7种葡萄糖四酯主要裂解产物在卷烟主流烟气中的转移分布

对C3~C6脂肪酸的7种葡萄糖四酯在红塔集团某牌号卷烟主流烟气中的裂解转移分布规律进行了研究。通过收集主流烟气粒相物和气相物,对粒相物和气相物进行GC/MS定性定量分析,测定了7种葡萄糖四酯主要裂解产物在主流烟气粒相物和气相物中的转移率。结果表明:①所建立的方法测定脂肪酸组分的回收率为86.27%~98.80%,RSD低于2.63%,线性相关系数大于0.999。②7种葡萄糖四酯裂解相应的脂肪酸向主流烟气粒相物和气相物中的转移率分别为0.34%~12.85%和0.004%~0.73%,总转移率为1.07%~12.86%。③主流烟气粒相中转移率随碳原子个数的增加而增加,气相随碳原子个数增加而逐渐减少;粒相转移率普遍要高于气相。④相同分子量的葡萄糖四酯,异构体比正构体的转移率高。     

一些脂肪酸类香料单体在卷烟中的转移

采用同时蒸馏萃取和气相色谱、气相色谱/质谱法测定了C5～C1410种脂肪酸类香料单体在卷烟中的分布及其向主流烟气粒相物和滤嘴中的转移率.结果表明:①10种脂肪酸的烟丝持留率为30.34%～56.67%,散失率42.34%～68.15%,滤嘴迁移率0.17%～1.50%;②10种脂肪酸向主流烟气粒相物中的转移率为0～17.26%,滤嘴截留率2.85%～13.87%;③戊酸至十四酸等8种同系酸向主流烟气中的转移率随着其分子量的增大而增大,但其烟丝持留率、散失率、滤嘴截留率和滤嘴迁移率变化的规律性较差;④戊酸和异戊酸、3-甲基戊酸和己酸,均是异构酸的烟丝持留率较正构的低,其散失率、主流烟气转移率、滤嘴迁移率和滤嘴截留率则较正构的高.     

UPLC-MS/MS测定卷烟烟气、滤嘴和烟灰中5种常用杀菌剂及其转移行为研究

建立了UPLC-MS/MS测定主流烟气总粒相物、气相物、滤嘴、烟蒂烟丝和烟灰中霜霉威、多菌灵、稻瘟灵、三唑醇和三唑酮含量的方法,样品经乙腈或甲醇提取,分散固相萃取后,进行UPLC-MS/MS分析。5种杀菌剂在各基质中的检出限为0.325~1.832ng/cig,平均回收率为90.9%~111.8%,RSD为1.3%~10.1%。应用该方法研究了标准卷烟加标样品和自然高残留样品中杀菌剂的烟气转移率,结果表明:标准卷烟加标样品中,5种杀菌剂向主流烟气总粒相物、滤嘴中的平均转移率分别为29.4%和11.0%,向烟蒂烟丝和烟灰中平均转移率为1.6%和0.2%,主流烟气气相物中则未检出杀菌剂;主流烟气总粒相物中,多菌灵的转移率较低（<5%）,其它4种杀菌剂则接近或超过30%。自然高残留卷烟样品中,5种杀菌剂向烟气总粒相物中平均转移率为3.7%,在滤嘴中平均转移率为2.2%。卷烟实际燃吸过程中5种杀菌剂向烟气总粒相物转移率明显低于加标研究结果;若采用加标研究结果,成品卷烟杀菌剂残留对吸烟者的健康风险将被高估。      

