纺织品中醛类化合物的高效液相色谱法测定

纺织品中的7种醛类化合物与2,4-二硝基苯肼在酸性条件下衍生化反应生成各自的醛腙衍生物,采用高效液相色谱-二极管阵列检测器测定了醛类化合物的含量,建立了同时测定纺织品中7种醛类化合物的检测方法。结果表明7种醛的衍生物得到良好的分离,各醛的浓度在0.15～7.5 ug/mL范围内呈现良好的线性关系,相关系数均大于0.9994,方法的平均回收率为85.4 %～97.8 %,相对标准偏差为0.2 %～7.6 %（n=7）,检出限范围为2.2～4.5 mg/kg,低于国标对相关醛类的限量要求。该方法能够满足纺织品中醛类化合物含量的测定,适用于纺织品中醛类化合物含量的分析确证。     

凝胶糖果中Vc含量检测方法比对

采用2,4-二硝基苯肼比色法与高效液相色谱法检测凝胶糖果中Vc的含量,结果发现液相色谱法测定值略小于比色法测定值。     

卷烟主流烟气中羰基化合物的改进分析方法

选择2,4-二硝基苯肼作为羰基化合物的衍生化试剂,采用高效液相色谱(HPLC)分析卷烟烟气中主要8种羰基化合物。卷烟主流烟气通过经2,4-二硝基苯肼(DNPH)酸性溶液处理的剑桥滤片进行捕集,烟气中的羰基化合物与DNPH反应生成相应的2,4-二硝基苯腙衍生物,经乙腈萃取后,采用配备紫外检测器的高效液相色谱进行定量分析。与以往的分析方法相比,该方法防止了丙烯醛衍生化合物的进一步反应,提高了分析的准确性。评价了该方法测定烟气中8种羰基化合物的重复性、回收率及检测限,采用该方法测定了肯塔基参考卷烟2R4F和部分国内外卷烟。      

柱前衍生化-高效液相色谱法测定地沟油中的脂肪醛

研究利用油脂中的不饱和脂肪酸在提炼过程中发生脂质过氧化反应、产生低分子脂肪醛的特点,采用柱前衍生化-高效液相色谱法,以2,4-二硝基苯肼为醛的衍生化试剂、2-甲基吡啶硼烷为还原剂,通过测定脂肪醛类物质来检测食用油中是否掺入了地沟油。结果表明：与食用油相比,精制地沟油中甲醛、乙醛的含量显著增加,可据此判断样品是否为地沟油。该方法专属性强、灵敏度高、准确性好,极大地优化了地沟油的检测与鉴定流程。     

高效液相色谱法测定地沟油中脂肪醛类物质

地沟油是质量极差的非食用油,若食用会严重危害人的身体健康.本文利用地沟油中存在特异性脂肪醛类物质的特点,采用2,4-二硝基苯肼作为醛的衍生试剂,应用高效液相色谱方法有效鉴别、检测精炼地沟油,并通过此方法对合格食用油进行对比测定,结果表明此方法高效、灵敏、准确,可以为有关部门加强地沟油的监督管理提供技术支持.     

气相萃取法测定皮革中乙醛含量的研究

室内装饰用皮革中的乙醛已成为消费者及行业关注的对象,相关的测试方法成为行业及企业的需求.实验中参照甲醛测定过程中所采用的水溶液萃取法及气相萃取法,基于2'4-二硝基苯肼衍生化、液相色谱法对筛选出的皮革中乙醛的含量进行测定.结果表明,水溶液萃取法未能检测出皮革中的乙醛,气相萃取法检测出样品中乙醛含量在0.7～1.8 mg...     

2,4-二硝基苯肼法测定果蔬VC含量条件探索

对2, 4-二硝基苯肼法测定果蔬VC含量的条件进行探索。结果表明,活性炭最佳用量1.8～2.2 g;显色剂2, 4-二硝基苯肼最佳用量2.0 mL,显色时间3～3.5 h;测定波长523 nm,且在2 h内吸光度无显著变化;抗坏血酸质量浓度在0～80μg/m L范围内遵守朗伯-比尔定律,表观摩尔吸光系数ε=2.455×10~3 L/(mol·cm),桑德尔灵敏度S=0.071 74。利用所得出的试验条件测定西红柿、辣椒、草莓和樱桃中VC含量,与碘量法和2, 6-二氯酚靛酚法相比,试验结果令人满意。     

