三甲基戊基环戊酮的定性分析

为得到高产率优质果香的三甲基戊基环戊酮香料单体，配合三甲基戊基环戊酮的合成工作，利用元素分析、NMR、GCMS、IR对合成的三甲基成基环戊酮香料单体进行了定性分析。合成分离出的主产物分子离子峰196，C、H、O实验值分别为79．87、12．62、7.51，经1HNMR分析具有24个H，红外吸收与目的化合物一致，经综合分析，确认主产物是目的化合物三甲基戊基环戊酮香料单体。     

δ-环戊基-δ-内酯的定性分析

利用元素分析 ,1 HNMR,1 3CNMR,GCMS,IR,对由尼龙酸副产物 2亚环戊基环戊酮合成的内酯化产物进行了定性分析 ,确认内酯化产物为 δ 环戊基 δ 内酯香料单体     

δ-环戊基-δ-内酯的合成

采用己二酸副产物环戊酮为原料 ,经醇醛缩合反应得 2 亚环戊基环戊酮 ,经Pd/C催化加氢得 2 环戊基环戊酮 ,再经拜尔 维利格 (Becyer Villiger)氧化反应得δ 环戊基 δ 内酯 ,产品纯度大于 99.5 % (GC法 ) ,总收率大于 81% ,具有清新坚果气息 ,经IR ,GC MS ,1HNMR ,13 CNMR检测结构正确。     

δ-癸内酯的合成

以环戊酮和正戊醛为起始原料,经羟醛缩合、选择性催化加氢、氧化重排制得δ-癸内酯。通过正交实验,得出最佳工艺条件:w(NaOH)=1%,PEG-600用量0.7g,草酸用量0.2g,n(双氧水)∶n(2-戊基环戊酮)=4∶1,甲醇用量30mL,硫酸用量2mL,反应收率为61.2%。采用红外光谱对产物结构进行了表征。     

2-氯-6,7-二氢-5H-环戊并[b]吡啶的合成

实验以环戊酮与苄胺为起始原料,经亲核加成、乙酰化、Vilsmeier反应关环合成了第四代抗生素头孢匹罗的重要中间体2-氯-6,7-二氢-5 H-环戊并[b]吡啶,经3步反应制备了2-氯-6,7-二氢-5 H-环戊并[b]吡啶。合成中间产物N-亚环戊基苄胺的较佳条件为:反应温度为117～121℃,n(苄胺)∶n(环戊酮)=1∶1.02,回流反应时间为40min;合成中间产物N-环戊烯基-N-苄基乙酰胺的较佳条件为:加料温度0～5℃,反应温度25℃,n(苄胺)∶n(乙酸酐)=1∶1.1,反应时间14h;合成2-氯-6,7-二氢-5 H-环戊并[b]吡啶的条件为:三氯氧磷加料温度0～5℃,回流反应时间15h,水解温度为40～45℃。三步反应的总收率为45.9%,产品结构经1 H NMR和LC-MS确证。     

环戊醇液相脱氢本征动力学

以Raney镍为催化剂,对环戊醇脱氢制环戊酮的本征动力学进行了研究。首先通过热力学分析消除了环戊酮加氢逆反应的可能性,并通过机理讨论,认为可以用指数形式来表达环戊醇脱氢速率。采用高斯-牛顿法,根据实验数据进行参数估算,得到了本征动力学模型参数,经统计检验表明,所得动力学模型是适当的。该反应的速率方程为-dcA/dt=kc2A,反应活化能为63 05kJ/mol,反应速率常数为3 1×104exp(-63050/RT)。在动力学研究的基础上,对脱氢微观机理进行了讨论。     

