas phase, is needed to determine how they affect the respiratory tract and why they cause airway symptoms. The aim of this study was to characterize the aerosols from seven different ready-to-use trigger cleaning sprays in terms of total airborne mass fraction, particle size distribution, and new particle formation from ozone reactions. An additional aim was to calculate the respiratory deposition fraction of the measured particles. The total airborne mass fraction was determined by comparing the mass deposited on the chamber wall with the mass emitted from the bottle during spraying. Particle number concentration and size distribution of the airborne particles were measured using an aerodynamic particle sizer and a fast aerosol mobility size spectrometer. The total airborne mass fraction was between 2.7% and 32.2% of the mass emitted from the bottle, depending on the product. Between 0.0001% and 0.01% of the total airborne mass fraction consisted of residual particles. However, these particles had a mass median aerodynamic diameter between 1.9 µm and 3.7 µm, constituting a total respiratory deposition of up to 77%. New particle formation in the presence of ozone was also shown to vary between 5,000 cm-3 and 35,000 cm-3 depending on the product, in the studied settings. These findings confirm that a substantial part (up to 1/3) of the mass sprayed from the bottle does not reach the intended surface. Thus, the use of cleaning sprays can result in chemical airway exposure, with particles in the relevant size range for both nasal and alveolar deposition.

[Determination of anionic synthetic detergent in drinking water by methylene blue spectrophotometry].

OBJECTIVE: To develope a method for rapid determination of anionic synthetic detergent in drinking water by methylene blue spectrophotometry. METHODS: Added 20. 0 mL water sample into 50 mL plastic tube, then added 10. 0 mL chloroform and 200 µL methylene blue solution, oscillatied 1 min, layering, suck out the upper solution, calibrated zero using chloroform, determinated the absorbance of the bottom extraction solution at 650 nm wavelength. RESULTS: The regression equations of the rapid determination method showed a good linearity and the correlation coefficient was 0. 9995. The method minimum mass detection concentration was 0. 05 mg/L. The recoveries were between 92. 7% and 98. 3%, and the relative standard deviations were between 4. 8% and 5. 7%(n=6). Compared with the national standard method by significance test, the significant difference had no statistical significance(P=0. 79). The detection time(30 samples) was only 2 h which needed a day by using national standard method. The concentration range of anionic synthetic detergent of 30 samples in the Yanqing urban areas of Beijing were<0. 05-0. 26 mg/L. CONCLUSION: This method is simple, sensitive, accurate and efficient, and it is suitable for basic level laboratories rapid determination and drinking water surveillance.

Identification of Poly(ethylene glycol) and Poly(ethylene glycol)-Based Detergents Using Peptide Search Engines.

Poly(ethylene glycol) (PEG) is one of the most common polymer contaminations in mass spectrometry (MS) samples. At present, the detection of PEG and other polymers relies largely on manual inspection of raw data, which is laborious and frequently difficult due to sample complexity and retention characteristics of polymer species in reversed-phase chromatography. We developed a new strategy for the automated identification of PEG molecules from tandem mass spectrometry (MS/MS) data using protein identification algorithms in combination with a database containing "PEG-proteins". Through definition of variable modifications, we extend the approach for the identification of commonly used PEG-based detergents. We exemplify the identification of different types of polymers by static nanoelectrospray tandem mass spectrometry (nanoESI-MS/MS) analysis of pure detergent solutions and data analysis using Mascot. Analysis of liquid chromatography-tandem mass spectrometry (LC-MS/MS) runs of a PEG-contaminated sample by Mascot identified 806 PEG spectra originating from four PEG species using a defined set of modifications covering PEG and common PEG-based detergents. Further characterization of the sample for unidentified PEG species using error-tolerant and mass-tolerant searches resulted in identification of 3409 and 3187 PEG-related MS/MS spectra, respectively. We further demonstrate the applicability of the strategy for Protein Pilot and MaxQuant.