烟用香精香料中3,4,5-三羟基苯甲酸的测定

建立了高效液相色谱测定烟用香精香料中3,4,5-三羟基苯甲酸含量的方法:采用乙醇为萃取剂和稀释剂,样品经振荡提取后,以C18(100 mm×3.9 mm,5μm)为色谱柱,甲醇+0.05%磷酸水溶液(6∶94)为流动相等度洗脱,用二极管阵列检测器测定,检测波长为272 nm.实验结果表明:3,4,5-三羟基苯甲酸在0.1~10.0 mg/L范围内线性相关系数为0.999 4,检出限为1.01μg/g,加标回收率为93.1%~103.2%,RSD5%(n=5).该方法具有灵敏度高、准确性好、操作简易等优点,适用于不同类型烟用香精香料中3,4,5-三羟基苯甲酸的含量测定.     

自动电位滴定法测定烟用香精香料的酸值

为解决采用滴定法测定烟用香精香料酸值时滴定液的配制过程复杂、稳定性不高,以及样品的检测时间长、通量较低等问题,建立了一种测定烟用香精香料酸值的自动电位滴定分析方法。以低、中、高3个梯度酸值的19个烟用香精香料样品为研究对象,采用该方法和行业标准方法进行测定,并对测定结果进行两配对样本T检验。同时,测定了151种烟用香精香料样品。结果表明:①优化确定的条件为:以0.1 mol/L氢氧化钾标准溶液为滴定液,用40 mL 41.7%乙醇溶解样品,样品量为0.8~1.0 g。②方法的相对标准偏差为0.5%~2.3%(n=6),重复性较好。③两种分析方法的测试结果之间不存在显著差异,方法的准确性较好。④151个实际样品检测结果的极差为0.00~0.60,满足行业标准对平行样的测定要求,表明方法的实用性较强。该方法简便、快速、准确,适合于烟草企业大批量、多牌号烟用香精香料酸值的测定。     

离子色谱法测定烟用香精香料中的硝酸根和亚硝酸根

对烟用香精香料中的NO3–和NO2–采用振荡萃取,建立了快速检测烟用香精香料中的NO3–和NO2–的离子色谱法(IC)。香精香料试样中的NO3–和NO2–在振荡条件下用水、二氯甲烷萃取,经0.22 μm滤膜净化,柱流速为1.0 mL/min,采用浓度梯度洗脱方式,IonPac AS11阴离子分析柱、电导检测器检测,并采用该方法测定了15个烟用香精香料样品。结果表明:①NO3–和NO2–的检出限、回收率、相对标准偏差（RSD）及线性范围分别为0.010和0.006 μg/mL,95.4%和90.6%,3.42%和4.61%,0.06 ~ 6.0 μg/mL和 0.02 ~ 2.0 μg/mL;② 测定的15个烟用香精香料样品中NO3–的检出率53.3%,NO2–的检出率40.0%。该方法具有快速、灵敏、简便等优点,适合于烟用香精香料样品中NO3–和NO2–的测定。      

液相色谱-串联质谱法测定烟用香精香料中的氨基酸

建立了测定烟用香精香料中18种氨基酸的液相色谱-串联质谱(LC-MS/MS)方法。以L-正缬氨酸(Nva)为内标,样品经10%甲醇-水溶液(盐酸浓度为0.1 mol/L)萃取、0.22μm水相滤膜过滤后直接进行LC-MS/MS分析。结果表明:18种氨基酸在0.1~10μmol/L范围内,线性相关系数均≥0.9990,3个加标水平的回收率在85.4%~110.0%之间,相对标准偏差(RSD)为1.3%~4.9%。方法的检出限(LOD)和定量限(LOQ)分别为0.00005~0.1和0.0002~0.3μmol/L。该方法准确、灵敏,适合用于烟用香精香料样品中氨基酸的测定。     

烟用香精香料的GC/MS指纹图谱

采用无水乙醇溶解-GC/MS法对8种烟用香精香料不同批次样品、掺兑品和稀释品的主要挥发、半挥发性成分进行分离和鉴定,建立了烟用香精香料的GC/MS指纹图谱,通过色谱图中能代表样品主要挥发、半挥发性成分的色谱峰峰面积,利用夹角余弦法和欧式距离比值法计算不同样品之间的相似度。结果表明:1该方法操作简便、快速,各色谱峰峰面积的相对标准偏差均小于6%,适用于烟用香精香料成分的快速检测;2不同批次样品之间相似度较高,夹角余弦和欧式距离比值都能在一定程度上反映不同样品主要挥发、半挥发性成分的差异,而欧式距离比值更能反映样品之间浓度的变化。     