气相色谱法分析卷烟烟气中的醛类化合物

本文研究了采用毛细管气相色谱仪分析卷烟烟气中醛类化合物的方法。在标准条件下吸烟,使卷烟烟气通过装有2,4-二硝基苯肼(DNPH)衍生化试剂酸性溶液的捕集装置,烟气中的醛类化合物与DNPH反应,生成稳定的2,4-二硝基苯腙衍生物,经三氯甲烷萃取,并在氮气保护下浓缩后,采用配备氮-磷检测器(NPD)的毛细管气相色谱仪进行分析。本文评价了该方法测定卷烟烟气中甲醛、乙醛和丙烯醛的重复性及回收率,并采用内标法定量测定了9种牌号卷烟烟气中的甲醛、乙醛和丙烯醛的输送量以及卷烟滤嘴对甲醛的截滤效率。采用气/联用仪(GC/S)和标样加入法鉴定出卷烟烟气中的12种醛类化合物。该方法操作简便,重复性好,回收率高,适用于卷烟烟气中醛类化合物的分析。      

自由基氧化对猪肌球蛋白-醛类化合物吸附特性的影响

采用FeCl3/抗坏血酸/H2O2羟自由基氧化体系模拟猪肌球蛋白氧化,研究不同H2O2浓度对肌球蛋白巯基总量、活性巯基、二级结构和表面疏水性的影响及与4?种典型醛类风味物质间的相互作用。结果表明：H2O2浓度对蛋白质构象有显著影响,随着H2O2浓度逐渐增加,活性巯基含量显著下降（P＜0.05）,表面疏水性显著增加（P＜0.05）。当H2O2浓度在0～5?mmol/L之间时,巯基总量、α-螺旋相对含量显著下降（P＜0.05）,蛋白质吸附能力显著增强（P＜0.05）;当H2O2浓度在5～10?mmol/L之间时,α-螺旋相对含量显著上升（P＜0.05）,蛋白质吸附能力显著减弱（P＜0.05）;当H2O2浓度在10～20?mmol/L之间时,蛋白质吸附能力显著增强（P＜0.05）。肌球蛋白与醛类化合物间的作用力主要为氢键和疏水相互作用,氢键和（或）疏水相互作用越强,蛋白质对醛类化合物吸附能力越强。     

在线衍生-双三元高效液相色谱同时检测水产品中的甲醛及双乙酸钠含量

建立采用凯氏定氮仪蒸馏,在线衍生-双三元高效液相色谱同时检测水产品中甲醛及双乙酸钠含量的方法.样品中的甲醛及双乙酸钠经磷酸酸化后采用凯氏定氮仪蒸馏提取,馏出液经双三元高效液相色谱分析,左泵系统直接检测馏出液中双乙酸钠含量,右泵系统以2,4-二硝基苯肼的乙腈-乙酸溶液为衍生液,取样液体积10 μL,衍生液体积10μL,在...     

等离子体表面改性协同静电喷雾在车饰毛织物疏水整理中的应用

为寻求更为环保的方式对羊毛／羊绒车饰品进行疏水整理,利用射频低温等离子体协同静电喷雾技术对织物进行疏水整理。通过扫描电镜观察了织物原样、等离子体处理织物、静电喷雾疏水织物和等离子体处理后静电喷雾疏水织物4种样品的表面形貌变化,采用动态接触角测量仪测试了4种样品的黏附力、静态接触角和动态接触角。结果表明：由于等离子体处理对织物表面的刻蚀作用,使后续选用静电喷雾整理的疏水剂能更有效且均匀地吸附于纤维表面;等离子体处理使织物表面黏附力提高至98.39μＮ,静态接触角减小至107.9°,接触角滞后增加至83.39°;等离子体处理协同静电喷雾疏水整理的织物具有最低的黏附力及接触角滞后,且织物透气率和透湿率仅分别下降了2.9mm／s和384g／（m2·d）,说明等离子体表面改性协同静电喷雾疏水整理具有可行性。     

