高效液相色谱-串联质谱法测定鲆鲽类水产品中喹诺酮的不确定度评定

采用高效液相色谱-串联质谱法测定鲆鲽类水产品中的氧氟沙星、培氟沙星、诺氟沙星和洛美沙星残留量。参照标准SN/T 1751.2-2007 《进出口动物源食品中喹诺酮类药物残留量检测方法 第2部分:液相色谱-质谱/质谱法》建立了数学模型,分析不确定度的来源并评定。当鲆鲽类水产品中氧氟沙星含量为9.26 μg/kg时,其扩展不确定度为1.04 μg/kg（k=2）;培氟沙星含量为10.08 μg/kg,其扩展不确定度为1.09 μg/kg（k=2）;诺氟沙星含量为9.73 μg/kg时,其扩展不确定度为1.34 μg/kg（k=2）;当洛美沙星含量为9.57 μg/kg,其扩展不确定度为0.99 μg/kg（k=2）。结果表明,不确定度主要来自标准曲线拟合、高效液相色谱-串联质谱仪和标准溶液配制。     

超高效液相色谱-串联质谱法测定猪肉中β-受体激动剂残留量的不确定度分析

采用超高效液相色谱-串联质谱法对猪肉中沙丁胺醇、盐酸克伦特罗和莱克多巴胺含量的不确定度进行评估。根据JJF 1135—2005《化学分析测量不确定度评定》和JJF 1059.1—2012《测量不确定度评定与表示》中的有关规定,建立测定猪肉中3种β-受体激动剂残留量不确定度的数学模型,逐层对不确定度来源进行分析。通过对不确定度分量进行量化和合成,得出当猪肉中沙丁胺醇含量为1.99μg/kg时,其扩展不确定度为0.25μg/kg(k=2);当猪肉中盐酸克伦特罗含量为2.04μg/kg时,其扩展不确定度为0.24μg/kg(k=2);当猪肉中莱克多巴胺含量为1.97μg/kg时,其扩展不确定度为0.24μg/kg(k=2)。评定结果表明,影响检测结果的主要因素为标准溶液配制、标准曲线拟合和测量重复性等。     

气相色谱-串联质谱法测定果汁中毒死蜱残留量的不确定度评定

目的评定气相色谱-串联质谱法测定果汁中毒死蜱残留量的不确定度。方法依据国家计量技术规范JJF 1059.1-2012《测量不确定度评定与表示》对毒死蜱测定中的不确定度来源进行分析,通过建立数学模型量化不确定度分量,计算合成不确定度和扩展不确定度。结果本方法的不确定度主要来源于标准曲线的配制和样品的稀释过程。当果汁中毒死蜱残留量为41.1μg/kg,扩展不确定度为9.8μg/kg,毒死蜱残留量表示为(41.1±9.8)μg/kg(k=2)。结论该评定方法可用于气相色谱-串联质谱法对果汁中毒死蜱残留量的不确定分析。     

同位素稀释-超高效液相色谱-串联质谱法测定水产品中孔雀石绿、结晶紫及其代谢物残留量的不确定度评定

建立同位素稀释-超高效液相色谱-串联质谱法同时测定水产品中孔雀石绿、结晶紫、隐性孔雀石绿、隐性结晶紫残留的不确定度评定方法,依据GB/T 19857-2005《水产品中孔雀石绿和结晶紫残留量的测定》,建立数学模型,通过不确定度来源分析建立不确定度评价方法。结果表明:标准溶液的配制和标准曲线拟合引入的不确定度最大,而同位素稀释法可以减小前处理过程和基质效应引入的不确定度。水产品中孔雀石绿残留量为14.26 μg/kg时,其扩展不确定度为1.35 μg/kg(k=2);结晶紫残留量为15.28 μg/kg时,其扩展不确定度为1.29 μg/kg(k=2);隐性孔雀石绿残留量为14.47 μg/kg时,其扩展不确定度为1.21 μg/kg(k=2);隐性结晶紫残留量为14.69 μg/kg时,其扩展不确定度为1.24 μg/kg(k=2)。     