两种加香方式下7种葡萄糖苷配基在烟气中的裂解转移规律

目的:研究7种葡萄糖苷添加到卷烟纸上裂解产生的糖苷配基在主流和侧流烟气中的转移规律。方法:将5-甲基糠醇葡萄糖苷、薄荷醇葡萄糖苷、大茴香醇葡萄糖苷、叶醇葡萄糖苷、苯乙醇葡萄糖苷、乙基香兰素葡萄糖苷和香兰素葡萄糖苷7种单体香料按烟丝重量的0.01%分别涂抹到卷烟纸表面和注射到卷烟中,测定两种加香方式下其裂解的糖苷配基在主流烟气和侧流烟气中的裂解转移率,在此基础上分别以0.001%,0.010%,0.050%的添加量涂抹到卷烟纸上,测定7种糖苷配基在主、侧流烟气中的转移率。结果:烟丝加香方式下7种糖苷配基在主流烟气中的转移率高于卷烟纸加香方式,而侧流烟气中的转移率与之相反;糖苷配基在主流烟气和侧流烟气中转移率最高的为5-甲基糠醇,最低的为薄荷醇,其他依次为叶醇、大茴香醇、苯乙醇、乙基香兰素和香兰素;0.001%添加量条件下,7种糖苷配基在主流、侧流烟气中的转移率分别为0.27%~1.24%,0.42%~1.71%,0.010%添加量下分别为0.38%~1.87%,0.54%~2.52%,0.050%添加量下分别为0.31%~1.56%,0.47%~2.19%。结论:3个添加量下,7种糖苷配基在侧流烟气中的转移率均高于主流烟气中的;糖苷配基在主流和侧流烟气中均表现出随添加量的增加先增加后降低的趋势。     

一些醇类香料单体在卷烟中的转移研究

采用同时蒸馏萃取和GC、GC/MS,对注射加入卷烟中的15种醇类香料单体在烟丝中的持留率和滤嘴迁移率,以及抽吸后单体向主、侧流烟气粒相和滤嘴中的转移行为进行了研究.结果表明:醇类同系物香料,小分子量低沸点的单体,其烟丝持留率和主流烟气粒相转移率相对较低,散失率相对较高,而大分子量高沸点的单体,其滤嘴迁移率和滤嘴截留率相对较低;醇类同分异构体香料单体的转移情况不完伞相似;4种醇类香料单体的侧流烟气粒相转移率高于其主流烟气粒相转移率,11种醇类香料单体的侧流烟气粒相转移率低于其主流烟气粒相转移率.     

高效液相色谱法测定卷烟燃烧生成的羰基化合物的分布

选择2,4-二硝基苯肼作为衍生化试剂,采用高效液相色谱(HPLC)法研究了7个卷烟燃烧后生成的8种羰基化合物的含量及在主流烟气、侧流烟气气相物、侧流烟气粒相物和滤嘴中的分布情况。结果表明:18种羰基化合物的总量为3 971.6~5 375.4μg/支,含量分布规律为侧流气相主流烟气侧流粒相滤嘴,主流烟气中羰基化合物以乙醛含量最高,丙酮次之;2随着焦油量的变化,主流烟气中羰基化合物的含量差别较大,而羰基化合物总量的差异不明显;一定程度上,主流烟气和滤嘴中的羰基化合物含量分别与焦油量成正比;3通过测定滤嘴中羰基化合物的含量,表明对于巴豆醛和甲醛的截留率相对较高,对于乙醛、丙酮和丙醛的截留率相对较低;滤嘴对于卷烟中的低级羰基类化合物的过滤效果并不明显。     

杂环类单体香料在电加热卷烟中的转移行为

为研究杂环类香料在电加热卷烟中的转移行为,利用GC检测并分析了电加热卷烟抽吸前后8种杂环类香料在烟芯、降温段、滤棒和主流烟气粒相物中的分布。结果表明:①8种杂环类单体香料的烟芯持留率为8.68%~69.30%,空气散失率为24.96%~71.50%,烟芯残留率为5.21%~27.13%,滤棒截留率为8.27%~22.72%,烟气转移率为6.16%~28.49%,逐口转移率随抽吸口数序号的增加呈现先增大后减小的趋势;②2-乙酰基吡嗪、2-乙酰基吡啶向烟气的转移率＞25%;③香料的沸点、烟芯持留率、烟芯残留率、滤棒截留率和烟气转移率两两之间存在极显著正相关关系;④互为同系物以及不同环结构的杂环类香料,随着侧链数量依次增多、结构稳定性增强,其烟芯持留率、主流烟气粒相物转移率和逐口转移率逐渐增大,迁移率和空气散失率逐渐减小。      

