中国食品添加剂法典委员会专家组会议在京召开

本刊北京讯:为更好地了解国际食品法典委员会CAC有关《食品添加剂通用法典标准》(GSFA),开好“国际食品添加剂法典会议”和“国际食品污染物会议”,2007年2月2日由中国疾病预防控制中心营养与食品安全所在北京广西大厦组织召开了“中国食品添加剂法典委员会专家组会议”。会议特别邀请了国际食品添加剂法典委员会秘书处(CCFA)工作组主席KAREN.HULEBAD,SE.D.和美国食品药品管理局专家DENNIS M.KEEFE,PH.D,,出席会议的中方专家组成员有CCFA秘书处负责人刘秀梅教授,CCFA秘书处顾问阚学贵,中国食品添加剂协会常务副理事长兼…     

第49届国际食品添加剂法典委员会会议进展

正2017年3月20日至24日,第49届国际食品添加剂法典委员会(CCFA)会议在澳门举行,国际食品添加剂通用标准(GSFA)工作组会议在3月17~18日举行。来自50个成员国和1个成员组织(欧盟)及32个国际组织的260余名代表参加了本届会议,另有50余名来自食品生产加工行业的代表旁听了会议。此次会议是中国担任CCFA会议主持国以来主办的第11次会议,会议由国家卫生和计划生育委员会主办,国家食品安全风险评估中心承办,澳门民政总署协办。国家食品安全风险评估中心总顾问、CCFA主席     

2007年国际食品添加剂法典委员会最新进展

食品添加剂国际法典委员会第39届会议于2007年4月24日至28日在北京召开,代表56个成员国、1个成员组织及29个国际组织的232名代表参加了会议,本届会议讨论了国际食品添加剂标准化领域的15个议题,现就主要议题的背景及最新进展情况介绍如下:一、将商品标准中的食品添加剂纳入到食     

第51届国际食品添加剂法典委员会会议在济南举行

<正>本刊济南讯:2019年3月25日-29日,第51届国际食品添加剂法典委员会(CCFA)会议在济南召开。来自48个成员国和1个成员组织(欧盟)及33个国际组织的300余名代表参加了本届会议。国际食品法典委员会(CAC)是由联合国粮农组织(FAO)和世界卫生组织(WHO)共同建立,以保障消费者的健康和确保食品贸易公平为宗旨的一个制定国际食品标准的政府间组织。我国于1984年正式加入CAC并成立由原卫生部任组长的中国食品法典委员会,我国2006年成功当选国际食品添加剂法典委员会(CCFA)主持国,成为首个承     

第五十届国际食品添加剂法典委员会(CCFA)会议进展

正2018年3月26日至30日,第50届国际食品添加剂法典委员会(CCFA)在中国厦门召开。会议讨论的主要议题及进展情况如下:一、通过大会会议议程(议题1)委员会一致通过会议议程,并同意成立以下会间工作组,所有国家成员和观察员均可参加,并以英语为工作语言:(一)认可和协调一致工作组,讨论法典商品标准中食品添加剂使用规定和食品添加剂通用     

参加国际食品添加剂和污染物法典委员会第32届会议的情况汇报

国际食品添加剂和污染物法典委员会(下简称"CCFAC")第32届会议于2000年3月20-24日在中国北京召开.来自全球40个成员国和31个国际组织的284名代表参加了全体会议.卫生部副部长殷大奎出席了开幕式并致辞.中国组成了由卫生部法制监督司副司长赵同刚为团长,10个部委代表、有关专家和香港特别行政区代表共50人的代表团参加了会议以及会前的3个工作组(添加剂标准(GSFA)特别工作组、添加剂规格特别工作组以及污染物和毒素特别工作组)会议.现将此次会议的有关情况汇报如下:     

第四十届国际食品添加剂法典委员会进展及其对我国食品添加剂管理的影响

第四十次国际食品添加剂法典委员会（CCFA）于2008年4月21～25日在北京召开,中国疾病预防控制中心营养与食品安全所的陈君石院士作为主席主持会议,参会代表来自63个成员国和1个成员组织,29个作为观察员的国际组织。卫生部陈啸宏副部长到会并致辞,他指出,食品安全已经超越国家政府的界线成为全球性问题,并强调了本委员会在食品添加剂领域的重要作用。陈副部长强调,中国基于食品添加剂法典通用标准（GSFA）修订了中国的食品添加剂标准及食品添加剂使用情况的监测在食品添加剂管理中的重要性,并承诺卫生部对CCFA未来工作的支持。     