高效液相色谱法测定牛奶中甲砜霉素残留量的不确定度评定

目的评定高效液相色谱法(high performance liquid chromatography,HPLC)测定牛奶中甲砜霉素残留量的不确定度。方法根据GB29689-2013《食品安全国家标准牛奶中甲砜霉素残留量的测定高效液相色谱法》和JJF1059.1-2012《测量不确定度评定与表示》,建立分析HPLC测定牛奶中甲砜霉素残留量不确定度的数学模型,通过对整个测定过程中的不确定度来源进行分析和合成,运用最小二乘法对甲砜霉素标准曲线拟合的不确定度进行评定。结果当取样量为5.00 g, k=2(95%置信度)时,测得甲砜霉素理论含量为100μg/kg的牛奶中甲砜霉素的残留量为(91.4±2.2)μg/kg。结论本方法的主要不确定来源为标准溶液浓度、标准曲线拟合以及试样测量重复性。     

气相色谱法测定蜂蜜中马拉硫磷残留量的不确定度评定

评定气相色谱法测定蜂蜜中马拉硫磷残留量的不确定度。方法 参照JJF 1059.1-2012《测量不确定度评定与表示》和JJF1135-2005《化学分析测量不确定度评定》, 建立气相色谱法测定蜂蜜中马拉硫磷残留量的不确定度的数学模型, 对测量过程中各测量不确定度分量进行分析和计算。结果 通过对各测量不确定度分量的计算和合成,蜂蜜样品中马拉硫磷的残留量为0.021 mg/kg, 扩展不确定度为0.0037 mg/kg(k=2)。结论 气相色谱法测定蜂蜜中马拉硫磷残留量的不确定度主要来源为标准曲线的拟合, 其次是样品测量重复性和标准溶液, 而回收率与样品前处理影响较小。     

超高效液相色谱-三重四级杆质谱法测定猪肉中氯霉素残留量的不确定度评定

目的采用超高效液相色谱-三重四级杆质谱法(ultra performance liquid chromatography-tandem mass spectrometry,UPLC-MS/MS)测定猪肉中的氯霉素残留量,并进行不确定度评定。方法依据JJF1059.1-2012《测量不确定度评定与表示》,结合数学模型和实验过程,分析测定结果的主要测量不确定度来源,评定各标准不确定度的分量。结果不确定度主要来源于标准溶液配制和标准曲线拟合。当猪肉中氯霉素残留量测定结果为1.07μg/kg时,其扩展不确定度为0.12μg/kg,结果表示为(1.07±0.12)μg/kg (k=2)。结论该评定方法适用于超高效液相色谱-串联质谱法测定猪肉中氯霉素残留量的不确定度分析,可以为科学评价药物残留测量结果的准确性提供依据。     

超高效液相色谱-串联质谱法测定菜籽油中 乙基麦芽酚残留量的不确定度评定

利用超高效液相色谱-串联质谱法测定菜籽油中乙基麦芽酚的残留量,并根据建立的数学模型评定该方法的不确定度的各分量。结果表明,标准曲线拟合和标准溶液配制所产生的不确定度分量最大。当菜籽油中乙基麦芽酚含量为10.096μg/kg时,其扩展不确定度为1.544μg/kg(k=2)。     

高效液相色谱法测定食品中桔青霉素的不确定度分析

采用高效液相色谱法对食品中桔青霉素残留量测定的不确定度进行评估。依据JJF 1135-2005《化学分析测量不确定度评定》和JJF 1059.1-2012《测量不确定度评定与表示》规定的测量不确定度的基本方法,建立数学模型,分析食品中桔青霉素的不确定度来源,通过对不确定度分量进行量化和合成,得出当食品中桔青霉素残留量为154μg/kg时,其扩展不确定度为8.6μg/kg(k=2)。评定结果表明,影响检测结果的主要因素为标准曲线拟合、样品前处理过程和测量重复性等。     

高效液相色谱-串联质谱法测定牛奶中3种磺胺类药物残留不确定度的评定

目的采用高效液相色谱-串联质谱法对牛奶中磺胺吡啶、磺胺噻唑和磺胺甲基异恶唑残留的不确定度进行评估。方法建立测定牛奶中磺胺吡啶、磺胺噻唑和磺胺甲基异恶唑含量不确定度的数学模型,确定不确定度来源并对其评定。结果当牛奶中磺胺吡啶含量为5.09μg/kg时,其扩展不确定度为0.62μg/kg(k=2);当牛奶中磺胺噻唑含量为8.62μg/kg时,其扩展不确定度为0.71μg/kg(k=2);当牛奶中磺胺甲基异恶唑含量为10.15μg/kg时,其扩展不确定度为0.81μg/kg(k=2)。其中,测量重复性和标准曲线对不确定度的影响最大。结论影响检测结果不确定度的主要因素为样品测量的重复性、标准曲线拟合和样品的前处理过程。     

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.