爆珠中柠檬烯、薄荷醇在卷烟中的转移行为

为研究爆珠中柠檬烯、薄荷醇在卷烟中的转移行为,设计并制备了爆珠不同大小、不同放置位置的常规及细支卷烟样品,采用乙醇浸提、GC-MS法分析了柠檬烯、薄荷醇的转移行为。结果表明:①随爆珠直径的增大,柠檬烯、薄荷醇向主流烟气粒相物的转移率呈增加趋势,而在滤嘴中的截留率呈降低趋势;②随爆珠距滤嘴唇端的距离增大,柠檬烯、薄荷醇向主流烟气粒相物的转移率呈降低趋势,而在滤嘴中截留率总体呈增加趋势;③柠檬烯、薄荷醇向细支烟主流烟气粒相物的转移率高于常规卷烟,而在滤嘴中的截留率低于常规卷烟;④相关性分析表明,爆珠直径与柠檬烯、薄荷醇向主流烟气粒相物的转移率正相关,与柠檬烯、薄荷醇在滤嘴截留率负相关,且均达到极显著水平;爆珠位置与柠檬烯、薄荷醇向主流烟气粒相物的转移率显著负相关,与柠檬烯、薄荷醇在滤嘴中的截留率显著正相关。     

非挥发性有机酸与卷烟主流烟气总粒相物pH关系研究

以国内具有代表性的卷烟为研究对象,分别对卷烟样品的非挥发性有机酸含量和卷烟主流烟气粒相物pH进行了测定,通过数学分析研究了非挥发性有机酸含量对烟气粒相物pH的影响.主流烟气粒相物pH值评价指标与有机酸的关联分析结果表明,苹果酸、十五酸、油酸对主流烟气粒相物pH值相对影响较大.对影响主流烟气粒相物pH值的11种非挥发性有机酸的主成分分析结果表明,亚油酸,油酸,苹果酸,棕榈酸,草酸和亚麻酸对主流烟气粒相物pH值相对影响较大.综上可得,苹果酸和油酸对主流烟气粒相物pH值具有较大影响.     

卷烟主流烟气烟熏香成分的感官导向分析

以感官导向分析方法研究了卷烟主流烟气总粒相物中的烟熏香成分。利用凝胶渗透色谱(GPC)分离卷烟主流烟气粒相物,评价了各分离流份的香气特征,并定位烟熏香特征流份;通过GC/MS法定性分析结合标准物质香气特征评价,鉴定出26种烟熏香成分;建立了主流烟气粒相物中26种烟熏香成分的GC/MS定量分析方法,测定了其在9个品牌卷烟主流烟气中的释放量及在烟气粒相物中的质量分数;利用三点选配法(3-AFC)测定了26种烟熏香成分在乙醇和三乙酸甘油酯中的嗅觉阈值,结合其在卷烟烟气粒相物中的质量分数,计算了9个品牌卷烟烟气粒相物中各烟熏香成分的香气活性值(OAV),推测了26种烟熏香成分的贡献度。结果表明:1在所考察卷烟的主流烟气中,释放量较大的烟熏香成分均为苯酚、对甲酚、4-乙烯基愈创木酚、邻甲酚、2,4-二甲基苯酚和2-(4-羟基苯基)乙醇。2愈创木酚、对甲酚和5-甲基愈创木酚对卷烟烟熏香韵的贡献最大。     

