Modified Natural Rubber as a Simple Chemical Sensor with Smartphone Detection for Formaldehyde Content in a Seafood Sample

A new biodegradable platform-based sensor for formaldehyde assay is proposed. Natural rubber latex was modified to polylactic acid–chloroacetated natural rubber polymer blend sheets. The polymer blend sheet was grafted using a water-based system with amine monomers as a platform, with a spot exhibiting positive polarity for immobilizing with anionic dye (Acid Red 27). The sensor was exposed to formaldehyde. The color intensity of the dye on the sensor spot would decrease. Using a smartphone with image processing (via ImageJ program), the color intensity change (∆B) could be followed. A linear calibration, ∆B intensity = 0.365 [FA] + 6.988, R² = 0.997, was obtained for 10–150 mM FA with LOD and LOQ at 3 and 10 mM, respectively (linear regression method). The precision was lower than 20% RSD. Application to real seafood samples was demonstrated. The ready-to-use sensor with the proposed method was cost-effective, was portable for on-site analysis, and demonstrated green chemical analysis.     

Effects of arsenobetaine,a major organic arsenic compound in seafood,on the maturation and functions of human peripheral blood monocytes,macrophages and dendritic cells

We examine the in vitro immunotoxicity of synthetically pure arsenobetaine [AsBe; trimethyl (carboxymethyl) arsonium zwitterion], which is a major organic arsenic compound in seafood, on various human immune cells, such as peripheral blood monocytes, monocyte‐derived macrophages and monocyte‐derived dendritic cells (DCs). In particular, we examine the differentiation of monocytes into macrophages or DCs by comparing the effects of AsBe with those pentavalent inorganic arsenate. AsBe neither enhanced nor inhibited the differentiation of human monocytes into macrophages or DCs, and also did not affect their various immune functions. Furthermore, AsBe had no cytolethality in monocyte‐derived macrophages or DCs even at a concentration of 5 mmol l⁻¹. In contrast, inorganic arsenate showed strong cytolethality in these human immune cells in vitro at micromolar concentrations. These data indicate that the organic arsenic compound AsBe in seafood has no in vitro immunotoxicity in human immune cells. Copyright © 2004 John Wiley & Sons, Ltd.     

Plant-Based Seafood Analogs

There is a growing global need to shift from animal- towards plant-based diets. The main motivations are environmental/sustainability-, human health- and animal welfare concerns. The aim is to replace traditional animal-based food with various alternatives, predominantly plant-based analogs. The elevated consumption of fish and seafood, leads to negative impacts on the ecosystem, due to dwindling biodiversity, environmental damage and fish diseases related to large-scale marine farming, and increased intake of toxic substances, particularly heavy metals, which accumulate in fish due to water pollution. While these facts lead to increased awareness and rising dietary shifts towards vegetarian and vegan lifestyles, still the majority of seafood consumers seek traditional products. This encourages the development of plant-based analogs for fish and seafood, mimicking the texture and sensorial properties of fish-meat, seafood, or processed fish products. Mimicking the internal structure and texture of fish or seafood requires simulating their nanometric fibrous-gel structure. Common techniques of structuring plant-based proteins into such textures include hydrospinning, electrospinning, extrusion, and 3D printing. The conditions required in each technique, the physicochemical and functional properties of the proteins, along with the use of other non-protein functional ingredients are reviewed. Trends and possible future developments are discussed.     

Levels of mercury,cadmium, lead and other selected elements in canned tuna fish commercialised in Jordan

During 2010, the concentrations of mercury and eight other trace elements in 90 canned tuna samples commercialised in Jordan were determined using mercury analyser (Hydra C®) and the inductively coupled plasma-optical emission spectrometer (ICP-OES). The mean concentrations and ranges for elements analysed in mg?kg ^{? 1} (wet base) were as follows: total Hg (0.21; 0.06–0.57), Cd (0.06;?<?0.01–0.63), Pb (0.09; <0.04–0.24), total As (0.74; 0.11–1.56), Ni (0.51; 0.03–2.85), V (0.04; <0.03–0.1), Al (0.26; 0.08–1.63), Ba (0.13; 0.05–0.42) and Ag was not detected in any of the analysed samples (<0.02?mg?kg^?1). The data obtained in the present study compared well with data obtained from similar studies carried out in different parts of the world. Few samples had the mercury and cadmium levels slightly exceeding the Codex Committee on Food Additives and Contaminants draft guidelines. However, the estimated weekly intakes of these metals showed that there was no health risk associated with the consumption of the analysed canned tuna samples.     

Sample treatment selection for routine mercury speciation in seafood by gas chromatography–atomic fluorescence spectroscopy

A general analytical strategy for mercury speciation in seafood samples has been proposed to increase sample throughput. This consists of the initial determination of total mercury content, and then mercury speciation using gas chromatography coupled to atomic fluorescence spectroscopy. The appropriate sample treatment for mercury speciation is selected between a method based on aqueous ethylation with sodium tetraethylborate (Approach A: a rapid methodology for samples with methylmercury concentrations between 150 and 2000 ng g^?1) and another one based on the determination of organomercury chlorides (Approach B: a much more time‐consuming methodology, applicable to samples with methylmercury at 1.2–200 ng g^?1). Both procedures have been used together for the analysis of bivalves and fish samples. Copyright © 2005 John Wiley & Sons, Ltd.     

