食品乳化剂的安全性及JECFA评价结果

FAO/WHO食品添加剂和污染物联合专家委员会(简称JECFA)是国际食品添加剂与污染物安全评价的权威机构,对世界各国所用食品添加剂的安全性进行评价。食品乳化剂是食品工业中一类重要的使用广泛的添加剂。介绍了JECFA关于食品乳化剂的主要品种及使用情况,总结了JECFA对食品乳化剂的安全性评价意见及规定标准。     

Report of progress towards the development of a performance standard for aerosol sampling instruments used in occupational hygiene

Working groups of the European Standards Organization (CEN) and the International Standards Organization (ISO) are currently jointly engaged in drafting a standard entitled ‘Assessment of the performance of instruments used for the health-related sampling of particles in workplaces’. This report describes the main requirements of the current draft standard and discusses aspects of its implementation. The author is the secretary of both the CEN and ISO working groups, and the draft standard described is the result of the collective work of the members of those working groups.     

Determining the Bio-Based Carbon Content of Surfactants

In response to a mandate from the European Commission, the European Committee for Standardization (CEN) called on the technical committee CEN/TC 276 to develop a European standard (EN 17035) to define bio-based surfactants and enable quantification of the bio-based carbon content of surfactants based on radiocarbon analyses. This analytical approach was tested through directly contracted analyses and through a round robin procedure at commercial facilities in Europe. Initial results were unsatisfactory and further investigation identified issues surrounding the degree of homogenization in the samples. In general, the samples were only homogeneous at the gram level while the maximum quantity of material that could be introduced to the analytical process was at the milligram level. Having identified the root cause of the discrepancies between measured and expected results, new samples were sent to six European laboratories. The results were satisfactory indicating linearity and accuracy across the measurement range.     

Determination of aniline and its derivatives in environmental water by capillary electrophoresis with on-line concentration

This paper describes a simple, sensitive and environmentally benign method for the direct determination of aniline and its derivatives in environmental water samples by capillary zone electrophoresis (CZE) with field-enhanced sample injection. The parameters that influenced the enhancement and separation efficiencies were investigated. Surprisingly, under the optimized conditions, two linear ranges for the calibration plot, 1-50 ng/mL and 50-1000 ng/mL (R > 0.998), were obtained. The detection limit was in the range of 0.29-0.43 ng/mL. To eliminate the effect of the real sample matrix on the stacking efficiency, the standard addition method was applied to the analysis of water samples from local rivers.     

Simultaneous determination of oil and water contents in different oilseeds by pulsed nuclear magnetic resonance

Routine analysis of oil and water contents in different oilseeds with the Bruker Minispec pulsed nuclear magnetic resonance (NMR) analyzer (Bruker Analytische Mestechnik, Rheinstetten, Germany) is rapid (16 s measurements), precise, accurate and nondestructive. In 1991, subcommittee SC2 (oil seeds) of the Technical Committee Number 34 [organized by the International Standards Organization (ISO), Geneva, Switzerland] organized an international collaborative study for pulsed NMR analysis of oil content in whole rapessed. An additional study was performed in 1993 to extend the method to sunflower, linseed and soy seeds. The Draft International Standard ISO DIS/10565 (Draft International Standards, International Standards Organization, Geneva, 1993) describes the procedure of the pulsed NMR method for determination of oil content in rapeseed and presents the interlaboratory comparison results based on the calculations described in the Normative ISO 5725 (Draft International Standards, International Standards Organization, Geneva, 1993). The standard was approved in 1992 and will be published in 1993. The interlaboratory collaborative studies showed that the analyses of oil and moisture by pulsed NMR were either comparable or more repeatable than measurements done by the traditional methods. No statistical differences between determinations by the traditional and pulsed NMR methods were found. Simultaneous determination of percent moisture and percent oil content in whole seeds is possible with pulsed NMR by the spin-echo method. In addition, multiple components of the oil can be detected and quantitated by T2 analysis from the Carr-Purcell-Meiboom-Gill pulse sequence. The instrument is easy to calibrate with whole oilseeds, and the calibration can be checked periodically with the same seeds because the measurement is nondestructive. Pulsed NMR provides a rapid alternative to the long, laborious, traditional methods of analysis and offers substantial long-term savings of both time and money. Minimal operator training is required once the technique has been established for routine use. Presented at the 84th AOCS Annual Meeting & Expo, April 27, 1993, Anaheim, California.     