聚丙烯催化剂内给电子体环戊基-1,1-二甲醇二甲醚的合成

以丙二酸二乙酯和1,4-二溴丁烷为起始原料,经烷基化、酯还原和醚化反应合成环戊基-1,1-二甲醇二甲醚,分别考察关键因素对3步合成反应的影响。适宜的工艺条件为：①烷基化反应时,n(丙二酸二乙酯):n(CsOH):n(1,4-二溴丁烷)=1.0:2.2:1.4,CsOH 为催化剂,环戊基-1,1-二甲酸二乙酯的收率为93.0%;②酯还原反应时,以无水ZnCl2为催化剂,n(环戊基-1,1-二甲酸二乙酯):n(KBH4)=2.0:1.0,环戊基-1,1-二甲醇的收率为88.1%;③醚化反应时,以四丁基溴化铵为催化剂,n(环戊基-1,1-二甲醇):n(NaOH):n(碳酸二甲酯)= 1.0:8.0:2.4,环戊基-1,1-二甲醇二甲醚的收率为61.2%。以丙二酸二乙酯为计三步反应的总收率为50.1%。     

6，10，16，19-四氧杂三螺[4．2．2．4．2．2]十九烷的合成

以环戊酮与季戊四醇为原料,用自制纳米二氧化钛负载杂多酸作催化剂,合成了双缩酮化合物6,10,16,19-四氧杂三螺[4．2．2．4．2．2]十九烷。考察了催化剂用量、反应物摩尔比、反应时间等对反应的影响。利用核磁共振光谱对产物进行了表征,最佳条件下标题化合物的收率可达88．5％。     

EDTA络合滴定法定量测定油田水中SO42-的一项改进

测量油气田水中SO4^2-的EDTA络合滴定法在2000年及以后的石油天然气行业标准（SY／T5523（（油气田水分析方法》）中已废止。本工作发现稀释受测水样所用蒸馏水要消耗EDTA，导致测量误差。基于1992年版行业标准，提出了增加蒸馏水校正项的EDTA络合滴定法。将此改进方法用于含各种不同共存离子的自配盐水样中SO4^2-的测量，结果如下：不含SO4^2-的水样SO4^2-测量值均为零；测量结果不受共存离子种类和种数的影响；测量值的相对误差随SO4^2-质量浓度P的增大而减小，P〉1000mg／L时为0、4％～1．0％，P在227．30～755．50mg／L范围时为-5．8％～＋5、8％。均与ICP法十分接近；P在34、97-78、05mg／L范围时测量值相对误差为-8.9％～-13．1％；P低于30mg／L时测量误差很大，此法不适用。重量法用于盐水样中SO4^2-测量时误差很大或测不出。此法用于梁南地层水中SO4^2-的测量，测量值相对于ICP法测量值（340．40～1082．36mg／L）的误差为-2．2％～＋5．1％。表3参4。     

环己烯合成方法研究

介绍3种环己烯合成方法。包括用固体酸作催化剂，环己醇催化脱水制备环己烯，如以SO4^2-／TiO2-SiO2为固体酸催化剂，在反应温度170℃、反应时间1h条件下，环己烯收率达90％；苯在钌系及Ni／海泡石催化剂作用下，选择加氢制备环己烯，在反应温度140℃、压力4。5MPa条件下，苯的转化率为40％，环己烯选择性达85．3％；还有环己烷氧化脱氢制备环己烯，以三氯化铈／浮石为催化剂，空气作氧化剂，在反应温度440～450℃条件下氧化脱氢，环己烷转化率为13．5％，而环己烯收率可达91％。并指出了这3种环己烯合成方法存在的问题和研究方向。     

Further data on the occurrence of Fusarium emerging mycotoxins enniatins (A,A1, B,B1), fusaproliferin and beauvericin in raw cereals commercialized in Morocco

In this study, 64 samples of raw cereals (wheat, maize and barley) purchased from local markets in Rabat–Salé area from Morocco were analyzed for the occurrence of six emerging mycotoxins: four enniatins ENs (ENA, ENA1, ENB and ENB1), beauvericin (BEA) and fusaproliferin (FUS). Samples were extracted with a mixture of water/acetonitrile (85/15, v/v) by using an Ultra-turrax homogenizer. Mycotoxins were then identified and quantified with a liquid chromatography (LC) with diode array detector (DAD). Positive samples were confirmed with an LC–MS/MS. Analytical results showed that the frequencies of contamination of total samples with ENs, BEA and FUS were 50, 26.5 and 7.8%, respectively. ENA1 was the most common EN found with a percentage of contamination of 39%, levels ranged between 14 and 445 mg/kg. ENB contaminated 14 samples (21.8%) and levels ranged from 5 to 100 mg/kg. ENB1 was present in four samples (6.2%) and levels varied from 8 to 32 mg/kg. ENA was detected in only one sample with 34 mg/kg. BEA levels ranged from 1 to 59 mg/kg and FUS levels varied from 0.6 to 2 mg/kg. The present report is the first one ever drafted on the presence of emerging Fusarium mycotoxins in raw cereals available in Morocco.     