卷烟主流烟气总粒相物中挥发性和半挥发性有机酸的分析

采用二氯甲烷萃取、N,O-双(三甲基硅基)三氟乙酰胺硅烷化、反-2-己烯酸和肉桂酸作内标,接预分离柱和选择离子检测GC/MS法同时测定了卷烟主流烟气中的甲酸、乙酸和二十酸等30种有机酸。方法的回收率为74.3%～101.8%,RSD均小于10%。并采用该法测定了10个牌号国产烤烟型卷烟烟气中有机酸含量。该法适于批量卷烟主流烟气总粒相物中挥发性和半挥发性有机酸的快速分析。     

芳基烷醇-β-D-葡萄糖苷的化学合成与应用

采用改进的Helferich法立体选择合成了芳基烷醇-β-D-葡萄糖苷,合成路线比传统的Koenigs-Knorr法减少了一步,产物收率分别为53%(3a)和49%(3b),通过LC/MS、~1H-NMR、~(13)C-NMR等检测条件对产物结构进行了表征;添加芳基烷醇-β-D-葡萄糖苷对低焦油卷烟的香味具有一定的补偿作用,但转化率很低,仅为7.3%(3a)和5.03%(3b);芳基烷醇-β-D-葡萄耱苷对植物病原菌具有明显的抑制作用。     

深度抽吸模式下6种常用农药在加热卷烟烟气中的转移率

为研究农药在加热卷烟抽吸过程中的转移行为,向不含农药的加热卷烟烟支中添加6种常用农药的混合标准溶液,按照加拿大深度抽吸模式进行卷烟抽吸,捕集主流烟气.采用基质分散固相萃取净化、气相色谱-串联质谱法测定卷烟加热抽吸后各种农药的烟气转移率、滤嘴截留率和烟芯残留量.结果表明:①6种农药在各种基质中的加标回收率在75.5％～1...     

Lc/Esi/Ms/Ms determination of postharvest fungicide residues in citrus juices

An LC-ESI-MS/MS method was developed for the quantitative detection of postharvest fungicide residues in citrus juices and reported in this paper. The analyses of thiabendazole (TBZ), carbendazim (MBC), thiophanate methyl (TPM), imazalil (IMZ) and prochloraz (PCZ) residues were performed by using a gradient elution in conjunction with positive ionization mode electrospray ionization tandem mass spectrometry. Fungicides were extracted from citrus juices with recoveries ranging from 79.8 to 101.2% and relative standard deviation better than 15%. The quantification limits ranged from 0.01 μg/kg IMZ to 0.06 μg/kg for MBC. The LC-MS-MS method was applied to commercial citrus juices, detecting MBC, TBZ and IMZ residues in the 90% of the samples. Prochloraz residues were detected only in one of the multifruit juice (orange, lemon and carrot) samples.     

振荡萃取-GC/MS法测定卷烟主流烟气总粒相物中的14种挥发性有机酸

建立了同时测定卷烟主流烟气总粒相物中甲酸、乙酸和癸酸等14种挥发性有机酸的振荡萃取-气相色谱-质谱联用(GC/MS)方法。捕集了卷烟主流烟气总粒相物的剑桥滤片经添加乙酸苯乙酯内标后,用甲醇振荡萃取,在选择离子监测模式下进行GC/MS分析。结果表明:方法的检出限(LOD)和定量限(LOQ)分别为0.08~3.00和0.26~10.00μg/支,加标回收率为97.5%~110.8%,相对标准偏差为1.2%~8.5%。该方法适用于卷烟主流烟气总粒相物中甲酸、乙酸和癸酸等14种挥发性有机酸的测定。      

Prevalence of Salmonella enterica and Listeria monocytogenes contamination in foods of animal origin in Italy