固相萃取-液质联用法测定乳制品中对羟基苯甲酸酯

建立了乳制品中的对羟基苯甲酸酯类防腐剂对羟基苯甲酸甲酯(MP)、对羟基苯甲酸乙酯(EP)、对羟基苯甲酸丙酯(PP)和对羟基苯甲酸正丁酯(BP)的高效液相色谱(HPLC)初筛、质谱(MS)确认的分析方法.样品用甲醇溶解后,用固相萃取柱(SPE-C18)进行净化.使用C18反相色谱柱分离,以甲醇溶液-水溶液为流动相,采用梯度洗脱.二极管阵列检测器检测,检测波长254nm,4种防腐剂在12min之内完全分离.在选定的条件下各组分的相关系数均大于0.9994,线形范围0.01～100mg/L,回收率为97.4%～106%.并用负离子一级质谱进行进一步确认分析.本方法用于乳制品中的对羟基苯甲酸酯类防腐剂的测定,具有快速、简便、准确的特点.     

液相色谱串联质谱法测定烟用纸张中的芳香胺

建立了液相色谱串联三重四级杆质谱(LC-MS/MS)测定烟用纸张中20种芳香胺的检测方法。用柠檬酸缓冲液浸泡烟用纸张,加入连二亚硫酸钠还原为芳香胺,浸泡液过固相萃取小柱后,用甲醇洗脱,并浓缩定容,进行液相色谱串联质谱测定。该方法的回收率为77.5%～112.1%, 精密度(RSD)为1.4%～13.4%,检出限均小于0.1 ng/mL。该方法灵敏度高,分析时间短,适用于烟用纸张中芳香胺的测定。     

液相色谱串联质谱法测定烟用香精香料中的亚硝胺

建立了液相色谱串联质谱法(LC-MS/MS)测定烟用香精及料液中N-亚硝基去甲基烟碱(NNN)、N-亚硝基假木贼碱(NAB)、N-亚硝基新烟草碱(NAT)和4-(N-甲基-N-亚硝胺)-1-(3-吡啶基)-丁酮(NNK)4种烟草特有亚硝胺(TSNAs)的方法。样品采用含0.1 mol/L的醋酸铵甲醇水溶液溶解提取,在C18色谱柱上采用梯度洗脱分离目标物和干扰物,电喷雾正离子模式下,多反应检测模式测定。结果表明,4种TSNAs的检测限(S/N=3)和定量限(S/N=10)分别为0.4~1.6 ng/g和1.4~4.8 ng/g,标准工作液在1~50 ng/L的范围内线性良好,相关系数均大于0.9995,高中低三个浓度水平的加标回收率在93.5%~105.9%之间,6次重复实验的RSD范围为1.8%~4.7%,均小于5%。使用该方法分析测定了8个市售烟用香精香料样品,其中3个样品检测到TSNAs。该方法准确、灵敏,适用于烟用香精及料液样品中TSNAs的分析检测。     

液相色谱串联质谱法测定烟用香精香料中的亚硝胺

建立了液相色谱串联质谱法(LC-MS/MS)测定烟用香精及料液中N-亚硝基去甲基烟碱(NNN)、N-亚硝基假木贼碱(NAB)、N-亚硝基新烟草碱(NAT)和4-(N-甲基-N-亚硝胺)-1-(3-吡啶基)-丁酮(NNK)4种烟草特有亚硝胺(TSNAs)的方法。样品采用含0.1 mol/L的醋酸铵甲醇水溶液溶解提取,在C18色谱柱上采用梯度洗脱分离目标物和干扰物,电喷雾正离子模式下,多反应检测模式测定。结果表明,4种TSNAs的检测限(S/N=3)和定量限(S/N=10)分别为0.4~1.6 ng/g和1.4~4.8 ng/g,标准工作液在1~50 ng/L的范围内线性良好,相关系数均大于0.9995,高中低三个浓度水平的加标回收率在93.5%~105.9%之间,6次重复实验的RSD范围为1.8%~4.7%,均小于5%。使用该方法分析测定了8个市售烟用香精香料样品,其中3个样品检测到TSNAs。该方法准确、灵敏,适用于烟用香精及料液样品中TSNAs的分析检测。     

气相色谱质谱联用仪测定食用酒精中的甲醇含量

探索了一种用气相色谱质谱联用仪测定食用酒精中的甲醇含量的方法,食用酒精样品经脱水处理,在气相色谱中用Rtx?-Wax毛细管色谱柱分离,在质谱中采用全扫描方法和选择离子扫描方法分析检测。研究结果表明,该方法精密度高并且回收率好。相对于气相色谱法,用气相色谱质谱联用仪测定食用酒精中的甲醇含量,定性更方便,定量更准确。     