A sensitive HPLC-MS/MS screening method for the simultaneous detection of lupine,pea, and soy proteins in meat products

The use of vegetable proteins in various types of meat products is common practice. In order to control food specifications, also with regard to food fraud and allergenic potential, a reliable detection of these additives is required. Here, a sensitive screening method for the simultaneous detection of lupine (Lupinus angustifolius), pea (Pisum sativum), and soy (Glycine maxima) in meat products applying High Performance Liquid Chromatography-Tandem Mass Spectrometry (HPLC-MS/MS) has been developed. After protein extraction and tryptic digestion, 3 to 4 marker peptides for each plant species were measured by HPLC-MS/MS. For matrix calibration, emulsion-type sausages with 0, 1, 6, 32, 160, 800, and 4000 mg/kg raw legume protein isolates/legume flour were produced. The mentioned legumes were detectable in sausages with concentrations of 6 mg/kg legume protein isolates/legume flour or greater. High correlation coefficients (R² > 0.999) between the peak areas of the mass transitions of the marker peptides and the contents of legume proteins in the meat products were obtained. The limits of detection (LODs) of the method were about 5 mg/kg meat product for pea protein, 4 mg/kg meat product for soy protein, and 2 mg/kg meat product for lupine protein. No false-positive or false-negative results were recorded. The applicability of the described method was tested by analyzing commercial meat products with and without added legume proteins.     

Biogenic amines in commercial fish and fish products sold in southern China

Eight biogenic amines (histamine, tryptamine, putrescine, 2-phenylethylamine, cadaverine, tyramine, spermidine and spermine) were determined in 13 species of fish and 49 fish products commonly consumed in southern China. The biogenic amines were analyzed by reverse phase HPLC with a fluorescence detector following pre-column derivation with dansyl chloride. In the fish samples, the total level of biogenic amine (BA) ranged from 5.03 mg/kg to 156.17 mg/kg, with a mean value of 44.17 mg/kg. Histamine levels were less than 21.85 mg/kg. The BA levels detected were not high enough to indicate fish decomposition. Low BA levels were also found in most fish product samples. However, several samples of fermented fish products and packaged fish products showed higher levels (484.42 mg/kg of BA in lightly cured horse mackerel and 166.45 mg/kg of BA in packaged eel). Specifically, lightly cured horse mackerel, which is a traditional fish product in southern China, exhibited relatively high levels of 2-phenylethylamine (57.61 mg/kg), cadaverine (244.41 mg/kg) and tyramine (62.85 mg/kg). Such samples with relatively high BA content require careful monitoring to ensure their safety for human consumption.     

1H NMR,Rheology, and Bottle Testing of HPAm/Cr(III) Acetate Micro Gels

Abstract

Solutions formulated at 40°C with partly hydrolyzed polyacrylamide (HPAm) and Cr(III) acetate 50% active were monitored for 240 hr using ¹H nuclear magnetic resonance (¹H NMR). The HPAm concentration was kept constant at 2,500 mg/L (which is slightly below the critical polymer concentration) and the HPAm to Cr(III) acetate weight ratio ranged from 5:1 to 60:1. Changes in the ¹H NMR transverse relaxation (T ₂) of the solutions were dominated by the chemistry of Cr(III) acetate. ¹H NMR detected changes immediately after HPAm started reacting with Cr(III) acetate. These changes were undetectable by rheology or bottle testing of the studied solutions.     