Bauer mill operation and its effect on the percentage of oil found in soybeans

Summary and Conclusions A Bauer Mill officially approved by the A.O.C.S. for grinding samples of soybeans to be used for oil determinations was used to grind duplicate series of the 10 check samples of soybeans sent out each year by the Smalley Foundation Committee. When the mill was operated at high temperature and forced to grind at its maximum rate, the 10 samples averaged 18.03% of oil. A duplicate series of 10 samples ground in a water-cooled mill at about one-half the maximum possible rate of grinding for the mill averaged 17.57% oil. Improper operation of a Bauer Mill when preparing soybean seed samples for analysis can cause abnormally high oil percentages. A simple mechanical device to reduce the rate of feed is suggested for use with the mill. A Bauer Mill is satisfactory for use in grinding samples of soybeans for oil analysis when it is properly operated. Division of Forage Crons and Diseases, Bureau of Plant Industry, Solis and Agricultural Engineering, Agricultural Research Administration, U. S. Department of Agriculture. Publication No. 234 of the U. S. Regional Soybean Laboratory, Urbana, Illinois.     

近红外光谱用于火箭煤油馏程测定的研究

利用近红外光谱法及标准方法对60个火箭煤油样品的馏程进行测定,采用偏最小二乘法建立模型,初馏点与10%馏程的相关系数分别达到0.9299、0.9584。用该模型对10个未知样品进行测定,近红外光谱法预测结果与实测结果相关性很好,其准确度和再现性均符合标准分析方法的要求,表明近红外光谱分析技术代替传统标准方法快速测定火箭煤油馏程是可行的。     

The calculation of weight factors for tristimulus integration

This article defines the method of calculation of weight sets for tristimulus integration published by the ASTM in its Method E 308–85. The preparation of weight sets for any measurement interval or wavelength range by Lagrange cubic interpolation from standard tables of data at other intervals is described. In addition, methods of truncating weight sets to wavelength ranges of less than 360 nm to 830 nm are discussed. The importance of calculating and maintaining the chromaticity of the neutral point is noted. An example of calculation of a set of weights is given in an Appendix, along with an example computer program that will calculate a set of weights at 20 nm intervals from standard illuminant-observer data given at 1 nm intervals.     

液相色谱-串联质谱法测定人血浆中左旋氨氯地平

建立一种快速灵敏的液相色谱-串联质谱方法测定人血浆中左旋氨氯地平。分析样品经液-液萃取后,通过Zorbax SB C18柱进入质谱,内标为尼莫地平。标准曲线的线性范围0．05～20ng／mL,日内日间精密度小于7．4％,准确度在±1．1％之间,该方法成功应用于22名健康受试者口服5mg左旋氨氯地平的药动学研究。     

The AOCS smalley program

This program is named for Frank N. Smalley, a charter member of AOCS. In 1909, he was chief chemist for the Southern Cotton Oil Company, the same year in which AOCS was formed. Smalley checked the proficiency of his firm’s laboratories by distributing weekly meal samples that had been prepared in his Savannah laboratory. Other analytical chemists saw the value of such a program and asked to participate. In 1915, the Uniform Methods Committee, under Dr. Smalley, adopted this program. In 1955, the name was formally shortened to the Smalley Committee. It continues to function largely with the aid of volunteer help. AOCS is greatly indebted to the people and industries who give of their time and talents. In 1981, an ad-hoc committee reviewed the Smalley Committee and each of the series involved and declared the program was functioning well and carrying out its intended purpose.     

Influence of grease formulation parameters on the tribological property of rice bran oil based lubricating grease

The negative environmental impacts and depletion of resources caused due to the excess usage of petroleum based products made researchers to think about an alternative biodegradable product. In the present study, rice bran oil (RBO) was used as a base oil for formulating 16 different grease samples. The thickener used was generated in situ by mixing 12-hydroxy stearic acid (12 HSA) to calcium hydroxide at a different ratio from 1.25 to 2. The formulation parameters such as weight % of thickener, saponification time, and maximum temperature spanned the ranges 5–11 wt.%, 1–2.5 h, and 150–180°C, respectively. The tribological properties such as wear scar diameter (WSD) and friction of 16 different grease samples formulated by varying these parameters were evaluated using a standard four-ball tester as per ASTM standards. The grease samples were characterized by evaluating the penetration value using a standard cone penetrometer. The influence of these formulation parameters on the experimentally evaluated properties was also examined in this work. The results indicated that the variation of these parameters during grease formulation has a significant influence on the evaluated properties.     