The present survey collected and analyzed the results of routine testing for Salmonella enterica and Listeria monocytogenes on foods of animal origin submitted for official controls in Italy during 2001 to 2002. Salmonella was detected in 2.2% of 71,643 food samples examined, and the isolation rates ranged from 9.9% for raw poultry meat to less than 0.1% for dairy products. Isolation rates were also high in raw pork (4.9%) and processed meats (5.3%), which often involved pork. Low rates were observed in seafood (0.5%) and in ready-to-eat foods, such as grocery products (0.7%) and ice creams (0.1%). Serotyping showed that approximately 50% of the isolates belonged to the serotypes most commonly isolated from humans in Italy, thus confirming that most cases of human salmonellosis have a foodborne origin. Levels of L. monocytogenes were higher than what is accepted by the current regulation in 2.4% of 42,300 food samples. The positivity rates ranged from 10.3% in raw pork to none in eggs and egg products. Contamination rates were higher in other meat products (between 2 and 5%) and fish (6.5%) than in cheeses (1.1%) and other dairy products (0.6%). Routine control activities on the microbial contamination of foods can generate data with statistical and epidemiological value. Such data can be used as a basis for estimating the exposure of consumers to foodborne pathogens, following the trends of contamination over time, and evaluating the effects of control measures on the contamination of food.     

Quantification of Almond Skin Polyphenols by Liquid Chromatography-Mass Spectrometry

ABSTRACT:  Reverse phase HPLC coupled to negative mode electrospray ionization (ESI) mass spectrometry (MS) was used to quantify 16 flavonoids and 2 phenolic acids from almond skin extracts. Calibration curves of standard compounds were run daily and daidzein was used as an internal standard. The inter-day relative standard deviation (RSD) of standard curve slopes ranged from 13% to 25% of the mean. On column (OC) limits of detection (LOD) for polyphenols ranged from 0.013 to 1.4 pmol, and flavonoid glycosides had a 7-fold greater sensitivity than aglycones. Limits of quantification were 0.043 to 2.7 pmol OC, with a mean of 0.58 pmol flavonoid OC. Mean inter-day RSD of polyphenols in almond skin extract was 6.8% with a range of 4% to 11%, and intra-day RSD was 2.4%. Liquid nitrogen (LN₂) or hot water (HW) blanching was used to facilitate removal of the almond skins prior to extraction using assisted solvent extraction (ASE) or steeping with acidified aqueous methanol. Recovery of polyphenols was greatest in HW blanched almond extracts with a mean value of 2.1 mg/g skin. ASE and steeping extracted equivalent polyphenols, although ASE of LN₂ blanched skins yielded 52% more aglycones and 23% less flavonoid glycosides. However, the extraction methods did not alter flavonoid profile of HW blanched almond skins. The recovery of polyphenolic components that were spiked into almond skins before the steeping extraction was 97% on a mass basis. This LC-MS method presents a reliable means of quantifying almond polyphenols.     

三峡库区调味油脂产品中邻苯二甲酸酯类塑化剂的含量测定和分析

目的采用气相色谱-三重四极杆串联质谱法(gas chromatography-triple quadrupole tandem mass spectrometry,GC-MS/MS)测定三峡库区调味油脂产品中的邻苯二甲酸二正丁酯(dibutyl phthalate,DBP)、邻苯二甲酸二(2-乙基)己酯[bis(2-ethylhexyl)phthalate,DEHP]2种塑化剂的含量,并对污染情况进行分析。方法样品采用乙腈提取,固相萃取(solid-phase extraction,SPE)玻璃小柱净化,氮吹近干后正己烷复溶,经气相色谱-三重四极杆串联质谱法测定。结果DBP、DEHP在一定浓度范围内线性关系良好,相关系数均大于0.998,检出限分别为0.05、0.10 mg/kg,定量限分别为0.17、0.33 mg/kg,平均加标回收率为82.79%~96.70%,相对标准偏差为0.59%~1.76%。在采集的32组调味油脂样品中,DBP的检出率高达68.75%,含量范围在0.15~517.00 mg/kg;DEHP检出率为28.12%,含量范围在0.57~125.00 mg/kg,超标率分别为62.50%和-18.75%。结论三峡库区调味油脂产品中存在一定程度的邻苯二甲酸酯类物质污染,可能与生产、环境等方面的迁移污染相关,需引起重视并进行连续监测。