第49届国际食品添加剂法典委员会(CCFA)会议在澳门举行

<正>本刊澳门讯:2017年3月17日至24日,第49届国际食品添加剂法典委员会(CCFA)会议在澳门举行。来自50个成员国和1个成员组织(欧盟)及32个国际组织的260余名代表参加了本届会议。国际食品法典委员会(CAC)是由联合国粮农组织(FAO)和世界卫生组织(WHO)共同建立,以保障消费者的健康和确保食品贸易公平为宗旨的ー个制定国际食品标准的政府间组织。我国于1984年正式加入CAC并成立由原卫生部任组长的中国食品法典委员会,我国2006年成功当选国际食品添加剂法典委员会(CCFA)主持国,成为首个承担综合委员会的发展中国家。CCFA具体负责食品添加剂、食用香精香料、     

第42届国际食品添加剂法典委员会(CCFA)会议在京召开

本刊记者北京讯:2010年3月15～19日,第42届国际食品添加剂法典委员会(CCFA)会议在北京昆仑饭店举行,会议由国际食品添加剂法典委员会主席、中国疾病预防控制中心陈君石院士主持,来自58个成员国家及26个国际组织的200余位代表和观察员出席了会议,本次会议也是中国以主持国身份连续四次主办国际食品添加剂法典委员会大会.     

第51届国际食品添加剂法典委员会进展

<正>第51届国际食品添加剂法典委员会(Codex Committee on Food Additives,CCFA)会议于2019年3月25日至29日在山东省济南市召开,会议由国家食品安全风险评估中心樊永祥研究员主持,来自48个成员国、1个成员组织(欧盟)和33个观察员组织参加了此次会议。国际食品添加剂通用标准(General Standards on     

Arsenic(III) oxidation by iron(VI) (ferrate) and subsequent removal of arsenic(V) by iron(III) coagulation

We investigated the stoichiometry, kinetics, and mechanism of arsenite [As(III)] oxidation by ferrate [Fe(VI)] and performed arsenic removal tests using Fe(VI) as both an oxidant and a coagulant. As(III) was oxidized to As(V) (arsenate) by Fe(VI), with a stoichiometry of 3:2 [As(III):Fe(VI)]. Kinetic studies showed that the reaction of As(III) with Fe(VI) was first-order with respect to both reactants, and its observed second-order rate constant at 25 degrees C decreased nonlinearly from (3.54 +/- 0.24) x 10(5) to (1.23 +/- 0.01) x 10(3) M(-1) s(-1) with an increase of pH from 8.4 to 12.9. A reaction mechanism by oxygen transfer has been proposed for the oxidation of As(III) by Fe(VI). Arsenic removal tests with river water showed that, with minimum 2.0 mg L(-1) Fe(VI), the arsenic concentration can be lowered from an initial 517 to below 50 microg L(-1), which is the regulation level for As in Bangladesh. From this result, Fe(VI) was demonstrated to be very effective in the removal of arsenic species from water at a relatively low dose level (2.0 mg L(-1)). In addition, the combined use of a small amount of Fe(VI) (below 0.5 mg L(-1)) and Fe(III) as a major coagulant was found to be a practical and effective method for arsenic removal.     

Iron(VI) and iron(V) oxidation of copper(I) cyanide

Copper(Il) cyanide (Cu(CN)4(3-)) in the gold mine industry presentsthe biggest concern in cyanide management because it is much more stable than free cyanide. Cu(CN)4(3-) is highlytoxic to aquatic life; therefore, environmentally friendly techniques are required for the removal of Cu(CN)4(3-) from gold mine effluent. The oxidation of Cu(CN)4(3-) by iron-(VI) (FeVIO4(2-), Fe(VI)) and iron(V) (FeVO4(3-), Fe(V)) was studied using stopped-flow and premix pulse radiolysis techniques. The stoichiometry with Fe(VI) was determined to be 5HFeO(4-) + Cu(CN)4(3-) + 8H2O - > 5Fe(OH)3 + Cu2+ + 4CNO- +3/202 + 6OH-. The rate law for the oxidation of Cu(CN)4(3-) by Fe(VI) was found to be first-order with each reactant. The rates decreased with increasing pH and were mostly related to a decrease in concentration of reactive protonated Fe(VI) species, HFeO4-. A mechanism is proposed that agrees with the observed reaction stoichiometry and rate law. The rate constant for the oxidation of Cu(CN)4(3-) by Fe(V) was determined at pH 12.0 as 1.35 +/- 0.02 x 10(7) M(-1) s(-1), which is approximately 3 orders of magnitude larger than Fe(VI). Results indicate that Fe(VI) is highly efficient for removal of cyanides in gold mill effluent.     