一种复方天然驱蚊剂在驱蚊纺织品上的应用研究

将艾草、薄荷、桉叶、丁香粉末共混，水中煎煮提取水相物质作为驱蚊芯材。采用复相乳液聚合法，通过优化芯壁材配比、壁材的有机溶剂溶液浓度、乳化剂及用量、保护性胶体及溶液浓度、乳化剪切速度、滴加速率等因素制备驱蚊微胶囊，在粘合剂作用下整理于面料上制得驱蚊纺织品。在自制驱蚊测试箱中检测驱蚊纺织品的驱蚊率约为00％。     

涤纶窗帘布阻燃涂层整理工艺探讨

采用涂层法对涤纶窗帘布进行阻燃整理,探讨了非卤素环保型阻燃剂TEX-8或TEX-4(有机膦高聚物)与水性聚丙烯酸酯涂层胶的配伍性、比例以及阻燃涂层胶涂覆量对织物阻燃性能、断裂强力、手感的影响.研究表明:阻燃剂TEX-8与涂层胶混合后的稳定性较好,阻燃性能比TEX-4稍好,当m(阻燃剂TEX-8)∶m(涂层胶)=1∶1、涂覆量30 g/m2时,阻燃性能可达国家B1级标准,且对断裂强力和手感无明显影响.     

Comparison of a small and a large environmental test chamber for measuring VOC emissions from OSB made of Scots pine (Pinus sylvestris L.)

An investigation was undertaken to compare small environmental test chambers (23.5 L) with large ones (1 m³) for measuring the release of volatile organic compounds (VOC) from OSB made of Scots pine (Pinus sylvestris L.). Two samples were cut from one industrially manufactured OSB and were tested over a period of 45 days. Emissions are mainly composed of monoterpenes and aldehydes. Only small differences are obvious in the results acquired in both chambers. The maximum deviation of ±10% must be rather subscribed to stochastic and systematic errors of the method than to differences between both chambers. Thus, small environmental test chambers are generally suitable for measuring organic emissions from wood and wood-based products.     

基于GC-IMS技术结合多元统计模型分析不同色泽小米粥挥发性有机物差异

为探究不同色泽小米粥的风味特性,利用气相色谱-离子迁移谱（gas chromatography-ion mobility spectrometry,GC-IMS）分析市售不同色泽小米（黑、绿、白和黄）蒸煮后米粥的挥发性有机物差异。结果表明,不同色泽小米粥中共鉴定出48种挥发性有机物,其中醛类22种（占68.58%～80.66%）、酮类11种（占6.52%～9.89%）、醇类9种（占5.99%～14.91%）、呋喃类2种（占2.09%～5.66%）、酯类2种（占1.13%～1.72%）和醚类2种（占0.39%～0.69%）。不同色泽小米粥挥发性有机物以醛类、醇类和酮类为主,其次是呋喃、酯类和醚类。黑小米粥中醛类、酮类、酯类相对含量较高,绿小米粥中酮类相对含量最高;白小米粥中醇类和呋喃类相对含量最高;黄小米粥中醛类和酯类相对含量最高。主成分分析和欧氏距离分析显示,GC-IMS挥发性有机物数据可实现不同色泽小米粥样品的较好区分。通过正交偏最小二乘判别分析建立稳定性较好的预测模型,结合变量重要性投影（variable importance in projection,VIP）筛选出13种差异挥...     

Analysis,occurrence and potential sensory significance of aliphatic aldehydes in white wines

An analytical method was developed for C8–C11 aliphatic aldehydes in wine consisting of solid phase extraction (SPE) followed by multidimensional gas chromatography/mass spectrometry (MDGC/MS). The method achieves low detection limits (<30 ng L⁻¹), minimises problems of blank contamination and shows high repeatability (RSD% < 5%), but strong matrix effects were noticed during validation. These matrix effects were attributed to strong interactions between aliphatic aldehydes and other matrix elements. Three fractions were differentiated: free extractable aldehydes, aldehydes bound in hydrophilic complexes (extractable in the presence of acetaldehyde) and aldehydes bound in hydrophobic complexes (extractable in the presence of heptanal). The distribution of the three aldehyde species in wine samples was estimated using a surrogate (3,5,5-trimethylhexanal) and an internal standard (methyl phenylacetate) in double determinations (directly and after incubation with 1000 mg L⁻¹ acetaldehyde). These components had a clear additive sensory effect in mixtures and odour thresholds in wine were very low. This caused that although they were present at very low levels, in 2 out of 24 white wine samples were clearly above threshold, and in six more were at levels close to threshold. These results suggest that these components are active contributors to the citrus fruit notes of some white wines.     