新型双苯并咪唑润滑油添加剂的合成及其多效性能研究

以邻苯二胺、溴代叔丁烷和硫代二乙酸为原料,合成新型润滑油添加剂1,3-二(1-叔丁基-2-苯并咪唑)-2-硫代丙烷(tBu-BIMS),采用MS,FTIR,1H NMR等方法对产物进行了分析和表征;并通过挂片失重实验和四球摩擦实验考察了其作为润滑油添加剂对Q235钢的缓蚀性能和抗磨减摩效果。实验结果表明,在硫含量为0.2 mg/g的石油醚溶液中,tBu-BIMS对Q235钢具有良好的缓蚀性能,当tBu-BIMS添加量为5×10-5 mol/L时,缓蚀率达到90%以上;将tBu-BIMS作为以菜籽油为基础油的润滑油添加剂,可明显减小菜籽油的摩擦系数和钢球的磨斑直径,当菜籽油中tBu-BIMS质量分数为0.75%时,钢球的磨斑直径减小了30.88%。     

含荧光基团的丙烯酸-丙烯酰胺共聚物的合成

以4-氯-1,8-萘二甲酸酐和3-二甲氨基丙胺为原料合成了一种水溶性的荧光单体4-甲氧基-N-(2-N,′N′-二甲基氨基丙基)萘二甲酰亚胺烯丙基氯化铵(4-MNDMAPN-AQ),并得到了最佳的合成条件。通过红外光谱、核磁共振谱、质谱等方法对产物结构进行了表征。将该荧光单体与丙烯酸(AA)、丙烯酰胺(AM)共聚,得到了共聚物AA/AM/4-MNDMAPN-AQ。对该共聚物的荧光性质和阻垢性能进行了系统研究,结果表明,该共聚物的荧光强度与其质量浓度呈良好的线性关系,线性相关系数为0.995 0,检测下限为0.48m g/L。采用硬垢法,在(75±0.2)℃、[Ca2+]=5mm ol/L、[HCO3-]=10mm ol/L、恒温10h、共聚物AA/AM/4-MNDMAPN-AQ的质量浓度为2.5m g/L的条件下,该共聚物的阻垢率可达70.78%,与阻垢性能良好的2-膦酸基丁烷-1,2,4-三羧酸相当,达到了阻垢剂的阻垢分散性能要求,表明该共聚物具有良好的阻垢性能。     

Monitoring the contents of biogenic amines in fish and fish products consumed in Korea

In order to obtain the level of biogenic amines in fish and fish products, a reversed phase high performance liquid chromatographic method was used for the quantitation of 12 biogenic amines in 300 fish and 80 fish products in Korea. Biogenic amines were extracted with hydrochloric acid, derivatized with dansyl chloride, separated using gradient elution, and detected by photodiode array and all detected biogenic amines were identified by UPLC/MS/MS. The detection levels of biogenic amines in the sample ranged from ND (not detected) to 30.6 mg/kg for agmatine, from ND to 390.0 mg/kg for cadaverine, from ND to 19.8 mg/kg for dopamine, from ND to 70.1 mg/kg for histamine, from ND to 17.8 mg/kg for noradrenaline, from ND to 29.7 mg/kg for 2-phenylethylamine, from ND to 43.0 mg/kg for putrescine, from ND to 11.9 mg/kg for serotonin, from ND to 9.5 mg/kg for spermidine, from ND to 13.5 mg/kg for spermine, from ND to 12.8 mg/kg for tryptamine, and from ND to 67.7 mg/kg for tyramine. Anchovy samples showed the high levels of histamine from 15.2 to 70.1 mg/kg, putrescine from 9.1 to 43.0 mg/kg, cadaverine from 152.2 to 90.0 mg/kg, and tyramine from 27.1 to 67.7 mg/kg. Agmatine was found at 30.6 mg/kg in cuttlefish. In the others fish samples agmatine detection levels were in the range from ND to 27.2 mg/kg. Spermidine and dopamine were detected about more than 85% samples in the range from ND to 19.3 mg/kg. Most of fish product samples showed less than 20 mg/kg of each biogenic amine. The maximum histamine and tyramine detection levels were respectively less than those of the regulation and recommendation.     

