利用蛋壳制备丙酸钙的研究

酸钙是我国近几年发展起来的一种新型食品防腐剂，它对霉菌、好气性芽胞杆菌、革兰氏阴性菌有很好的杀灭作用，而对酵母菌无害，而且对人体无毒、无副作用，还可以抑制黄曲霉素的产生，因而广泛用于面包、糕点等食品的防腐。据联合国粮农组织和世界卫生组织（ＦＡＯ／ＷＨ...     

气相色谱-质谱法测定化妆品中10种防腐剂

采用气相色谱-质谱法(GC-MS)同时测定化妆品中10种防腐剂含量。样品经甲醇超声提取,无水硫酸钠脱水后过滤进样检测。采用Agilent HP-5MS毛细管色谱柱(30m×0.25mm,0.25μm)分离,程序升温,分流进样进行测定。结果表明:17min内即可完成10种防腐剂的测定,各防腐剂的质量浓度均在5.00~100mg·L-1范围内与峰面积呈线性关系,方法的检出限(3S/N)为0.30~0.70ng。方法用于化妆品测定,加标回收率在96.5%~105%之间,测定值的相对标准偏差(n=6)在0.66%~3.2%之间。     

Development of a natural ingredient – Natural preservative: A case study

Lately, the cosmetic and personal care market has been more and more driven toward natural ingredients by the rising consumers' awareness about personal health and safety and their will for safer cosmetics free of harmful chemicals. Preservatives are no exception to the rule: evidence or suspicion of the toxicity of certain synthetic preservatives that have been around for decades pushed the cosmetic industry forward to seek for natural alternatives, as the selection of natural preservatives already available is quite limited. Sourcing active metabolites and developing new natural ingredients are long-term procedures that are thoroughly described in the present paper, via the example of the design of a natural preservative based on the Santolina chamaecyparissus extract, and of the assessments of its preservative effectiveness.     

Accurate screening for synthetic preservatives in beverage using high performance liquid chromatography with time-of-flight mass spectrometry

In this study, liquid chromatography time-of-flight mass spectrometry (HPLC/TOF-MS) is applied to qualitation and quantitation of 18 synthetic preservatives in beverage. The identification by HPLC/TOF-MS is accomplished with the accurate mass (the subsequent generated empirical formula) of the protonated molecules [M + H]+ or the deprotonated molecules [M − H]−, along with the accurate mass of their main fragment ions. In order to obtain sufficient sensitivity for quantitation purposes (using the protonated or deprotonated molecule) and additional qualitative mass spectrum information provided by the fragments ions, segment program of fragmentor voltages is designed in positive and negative ion mode, respectively. Accurate mass measurements are highly useful in the complex sample analyses since they allow us to achieve a high degree of specificity, often needed when other interferents are present in the matrix. The mass accuracy typically obtained is routinely better than 3 ppm. The 18 compounds behave linearly in the 0.005-5.0 mg·kg⁻¹ concentration range, with correlation coefficient >0.996. The recoveries at the tested concentrations of 1.0 mg·kg⁻¹-100 mg·kg⁻¹ are 81-106%, with coefficients of variation <7.5%. Limits of detection (LODs) range from 0.0005 to 0.05 mg·kg⁻¹, which are far below the required maximum residue level (MRL) for these preservatives in foodstuff. The method is suitable for routine quantitative and qualitative analyses of synthetic preservatives in foodstuff.     

基于改进标准加入法的碳酸饮料中防腐剂和甜味剂高通量筛查分析

利用正交设计分别配制含有三种防腐剂、四种甜味剂的模拟水样,采用核独立成分分析（KICA）处理模拟水样与加入不同含量标准品的饮料样品的紫外光谱(UV)数据,得到其中待测添加剂或背景成分的UV轮廓的独立组分(IC)信息,以IC的系数矩阵进行支持向量回归（SVR）分析,建立模拟样品中防腐剂与甜味剂的UV-KICA-SVR预测模型。添加不同含量水平添加剂的碳酸饮料样品,采用KICA处理其测试得到的UV光谱数据,得到与添加剂对应的IC信息及量,加入量与预测量线性回归方程截距即为饮料中添加剂含量。利用化学计量学“盲源信号分离”方法提取饮料样品中的待测添加剂IC信息与样品基质信息,利用SVR对解析得到的IC信号回归分析建模,改进传统单一组分测定的标准加入法,建立了碳酸饮料样品中防腐剂和甜味剂高通量筛查分析的新方法。方法用于测定碳酸饮料中山梨酸钾,苯甲酸钠、对羟基苯甲酸甲酯钠三种防腐剂与糖精钠、安赛蜜,阿斯巴甜和甘草酸铵四种甜味剂含量,检测限(LOD)为0.2～1.0 mg·L-1,测定结果与传统的色谱方法相当。     