NLD系列阻燃剂的气相色谱分析

本文研究了NLD系列阻燃剂的气相色谱分析方法。采用双火焰光度检测器,选择最佳色谱操作条件。并以磷酸三丁酯为内标物,连行了内标去定量。实验结果表明,NLD—01型阻燃剂和NLD—02型阻燃剂的线性范围分别为0.4～1.0mg/ml和0.2～0.5mg/ml。用本文所研究的方法,测试了不同批号的阻燃剂试样,其相对标准偏差均小于2%。     

碳酸根型镁铝复合氢氧化物的合成和表征及其催化性能

以恒定pH值共沉淀法合成碳酸根型镁铝水滑石,用XRD、IR、TG-DTA和SEM等手段进行表征。XRD衍射表明，Mg与Al物质的量比为1∶1、3∶1、4∶1和6∶1的合成物均有水滑石结构。热重-差热分析(TG-DTA)显示，水滑石有两个吸热峰值:第一吸收峰值在200～250 ℃, 第二吸热峰值在400～450 ℃,最大损失重量在2780%～33.41%。SEM分析可知，样品呈层状、棒状、针状和蜂窝状等结构。并对镁铝复合氢氧化物作为催化剂用于生物柴油制备作了研究。结果表明，Mg与Al物质的量比为3∶1的水滑石可使甲酯收率达到90%左右，且可重复使用。产品达到德国生物柴油质量标准。     

Quantitative assessment of relationship between pressure performances and material mechanical properties of medical graduated compression stockings

Graduated compression stockings (GCSs) have been widely applied for prophylaxis and treatment of venous disorders. Their pressure performances and medical functions depend largely upon the mechanical properties of stocking knitted fabrics. In the present study, the multiple fabric mechanical behaviors of GCSs with different pressure levels and medical functions were examined by using Kawabata standard evaluation system. On the basis of pressure ranges advised by the European Committee for Standardization, the definitive quantitative relationships between pressure performances and key mechanical properties of GCS fabrics were developed and evaluated. The results show that GCS fabrics with different pressure performances produced significant differences in tensile, shearing, and bending properties (P < 0.001). GCS fabrics generating lighter pressure possessed higher values in tensile strain, tensile energy at a given force, and lower values in shearing stiffness and bending rigidity, while stronger pressure levels are produced by the GCS fabrics with higher resistance to the mechanical deformations. Pressure magnitude performances of GCSs are an integrative action performed by multiple fabric mechanical properties. The developed relationships between pressure levels and material mechanical properties provide a rational and practical approach for assessing and predicting pressure functional performances of GCSs. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 601–610, 2007     

Formulations for the OSA uniform color scales committee samples

Pigment formulations used in producing the 558 samples illustrating the OSA Uniform Color Scales Committee color space are presented. The 15 pigments used, never more than four at a time, are identified and calibration data for computer formulation are given. The information should allow the reproduction of close approximations to the original OSA samples.     

