活性炭去除饮用水突发性污染桔霉素的研究

本文研究不同浓度桔霉素对饮用水p H值、折射率、电导率、旋光性变化的影响以及探讨活性炭对饮用水中可能发生的突发性污染物桔霉素的去除工艺效果,为饮用水突发安全事件应急处理提供技术支撑。桔霉素在1 mg/L~50 mg/L范围内,饮用水p H显著下降,折射率呈线性增大。桔霉素在0.1 mg/L~10 mg/L范围内,饮用水电导率显著增强,但桔霉素没有旋光性。桔霉素对p H、折射率、电导率影响情况可作为饮用水中桔霉素污染与否的参考指标。两种形态的活性炭比较试验结果,粉末活性炭去除桔霉素的效果优于颗粒活性炭。粉末活性炭去除饮用水中桔霉素突发性污染的最优工艺参数为:活性炭添加量0.8 g/L,时间5 min,去除率达到109.86%。粉末活性炭去除桔霉素快速高效,可用于饮用水桔霉素突发性污染事件的快速应急处理。     

离子色谱检测生活饮用水中的溴酸盐

正在使用臭氧深度处理饮用水过程中,臭氧会将水体中自然存在的溴化物氧化为对人体有害的溴酸盐。已有研究证明,溴酸盐具有致癌、致畸、导致肾病和强烈的生殖性毒性,还会导致DNA的损伤。因此世界卫生组织(WHO)曾建议饮用水中溴酸盐的含量应控制在25μg/L以下,美国国家环保局(USEPA)和欧盟(EU)则要求用臭氧处理的饮用水中的溴酸盐浓度必     

离子色谱法测定包装饮用水中的溴酸盐

对包装饮用水中的溴酸盐含量的测定方法进行研究,在现行国标的基础上,优化了色谱测定条件,并进行了方法学考察。该方法在5.00~100μg/L范围内线性关系良好(r=0.999 8),方法检出限为0.031 8μg/L,回收率为99.9%~102.5%(加标浓度25.25,50.50和75.75μg/L),重复性(n=6)为0.35%。并对乐山地区超市包装饮用水进行随机抽样调查,试样测定值在1.55~6.91μg/L之间,按GB 19298—2014限量要求(0.01 mg/L),均无过量添加。离子色谱法测定包装饮用水中的溴酸盐具有操作简便,灵敏度、准确度高,分离效果好,重现性佳等特点,可有效满足检验检测部门对包装饮用水中溴酸盐的测定。     

活性炭控制矿泉水中溴酸盐的选型及效果研究

为控制矿泉水中的溴酸盐含量,采用活性炭(GAC)技术对矿泉水和超纯水中的溴酸盐进行小试研究,同时根据碘吸附值和其溴酸盐控制能力进行GAC的选型,并进行中试实验,研究GAC对溴酸盐的去除效果。结果表明,当空床接触时间(EBCT)为5min时,矿泉水和超纯水中溴酸盐浓度均降至10μg·L-1以下。12种GAC的碘吸附值不同,GAC1、GAC2、GAC3和GAC4对溴离子和溴酸盐吸附结果显示,GAC1对水中溴离子去除效果最好,可以用于控制溴酸盐的生成;GAC2对水中溴酸盐去除效果最好,可以用于降低生成后溴酸盐含量。中试结果显示,臭氧化过程中生成的过量溴酸盐经GAC吸附,其含量可以降低至5μg·L-1以下。     

仪器分析技术在矿泉水及包装材料分析中的新进展

我国的自来水等城镇供水的消毒方式主要以二氧化氯消毒为主,但是瓶装水的消毒则有部分采用臭氧消毒。溴酸盐是用臭氧对饮用水进行消毒时产生的一种消毒副产物。研究表明,当人们终身饮用含溴酸盐为5．0μg／L或0．5μg／L的饮用水时,其致癌率分别为10^-4和10^-5。由于溴酸盐的致癌作用,各国政府和国际组织对溴酸盐的毒性给予了极大关注,对饮用水中的溴酸盐进行了大规模的研究,并且制定了饮用水中溴酸盐的最大容许浓度。     

分析离子色谱法测定饮用水中痕量亚硝酸盐和溴酸盐

应用离子色谱法测定饮用水中痕量亚硝酸盐和溴酸盐。水样随着淋洗液进入到离子交换柱系统,分离出水样中的离子(亚硝酸盐、溴酸盐),并应用相关检测其分析其在水样中的含量。检出限约在0.09 μg/L,相对偏差均小于4.30%,回收率在97.20%以上。该方法有较高的准确度,实际应用价值高。离子色谱法作为一项液相色谱技术,充分利用了离子交换的原理,对样品中共存的多种离子进行分离、定性和定量~([1])。不同用途的水中阴离子的含量各异,本次研究就饮用水中亚硝酸盐、溴酸盐两种离子的含量进行测定。人类长期饮用亚硝酸盐含量为5.00 μg/L的饮用水时,患癌概率会大大提高;亚硝酸盐则是判断水体有无受到污染的关键指标。本文就离子色谱法检测水样的实际效果进行探讨,过程如下。     