表没食子儿茶素没食子酸酯的甲基化分子修饰

研究表没食子儿茶素没食子酸酯(EGCG)的甲基化分子修饰。以碘甲烷作为甲基供体,采用化学合成方法研究EGCG 的甲基化分子修饰,并通过HPLC-MS 和NMR 等对反应产物进行结构鉴定。结果表明：采用化学合成方法能有效完成EGCG 的甲基化分子修饰,并分离鉴定出5 个EGCG 甲基化衍生物,分别为4″-Me-EGCG、4′,4″-di-Me-EGCG、5,3′,4′,5′,3″,4″,5″-hepta-Me-EGCG、5,7,3′,4′,3″,4″,5″-hepta-Me-EGCG、5,7,3′,4′,5′,3″,4″,5″-octa-Me-EGCG。     

Reduction of Tc(VII) by Fe(II) sorbed on Al (hydr)oxides

Under oxic conditions, Tc exists as the soluble, weakly sorbing pertechnetate [TcO4-] anion. The reduced form of technetium, Tc(IV), is stable in anoxic environments and is sparingly soluble as TcO2 x nH2O(s). Here we investigate the heterogeneous reduction of Tc(VII) by Fe(II) adsorbed on Al (hydr)oxides [diaspore (alpha-AlOOH) and corundum (alpha-Al2O3)]. Experiments were performed to study the kinetics of Tc(VII) reduction, examine changes in Fe surface speciation during Tc(VII) reduction (M?ssbauer spectroscopy), and identify the nature of Tc(IV)-containing reaction products (X-ray absorption spectroscopy). We found that Tc(VII) was completely reduced by adsorbed Fe(II) within 11 (diaspore suspension) and 4 days (corundum suspension). M?ssbauer measurements revealed thatthe Fe(II) signal became less intense with Tc(VII) reduction and was accompanied by an increase in the intensity of the Fe(III) doublet and magnetically ordered Fe(III) sextet signals. Tc-EXAFS spectroscopy revealed that the final heterogeneous redox product on corundum was similar to Tc(IV) oxyhydroxide, TcO2 x nH2O.     

Mind the (yield) gap(s)

This paper explores the origin of the notion of ??yield gap?? and its use as a framing device for agricultural policy in sub-Saharan Africa. The argument is that while the yield gap of policy discourse provides a simple and powerful framing device, it is most often used without the discipline or caveats associated with the best examples of its use in crop production ecology and microeconomics. This argument is developed by examining how yield gap is used in a selection of recent and influential agricultural policy documents. The message for policy makers and others is clear: ??mind the (yield) gap(s)??, for they are seldom what they appear.     

Reactivity of Pb(II) at the Mn(III,IV) (oxyhydr)oxide--water interface

In this study, the reactivity of lead (Pb(II)) on naturally occurring Mn(III,IV) (oxyhydr)oxide minerals was evaluated using kinetic, thermodynamic, and spectroscopic investigations. Aqueous Pb(II) was more strongly adsorbed to birnessite (delta-MnO1.7) than to manganite (gamma-MnOOH) under all experimental conditions. The isoteric heat of Pb adsorption (delta HT) or birnessite was 94 kJ mol-1 at a surface loading of 1.1 mmol g-1, and decreased with increasing adsorption density. This indicated that adsorption was an endothermic process and that birnessite possessed heterogeneous sites of reactivity for Pb. X-ray absorption fine structure (XAFS) spectra revealed that Pb was adsorbed as inner-sphere complexes on both birnessite and manganite with no evidence to suggest oxidation as an operative sorption mechanism. Lead appeared to coordinate to vacancy sites in the birnessite layer structure with concurrent release of Mn to solution, which resulted in a greater number of second shell Mn scatterers in Pb-birnessite when compared to Pb-manganite samples. The difference in Pb coordination apparently explained the contrasting desorption behavior between the two Mn minerals. These results have significant implications for Pb partitioning in soil environments containing solid-phase Mn(III,IV) (oxyhydr)oxides.     