氟啶胺在菊花中的残留消解动态及其风险评估

[目的]建立了菊花中氟啶胺的液相色谱-串联质谱(QuEChERS-UPLC-MS/MS)分析方法,并在安徽、浙江、江苏和广西4地进行了500 g/L氟啶胺悬浮剂在菊花上残留的田间试验,研究了氟啶胺在菊花中的消解动态和最终残留量,并对菊花中氟啶胺可能产生的膳食摄入风险进行了评估。[方法]菊花样品经乙腈提取,以C18色谱柱分离待测物,采用ESI源,负离子模式和多反应监测模式(MRM)检测,外标法定量。[结果]在0.001~1.0 mg/L质量浓度范围内氟啶胺线性关系良好,相关系数大于0.9936;在0.010、0.10、0.50 mg/kg 3个质量分数下,菊花中氟啶胺的回收率为81.4%~92.5%,相对标准偏差(RSD)为1.6%~6.4%,检出限(LOD)为0.011~0.040μg/kg,方法定量限(LOQ)为添加的最低质量分数0.010 mg/kg。田间试验结果表明:氟啶胺在菊花中消解符合一级反应动力学方程,半衰期为3.5~3.9 d,属易降解农药;使用500 g/L氟啶胺悬浮剂,施药剂量300~450 g a.i./hm2,分别施药2、3次,距末次施药后14 d,菊花鲜样的残留量低于同期干样的残留量。[结论]膳食摄入风险评估结果表明:氟啶胺的风险概率为每人每日摄入总量的77%,表明在菊花生长期间按照推荐剂量使用氟啶胺对消费者的膳食健康风险较低,对消费者健康是安全的。     

Determination of olive oil free fatty acid by fourier transform infrared spectroscopy

A new procedure for determining free fatty acids (FFA) in olive oil based on spectroscopic Fourier transform infrared-attenuated total reflectance spectroscopy measurements is proposed. The range of FFA contents of samples was extended by adding oleic acid to several virgin and pure olive oils, from 0.1 to 2.1%. Calibration models were constructed using partial least-squares regression (PLSR). Two wavenumber ranges (1775–1689 cm⁻¹ and 1480–1050 cm⁻¹) and several pretreatments [first and second derivative; standard normal variate (SNV)] were tested. To obtain good results, splitting of the calibration range into two concentration intervals (0.1 to 0.5% and 0.5 to 2.1%) was needed. The use of SNV as a pretreatment allows one to analyze samples of different origins. The best results were those obtained in the 1775–1689 cm⁻¹ range, using 3 PLSR components. In both concentration ranges, at a confidence interval of α = 0.05, no significant differences between the reference values and the calculated values were observed. Reliability of the calibration vs. stressed oil samples was tested, obtaining satisfactory results. The developed method was rapid, with a total analysis time of 5 min; it is environment-friendly, and it is applicable to samples of different categories (extra virgin, virgin, pure, and pomace oil).     

Short Communication: Aircraft interior panels tested according to the maritime high-speed craft code

The fire standard for aircraft interior panels has been compared to the corresponding marine standard with respect to smoke emission and heat release rate. This has been performed by testing an aircraft panel approved by the Federal Aviation Administration according to one of the International Maritime Organization standards for High-Speed Craft, according to the full-scale room fire test, ISO 9705. The test showed that even if the panel met the strict requirements of the Federal Aviation Administration it did not fulfil the apparently even stricter requirements of the International Maritime Organization. The panel failed on several accounts, including smoke production, heat release and structural integrity. © 1997 John Wiley & Sons, Ltd.     

A simple,graphic procedure for authentication of commercial fats and oil based on fatty acid compositions in codex standards

It is likely that fatty acid compositions as derived by gas liquid chromatography will soon become one of the mandatory criteria for authentication of individual (unmodified) commercial fats and oils in the standards of the Food and Agriculture Organization/ World Health Organization’s Codex Alimentarius Committee on Fats and Oils. A simple graphical procedure for using the Codex Committee’s fatty acid composition standards to identify fats and oils has been devised and tested. Except for one sample, the fatty acid-based standards have not been found to conflict with some presently accepted mandatory standards (i.e, iodine value, refractive index, and saponification value).     

Determination of water in cooked cottonseed meats by a modified indirect conductivity method

Summary The modified indirect conductivities and oven-dry moisture percentages were determined on mine Samples of cooked cottonseed meats (1.8 to 13.9% water). Statistical treatment of the data yields the following results: (1) equation of the regression line, {fx177-1} (2) correlation coefficient, 0.998; (3) standard deviation from the regression line, 0.27% water. Ten replicate determinations made on each of two samples containing 2.7 and 7.7% water showed standard deviations of 0.07 and 0.08% water. These results show that the accuracy and precision of the modified indirect conductivity method are satisfactory for practical applications. For a consecutive series of determinations the average time required per determination was about 9 min. This time could be reduced to about 5 min. by using duplicate sets of stirring apparatus. Describes data obtained in research conducted cooperatively by the Cotton Research Committee of Texas and the Texas Engineering Experiment Station.