聚苯硫醚副产物浆料的分离及氯化锂的回收研究

聚苯硫醚(PPS)的工业合成采用对二氯苯和硫化钠为原料,N-甲基-2-吡咯烷酮(NMP)为溶剂,氯化锂为助剂,经加压缩聚反应而成.该反应除了获得PPS外,还产生一部分副产物淤浆,有必要对其组成物进行分离回收和资源化利用.本文采用四氢呋喃(THF)为添加剂对这种副产物淤浆进行了分离研究,并对其中的锂盐进行了回收研究.结果表明,采用THF添加剂可以较为容易地将浆料分离为PPS低聚物、NMP以及无机盐,采用有机溶剂提取法可以回收氯化锂,LiCl的回收率可达40%.     

Rapid IC-ICP/MS method for simultaneous analysis of iodoacetic acids, bromoacetic acids, bromate, and other related halogenated compounds in water

Haloacetic acids (HAAs) and bromate are toxic water disinfection by-products (DBPs) that the U.S. Environmental Protection Agency has regulated in drinking water. Iodoacetic acids (IAAs) are the emerging DBPs that have been recently found in disinfected drinking waters with higher toxicity than their corresponding chloro- and bromo-acetic acids. This study has developed a new rapid and sensitive method for simultaneous analysis of six brominated and four iodinated acetic acids, bromate, iodate, bromide, and iodide using ion chromatography-inductively coupled plasma-mass spectrometry (IC-ICP-MS). Mono-, di- and tri-chloroacetic acids are not detected by this method because the sensitivity of ICP-MS analysis for chlorine is poor. Following IC separation, an Elan DRC-e ICP-MS was used for detection, with quantitation utilizing m/z of 79, 127, and 74 amu for Br, I, and Ge (optional internal standard) species, respectively. Although the primary method used was an external standard procedure, an internal standard method approach is discussed herein as well. Calibration and validation were done in a variety of natural and disinfection-treated water samples. The method detection limits (MDLs) in natural water ranged from 0.33 to 0.72 μg L⁻¹ for iodine species, and from 1.36 to 3.28 μg L⁻¹ for bromine species. Spiked recoveries were between 67% and 123%, while relative standard deviations ranged from 0.2% to 12.8% for replicate samples. This method was applied to detect the bromine and iodine species in drinking water, groundwater, surface water, and swimming pool water.     

Changes in the Volatile Profile of Wheat Sourdough Produced with the Addition of Cava Lees

The volatile fraction is of great importance for the organoleptic quality and consumer acceptance of bread. The use of sourdough improves the sensory profile of bread, as well as the addition of new ingredients to the fermentation. Cava lees are a sparkling wine by-product formed of dead microorganisms, tartaric acid, and other inorganic compounds, rich in antioxidant compounds as well as β-glucans and mannoproteins. The aim of this study was to evaluate the effect of different concentrations of Cava lees (0–2% w/w) on sourdough volatile compounds to re-valorize this by-product of the wine industry. Headspace solid-phase microextraction (HS-SPME) was optimized to study the volatile fractions of sourdoughs. The parameters selected were 60 °C, 15 min of equilibrium, and 30 min of extraction. It was found that the addition of Cava lees resulted in higher concentrations of volatile compounds (alcohols, acids, aldehydes, ketones and esters), with the highest values being reached with the 2% Cava lees. Moreover, Cava lees contributed to aroma due to the compounds usually found in sparkling wine, such as 1-butanol, octanoic acid, benzaldehyde and ethyl hexanoate.     

高效液相色谱-电感耦合等离子体质谱联用同时检测海产品中的多种有机锡

利用高效液相色谱-电感耦合等离子体质谱(HPLC-ICP/MS)联用技术对5种有机锡[三甲基氯化锡(TMT)、二丁基氯化锡(DBT)、三丁基氯化锡(TBT)、二苯基氯化锡(DPhT)和三苯基氯化锡(TPhT)]进行了分离,采用Agilent TC-C18柱进行有机锡的形态分析,流动相为V(乙腈)∶V(H2O)∶V(乙酸)=65∶23∶12,0.05%的三乙胺,pH=3.0,流速为0.4mL/min,测定了0.5~100μg/L范围内5种有机锡化合物的混合标准工作曲线,其相关系数优于0.998(R2),方法的检出限均小于0.5μg/L。采用流动相对菲律宾蛤(Ruditapes Philippi-narum,R.P.)及毛蛤(Ark Shell,A.S.)样品进行超声萃取及高速离心后,用上述方法进行了分析。结果表明,海产品含有4种有机锡,其中TBT和TPhT的含量最高,为14.38~104.7μg/L(干重)。TMT、TBT和TPhT的加标回收率均优于80%。DPhT和DBT可能存在吸附或降解问题,因而回收率仅为37.3%~75.2%。     

Enhancing effect of water vapor on the reduction of lean NOx by ethanol over an Ag/Al2O3 catalyst supported on cordierite honeycomb

The Ag/Al₂O₃ catalyst supported on cordierite honeycomb (Ag/Al₂O₃/ cordierite) is highly active forthe reduction of lean NOx by ethanol. Addition of H₂O enhances the NOx reduction to CO₂ and N₂, and suppresses the formation of by-products such as CO, CH₃CHO and C₂H₄.