HPLC与UPLC色谱条件转换方法研究

以分离分析化妆品中对羟基苯甲酸酯类防腐剂为内容,对HPLC和UPLC的色谱条件转换方法进行了研究。比较了采取不同方法转换得到的色谱条件参数的分离状况,选出了UPLC法最佳色谱条件。同时,用HPLC法和UPLC法对4种化妆品中的4种对羟基苯甲酸酯类防腐剂进行了定量测定,两种方法的测定结果吻合较好,相互印证了方法的准确性。     

Determination of 19 Preservatives in Various Matrices by High-Performance Liquid Chromatography

A simple and sensitive high-performance liquid chromatography (HPLC) method was developed for the determination of 19 preservatives in cosmetic matrices. The composition of the mobile phase was optimized as a gradient to achieve a lower detection limit when compared to previously validated methods, and sample preparation conditions were investigated to optimize separation of the 19 preservatives. A C18 column was used with methanol, 0.05 mol/L ammonium acetate buffer, and water as the mobile phase under gradient elution conditions. Preservatives in cosmetics were extracted with 70% methanol using an ultrasonicator, after which they were analyzed with an HPLC-photodiode array detector. All preservatives were separated within 55 min. The recoveries ranged from 94.9% to 102.8%, with relative standard deviations of less than 3.2% and no correlation coefficients lower than 0.9986. Additionally, the developed method has a low detection limit, which makes it possible to analyze trace levels of compounds in various cosmetic and ingredient matrices.     

搅拌棒吸附萃取结合气相色谱/质谱/质谱法同时测定饮料和果酱中的7种防腐剂

建立了搅拌棒吸附萃取进行前处理,气相色谱-质谱/质谱法测定饮料和果酱中7种食品防腐剂的方法.饮料和果酱样品用pH=3的30% NaCl溶液稀释,使用搅拌棒进行吸附萃取,吸附在搅拌棒上的防腐剂在热解析单元进行热解析,在冷进样口进行捕集后通过程序升温进入气相色谱,使用串联质谱的多反应监测(MRM)同时检测饮料和果酱中的7种防腐剂(苯甲酸、山梨酸以及对羟基苯甲酸甲酯、对羟基苯甲酸丙酯、对羟基苯甲酸异丙酯、对羟基苯甲酸异丁酯和对羟基苯甲酸庚酯).苯甲酸、山梨酸在40～400 mg/L浓度范围内,对羟基苯甲酸甲酯、对羟基苯甲酸丙酯、对羟基苯甲酸异丙酯和对羟基苯甲酸异丁酯在4～40 mg/L浓度范围内,对羟基苯甲酸正庚酯在0.4～4 mg/L浓度范围内,各组分响应峰面积与其相应浓度呈良好相关性,r>0.99.苯甲酸和山梨酸的检出限分别为37和47 mg/L,对羟基苯甲酸酯类为0.62～6.67 mg/L.方法的回收率为84.0%～125.0%;精确度为3.0%～18.1%.本方法灵敏度高,能够同时快速检测饮料和果酱中7种防腐剂.     

Microdistribution of copper-carbonate and iron oxide nanoparticles in treated wood

Aqueous dispersions of copper-carbonate nanoparticles and microparticles have just begun to be exploited commercially for the preservative treatment of wood. The success of the new systems will depend, in part, on the uniform distribution of the preservative in wood and the ability of copper to penetrate cell walls. We examined the distribution of copper in wood treated with a nano-Cu preservative. Copper particles are not uniformly distributed in treated wood, but they accumulate in voids that act as the flow paths for liquids in wood. Particles are deposited on, but not within cell walls. Nevertheless, elemental copper is present within cell walls, but at a lower level than that in wood treated with a conventional wood preservative. These findings suggest that nano-Cu preservatives are able to deliver bioactive components into wood cell walls even though the majority of copper particles are too large to penetrate the cell wall’s nanocapillary network.