Review of techniques to manufacture micro-hydrogel particles for the food industry and their applications

Microgels are ‘soft’ microscopic cross-linked polymeric particles that are being increasingly exploited in a variety of industries for rheology control, encapsulation and targeted delivery. They are valued because of the ability to tune their functionality to address specific applications in oil recovery, coatings, drug delivery, cosmetics, personal care and foods. Food microgels are typically biopolymer hydrogels in the form of microspheres, nanospheres (also called nanogels), spheroids and fibres. The utilisation of engineered microgels in foods has so far been limited, despite their great potential to address several needs in the food industry, including: satiety control, encapsulation of phytonutrients and prebiotics, texture control for healthier food formulations (e.g. reduced fat products), and targeting delivery to specific areas in the digestive tract. We review the scientific and patent literature on the utilisation and manufacturing methods for producing microgels with an emphasis on micro-hydrogels for food applications.     

12—A CRITIQUE OF SOME HYPOTHESES RELATING TO THE HETEROGENEITY OF THE HIGH-SULPHUR PROTEINS OF WOOL

Joubert and Burns prepared a large number of fractions from the high-sulphur proteins of wool and estimated their molecular weights and amino-acid compositions. Their data have been re-examined in order to look for statistically significant interrelations between amino acids and between the proportion of various amino acids and molecular weight. Statistical analysis of the data is also used to examine the credibility of some hypotheses concerning the mechanism of keratin biosynthesis and to provide further evidence for the existence of families of proteins within the high-sulphur fractions of wool.     

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 Latest Data about Development of Chinese Printing Industry in 2013

In the 2014 China（Shanghai）International Printing Week,Director Wang Yanbin released the latest data about development of Chinese printing industry in 2013.According to statistics,in 2013,the total output value of Chinese printing industry exceeded 1trillion Yuan for the first time,reaching 1.03985 trillion Yuan.There were 105,000 printing enterprises in China,employees were 3.415 million.The total asset was 1.06247 trillion Yuan;     

The State Council Issued "Directory of Government Approved Investment Projects(2013 Edition)"

正On December 2nd,2013,the State Council issued the notification of"Directory of Government Approved Investment Projects(2013 Edition)"(hereafter referred to as"notification").It is pointed out in the"notification"that in order to further deepen reforms in investment systems and administrative examination and approval systems,simplify administrative procedures and delegate powers to lower levels,earnestly     

China textile machinery: taking off in progress

正Among the 1600 exhibitors who take apart in the ITMA ASIA+CITME2014 2/3 are Chinese manufactures.If the numerous figures failed to attract your attention,the increase of quality should draw your focus.To adopt the demand of developing textile machine market,domestic textile machinery enterprises now follow the slogan of"technology drives development"to enhance product competitiveness.Our domestic sellers will showcase product ranging from spinning,weaving,dyeing and printing,     

Top Ten News of China's Paper Industry 2013

On December 24th, 2013, the meeting on the selection of top 10 news of China＇s paper industry 2013 sponsored by 〈China Paper Newsletters〉 was held in Beijing. The yearly selection of the top l0 news, which began in 2000, has become a brand activity widely recognized in the industry thanks to the support from the authorities at all levels and public participation.     

National Development and Reform Commission Issued Announcement for Selection of Major Preliminary Research Projects for the "13~(th) Five-Year Plan"

In Apri Commi major p Plan＂ （h 2014, the National Development and Reform ssion issued an announcement for selection of reliminary research projects for the ＂13th Five-Year ereafter referred to as ＂The Announcement＂）     

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 latest scientific     

Contamination of animal feed and food from animal origin with mineral oil hydrocarbons

Oils and fats used for the production of animal feed can become contaminated with mineral oil material originating from gas oils (C₁₈-C₃₅) or synthetic oils (poly alpha olefins, C₂₅ to beyond C₄₅). An important cause is assumed to be the discharge of waste oils, such as motor oil and hydraulic oils. Mineral oil material was analysed by on-line LC-GC-FID directly in the fat or in a raw extract from animal feed or foodstuffs. In Switzerland in summer/autumn 1999 concentrations in oils and fats for feed production were often found to be between 100 and 1000mg/kg. In the feeds, the average concentration was around 100mg/kg with values ranging up to a maximum of 1000mg/kg; few samples were free of contamination. In animal body fat, the average concentration determined in summer 1999 was 25mg/kg, with a maximum of 150mg/kg, although in samples from December 1999, contamination was substantially lower. In the fat phase of eggs, the average concentration was 30mg/kg, with a maximum of 80mg/kg. Paraffin oil is used for feed production, which may account for part of the contamination problem (e.g. eggs).