高压离子色谱法快速测定饮用水中溴酸盐和亚硝酸盐

采用Dionex Integrion高压离子色谱仪和Ionpac AS19高容量分析柱,以自动发生装置在线产生KOH作淋洗液,通过抑制型电导检测器进行饮用水样品中溴酸盐和亚硝酸盐含量的测定。结果表明,目标物溴酸盐和亚硝酸盐在5 min内实现分离,其检出限分别为0.46,0.22μg/L。溴酸盐和亚硝酸盐分别在0～100,0～50μg/L呈良好的线性关系,其加标回收率分别为98.6%～101.3%,100.1%～106.0%,相对标准偏差分别为1.26%～4.12%,1.69%～4.27%。该方法简便快速,灵敏准确、环保高效,适用于饮用水中痕量溴酸盐和亚硝酸盐的测定。     

水中氟离子改性活性炭去除效果研究

采用不同浓度AlCl3对活性炭进行改性处理,通过改性活性炭对水中氟离子的去除效果,确定最佳AlCl3浓度;同时研究了活性炭类型、活性炭用量和吸附时间对水中氟离子去除效果的影响。结果表明,0.50 mol/L AlCl3改性后的活性炭吸附24 h可以使水中氟离子质量浓度由6.41 mg/L降至0.45 mg/L,氟离子去除率最大,因此0.50 mol/L为AlCl3改性最佳浓度。活性炭类型不同,改性后对水中氟离子去除效果不同。随着活性炭用量的增加和吸附时间的延长,水中氟离子去除率增大。氟离子质量浓度为14.14 mg/L的水,经0.8 g改性活性炭吸附9 h后,水中氟离子质量浓度小于1 mg/L。     

液相色谱-串联质谱法测定饮用水中的卤氧化物

目的建立一种液相色谱-串联质谱(liquid chromatography-tandem mass spectrometry,LC-MS/MS)同时检测饮用水中3种卤氧化物(高氯酸盐、氯酸盐及溴酸盐)的分析方法。方法水样直接经0.22μm水系滤膜过滤,采用100 mmol/L乙酸铵(A)和乙腈(B)作为流动相进行等度洗脱,经IC-Pak~(TM) Anion HR色谱柱分离,质谱(ESI-)采用多离子检测模式(MRM)对3种卤氧化物的定量离子和定性离子进行监测。结果本方法在6min内即完成3种目标化合物的分离分析。高氯酸盐及溴酸盐在0.5~50μg/L浓度范围内线性良好、氯酸盐在0.5~100μg/L浓度范围内线性良好(r≥0.999)。添加浓度为0.5、10.0、50.0μg/L,实验结果表明高氯酸盐、氯酸盐及溴酸盐的回收率可达84.8%~101.4%,相对标准偏差均小于10.0%(n=6)。高氯酸盐、氯酸盐及溴酸的检出限分别为0.1、0.2、0.2μg/L。结论该方法快速、准确、灵敏,适合测定饮用水中高氯酸盐、氯酸盐及溴酸盐的同时测定。     

矿泉水中溴酸盐的形成与控制

<正>正常情况下,自然界的矿泉水中溴酸盐的含量几乎为零,但是因其富含矿物离子的原因,溴离子(Br-)却是普遍都含有。在使用臭氧对含有溴化物的矿泉水进行杀菌消毒时,溴化物容易与臭氧发生反应,被氧化成为溴酸盐,并以Br03-的形式存在于水中。由于国家饮用水标准对菌落数量的要求非常严格,不少饮用水厂家采用O3对其水产品开展杀菌消毒的工作以降低菌落数量,由此也就顺理成章     

Reliable identification of grapevine rootstock varieties using RAPD PCR on woody samples

Since grapevine ( Vitis spp .) rootstock material is being traded increasingly as disbudded woody material a lack of distinctive morphological features on such material necessitates an alternative and reliable means of identification. Methods described here were developed for rapid and efficient extraction of DNA from woody samples rich in phenolic compounds and polysaccharides, and for subsequent identification of varieties by RAPD PCR. Using these methods, and with the application of only one selected RAPD primer, we were able to differentiate sixteen rootstock varieties, including the seven varieties most commonly used in Germany. Problems commonly encountered with reproducibility of RAPD patterns were avoided by choosing primers with a dinucleotide sequence and a high G/C content that allowed a rather high annealing temperature of 45°C. Methods described here should also be useful for other horticultural crops, especially those with woody tissues rich in phenolic compounds and polysaccharides.     