Iron(VI) and iron(V) oxidation of thiocyanate

Thiocyanate (SCN-) is used in many industrial processes and is commonly found in industrial and mining waste-waters. The removal of SCN- is required because of its toxic effects. The oxidation of thiocyanate (SCN-) by environmentally friendly oxidants, Fe(VI) and Fe(V), has been studied anaerobically using stopped-flow and premix pulse radiolysis techniques. The stoichiometry with Fe(VI) was determined to be 4HFeO(4-) + SCN(-) + 5H2O-->4Fe(OH)3 + SO4(2-) + CNO(-) + O2 + 2OH-. The rate law for the oxidation of SCN- by Fe(VI) was found to be -d[Fe(VI)]/dt = k11([H+]/([H+] + Ka,HFeO4)) [Fe(VI)][SCN-] where k11 = 2.04 +/- 0.04 x 10(3) M-1 s-1 and pKa,HFeO4 = 7.33. A mechanism is proposed that agrees with the observed reaction stoichiometry and rate law. The rate of oxidation of SCN- by Fe(V) was approximately 3 orders of magnitude faster than Fe(VI). The higher reactivity of Fe(V) with SCN- indicates that oxidations by Fe(VI) may be enhanced in the presence of appropriate one-electron-reducing agents. The results suggest that the effective removal of SCN- can be achieved by Fe(VI) and Fe(V).     

Supercritical fluid extraction (SFE) of 4(5)-methylimidazole (4-MeI) and 2-acetyl-4(5)-(1,2,3,4)-tetrahydroxybutyl-imidazole (THI) from ground-coffee with high-performance liquid chromatographic-electrospray mass spectrometric quantification (HPLC/ESI-MS).

Two polar analytes, 4(5)-methylimidazole (4-MeI) and 2-acetyl-4(5)-(1,2,3,4)-tetrahydroxybutyl-imidazole (THI), were extracted with supercritical carbon dioxide (CO2) modified with aqueous methanol. The method was applied to a roasted coffee powder with good recovery rates. Method efficiency was compared with that of solid-phase extraction using SCX Disc cartridges and validated for spiked solid matrix. The analytes were determined using isocratic liquid chromatography-mass spectrometry (LC/MS) on an Atlantis HILIC Silica column (150 x 2.1 mm, 3 microm) with 80% methanol and 20% 0.01 mol l-1 ammonium formate as the mobile phase. The limit of quantification was around 1.5 pg for 4-MeI and 2.0 pg for THI. The linearity of the calibration curves was satisfactory as indicated by correlation coefficients of >0.999. The coefficient of variation for the intra-day and inter-day precisions was <4% (n = 6). Accuracy was in the range 98-101%; recovery rates were > or = 98 and > or = 99% for THI and 4-MeI, respectively. Several samples of Arabica coffee from various locations and commercially available 'off-the-shelf' coffee products (Arabica/Robusta mixtures) were analysed to test the method.     

Attractancy of diethyl ether extracts of Arachis hypogaea (Linnaeus) (Papilionaceae), Citrullus lanatus (Thunberg) (Cucurbitaceae) and Irvingia gabonensis var. excelsa (Baillon) (Irvingiaceae) to Oryzaephilus mercator (Fauvel) (Coleoptera: Silvanidae)

Volatiles of the diethyl ether extracts of I. gabonensis, C. lanatus and A. hypogaea attracted 1–7 and 28–42-day-old adult O. mercator when tested in a two-choice pitfall Petri dish bioassay. For both age groups, a significant difference was observed in response between fed and starved adults to the different extracts. Differences in starvation time did not affect responses of individuals in the 1–7-day-old group; a significant effect was observed in the 28–42-day-old group.

Adults, 28–42-day-old were significantly more responsive to virtually all extracts than 1–7-day-old adults. Responses of adults in each age group to the different extracts were not significantly different. The time of trial within the period 0900–1900 h did not significantly affect the response of adults in both age groups, starved for 2 days, to any extract.     

羟丙基壳聚糖亚铁配合物的合成

采用壳聚糖先与Fe2+配合,再用环氧丙烷改性,研究了羟丙基壳聚糖-Fe2+的合成工艺,并用紫外和红外光谱对衍生物结构进行了表征。结果表明,在壳聚糖用量为0.1g、Fe2+起始浓度为16mg/mL、溶液pH为2的条件下,制得壳聚糖亚铁配合物。接着在壳聚糖-Fe2+∶环氧丙烷∶25%四甲基氢氧化铵为1mg∶10mL∶0.8mL条件下,制得羟丙基壳聚糖-Fe2+(HPCS-Fe2+)。位于1160～1030cm-1处有特征吸收峰,说明衍生化后得到的HPCS和HPCS-Fe2+上两个羟基上都发生了反应。