TiO2 photocatalysis of natural organic matter in surface water: impact on trihalomethane and haloacetic acid formation potential

In this study, changes in the physical and structural properties of natural organic matter (NOM) during titanium dioxide photocatalytic oxidation process were investigated using several complementary analytical techniques. Potential of the treated water to form trihalomethanes (THMs) and haloacetic acids (HAAs) was also studied. High-performance size exclusion chromatography analysis showed that NOM with apparent molecular weights of 1-4 kDa were preferentially degraded, leading to the formation of lower molecular weight organic compounds. Resin fractionation of the treated water demonstrated that the photocatalytic oxidation changed the affinity of the bulk organic character from predominantly hydrophobic to more hydrophilic. Short chain aldehydes and ketones were identified by mass spectroscopy as one of the key degradation products. The addition of hydrogen peroxide to photocatalysis was found to increase the degradation kinetics but did not affect the reaction pathway, thus producing similar degradation end products. The amount of THMs normalized per dissolved organic carbon (specific THM) formed upon chlorination of NOM treated with photocatalytic oxidation was reduced from 56 to 10 microg/mg. In contrast, the specific HAAs formation potential of the treated water remained relatively unchanged from the initial value of 38 microg/mg, which could be due to the presence of hydrophilic precursor compounds that were formed as a result of the photocatalytic oxidation process.     

Fabrication of fluoropolymer-modified hydrophobic functionalization of cotton fabric by admicellar polymerization

Herein, a hydrophobic polyfluoroacrylate adhered cotton fabric having a smart affair with water under oil, is developed using a simple surfactant-assisted polymerization technique commonly known as admicellar polymerization of low surface energy trifluoroethyl acrylate monomer. The hydrophobicity of the treated substrates was determined by the contact angle. The results show that the cotton fabric became hydrophobic. The surface investigation conducted by scanning electron microscopy (SEM) provided distinctive features of the untreated and treated fabric samples. The elementary analysis was also carried out on the substrate through energy dispersive X-ray to confirm the presence of hydrophobic groups. In addition to this, the hydrophobic cotton fabric shows excellent durability against home laundering and simple adhesive peel testing.     

Evaluating competitive sorption mechanisms of volatile organic compounds in soils and sediments using polymers and zeolites

The competitive sorption of trichloroethene (TCE) and tetrachloroethene (PCE) was investigated in three natural solids, two polymers, and four zeolites. Competition was observed in natural solids with high contents of recalcitrant organic carbon, in the glassy polymer, and in zeolites with strongly and moderately hydrophobic micropores of large (7.5 x 10 A) and small pore widths (approximately 5.4 A), respectively. Isotherm results and recalcitrant OC% values for natural solids indicate that the extent of competition between TCE and PCE is related to the amount of hard organic carbon. Gas adsorption results and the variability in C/H values suggest that natural organic matter contains micropores with varying width and polarity. Isotherm results for zeolites indicate that competition between TCE and PCE increases with increasing hydrophobicity and decreasing micropore width. We suggest that competition between volatile organic contaminants in the subsurface is controlled by competition for hydrophobic micropores in hard organic matter and that smaller more hydrophobic micropores result in stronger competition.     

Sediment dilution method to determine sorption coefficients of hydrophobic organic chemicals

Sorption coefficients of hydrophobic organic chemicals (HOC) to sediments and soils can easily be underestimated in traditional batch experiments, especially because analysis of the aqueous concentration often includes compounds sorbed to colloidal organic matter. In this work, a "sediment dilution approach" has been combined with measurements of freely dissolved concentrations to determine sorption coefficients of five chlorobenzenes and two chloroanilines in spiked sediment and of two unknown chemicals in field-contaminated sediment. A range of sediment suspensions with different sediment-water ratios was made. Freely dissolved concentrations in these suspensions were measured by negligible depletion solid-phase microextraction (nd-SPME). Sediment-water sorption coefficients (KD) were derived from the decrease of the freely dissolved concentrations as a function of the "dilution factor" (DF = volume water/mass sediment). The determined sorption coefficients were very similar to literature values. The experimental setup provides sorption coefficients without the need for total extractions, and the negligible depletion SPME technique does not require phase separation. The proposed method might be an alternative for batch equilibrium experiments to determine sorption coefficients.