Aroma characterization of various apricot varieties using headspace–solid phase microextraction combined with gas chromatography–mass spectrometry and gas chromatography–olfactometry

The characterization of the aromatic profile of several apricot cultivars with molecular tracers in order to obtain objective data concerning the aromatic quality of this fruit was undertaken using headspace–solid phase microextraction (HS–SPME). Six apricot cultivars were selected according to their organoleptic characteristics: Iranien, Orangered, Goldrich, Hargrand, Rouge du Roussillon and A4025. The aromatic intensity of these varieties measured by HS–SPME–Olfactometry were defined and classified according to the presence and the intensity of grassy, fruity and apricot like notes. In the six varieties, 23 common volatile compounds were identified by HS–SPME–GC–MS. Finally, 10 compounds, ethyl acetate, hexyl acetate, limonene, β-cyclocitral, γ-decalactone, 6-methyl-5-hepten-2-one, linalool, β-ionone, menthone and (E)-hexen-2-al were recognized by HS–SPME–GC–O as responsible of the aromatic notes involved in apricot aroma and considered as molecular tracers of apricot aromatic quality which could be utilized to discriminate apricot varieties.     

Tests of potential functional barriers for laminated multilayer food packages. Part I: Low molecular weight permeants

The advent of the functional barrier concept in food packaging has brought with it a requirement for fast tests of permeation through potential barrier materials. In such tests it would be convenient for both foodstuffs and materials below the functional barrier (sub-barrier materials) to be represented by standard simulants. By means of inverse gas chromatography, liquid paraffin spiked with appropriate permeants was considered as a potential simulant of sub-barrier materials based on polypropylene (PP) or similar polyolefins. Experiments were performed to characterize the kinetics of the permeation of low molecular weight model permeants (octene, toluene and isopropanol) from liquid paraffin, through a surrogate potential functional barrier (25 μm-thick oriented PP) into the food simulants olive oil and 3% (w/v) acetic acid. These permeation results were interpreted in terms of three permeation kinetic models regarding the solubility of a particular model permeant in the post-barrier medium (i.e. the food simulant). The results obtained justify the development and evaluation of liquid sub-barrier simulants that would allow flexible yet rigorous testing of new laminated multilayer packaging materials.     

Analysis of benzo[a]pyrene in spiked fatty foods by second derivative synchronous spectrofluorimetry after microwave-assisted treatment of samples

A simple, rapid and inexpensive method has been developed for the determination of benzo[a     

The development of reference materials for paralytic shellfish poisoning toxins in lyophilized mussel. II: Certification study

This paper describes the second part of a project undertaken to develop certified mussel reference materials for paralytic shellfish poisoning toxins. In the first part two interlaboratory studies were undertaken to investigate the performance of the analytical methodology for several PSP toxins, in particular saxitoxin and decarbamoyl-saxitoxin in lyophilized mussels, and to set criteria for the acceptance of results to be applied during the certification exercise. Fifteen laboratories participated in this certification study and were asked to measure saxitoxin and decarbamoyl-saxitoxin in rehydrated lyophilized mussel material and in a saxitoxin-enriched mussel material. The participants were allowed to use a method of their choice but with an extraction procedure to be strictly followed. The study included extra experiments to verify the detection limits for both saxitoxin and decarbamoyl-saxitoxin. Most participants (13 of 15) were able to meet all the criteria set for the certification study. Results for saxitoxin.2HCl yielded a certified mass fraction of <0.07 mg/kg in the rehydrated lyophilized mussels. Results obtained for decarbamoyl-saxitoxin.2HCl yielded a certified mass fraction of 1.59+/-0.20 mg/kg. The results for saxitoxin.2HCl in enriched blank mussel yielded a certified mass fraction of 0.48 +/- 0.06 mg/kg. These certified reference materials for paralytic shellfish poisoning toxins in lyophilized mussel material are the first available for laboratories to test their method for accuracy and performance.     

Announcing a new international peer-reviewed journal:Food Science and Human Wellness now accepting manuscript submission in English

<正>We are pleased to announce the launch of a new international peer-reviewed journal-Food Science and Human Wellness,ISSN 2213-4530,which is an open access journal,produced and hosted by Elsevier B.V.on behalf of Beijing Academy of Food Sciences.Food Science and Human Wellness is an international peer-reviewed English journal that provides a forum for the dissemination of the     

Chinese CTP Market

According to Printing and Printing Equipment Industries Association of China（PEIAC）＇s statistics to the plate manufucturer in China, in 2013, the actual offset plate production has reached 346 million square meters in China. Among them, the CTP production volume was 245 million square meters, up by 11% than that of last year; the total sales of the CTP plate was 239 million square meters, up by 13%.     

Preparatory Work of Print China 2015 is Going Smoothly

正Held at Guangdong Modern International Exhibition Center,Print China 2015 will cover 7exhibition halls,besides the original Hall No.3,4,5,6,7,the newly built F zone of Hall 3 will be used too.The total area will be140,000 square meters.Hall 3:Offset and large printing equipment,package printing equipment,post press     

INFOPRINT 2014 was Successfully Held in Dongguan

Sponsored by Printing and Printing Equipment Industries Association of China （PEIAC） and organized by Print China magazine, the Seventeenth Beijing International Printing Information Conference （INFOPRINT 2014） was successfully held on 11th Dec. 2014 at Dongguan Exhibition International Hotel.