Determination and occurrence of 5-hydroxymethyl-2-furaldehyde in white and brown sugar by high performance liquid chromatography

5-hydroxymethyl-2-furaldehyde (HMF) is not only indicator of food freshness and quality, but also contaminant forming during Maillard reaction, or by dehydratation of saccharides, respectively. While data about presence of HMF in white and brown sugar are scarce, 13 kinds of white sugar and 25 kinds of brown sugar were analysed. Sugar was dissolved in deionised water, clarified with Carrez solutions, filtered and content of HMF was determined using high performance liquid chromatography with diode array detector (HPLC-DAD) with detection at 284 nm when separation run on Poroshel 120 EC C18 at 32 °C. Elution was performed under isocratic conditions using 95:5 water/acetonitrile mobile phase at a flow rate of 0.9 mL/min and analysis run 5 min. Method was validated in in house regime and its parameters such as limit of detection – (LOD = 0.05 mg/kg), limit of quantification (LOQ = 0.15 mg/kg), specificity, repeatability and recovery enabled its application for sugar analysis. While white sugar was free of HMF, all kinds of brown sugar exhibited presence of HMF, when content in 15 kinds varied between 0.17 and 6.45 mg/kg, content in other 10 kinds was under LOQ. On the base of obtained results was postulated that brown sugar contains HMF either due to absence of refining processes, or it is re-contaminated by treacle adding to white sugar during production of brown sugar.     

Monitoring the contents of biogenic amines in sufu by HPLC with SPE and pre-column derivatization

Sufu is a nutritious fermented food whose consumption is currently increasing in many countries. The purpose of this study was to develop an HPLC method with SPE and pre-column derivatization for monitoring the content of biogenic amine in sufu and to understand the differences in the contents of biogenic amines with different processing technologies. Biogenic amines in sufu were extracted with 6% trichloroacetic acid, derivatized with 4-chloro-3,5-dinitrobenzotrifluoride, purified with Waters Oasis MCX cartridge, separated by HPLC using gradient elution, and detected by spectrophotometric UV at 254 nm. The method linearity, calculated for each biogenic amine, has a correlation coefficient higher than 0.9915. Detection limits of the biogenic amines were ranged from 0.016 mg/kg for putrescine to 0.067 mg/kg for spermine. Spiking experiments showed that the overall recoveries ranged between 83.6% and 103.5% with relative standard deviations of 1.26–5.24%. Of the seven biogenic amines under study, at least four biogenic amines were detectable in different kinds of sufu. Tryptamine, putrescine, histamine, and tyramine were the most prevailing biogenic amines in all sufu samples. The mean values of histamine, tryptamine, phenylethylamine, tyramine, putrescine, spermidine and spermine determined in samples were found to be 18.2 mg/kg, 39.0 mg/kg, 1.1 mg/kg, 21.7 mg/kg, 34.6 mg/kg, 11.1 mg/kg, and 8.7 mg/kg, respectively. The total contents of biogenic amines in bacteria fermented sufu samples (129.0 mg/kg) were slightly lower than those in enzymatically ripened sufu samples (137.7 mg/kg). The concentrations of biogenic amines detected in sufu samples were below the maximum permissible limits.     

对二甲苯富氧氧化工艺研究

对BP-Amoco工艺氧化反应器进行了改进,以富氧空气为氧化剂对对二甲苯(PX)进行氧化反应,研究了反应器结构对氧化反应的影响,确定最佳的PX富氧氧化反应器结构为:反应器内有双层导流筒,进气口在导流筒外侧,进液口在导流简内侧,进气管内径10 mm。同时考察了富氧空气中的氧气含量、反应压力对氧化反应的影响,得到了适宜的工艺条件:富氧空气中氧气体积分数为24 0%～27.0%,反应压力1.50 MPa,反应温度195.0℃,搅拌转速550 r/min,催化剂中w(Co)=230 mg/kg、w(Mn)=340 mg/kg、w(Br)=760mg/kg,进液流量55.0 kg/h,进气流量140～200 L/min,w(HAc+H_2O):w(PX)=3.7。在此条件下,PX氧化反应效果最好,产物中目标产物对苯二甲酸含量高于普通空气氧化法,而主要副产物对羧基苯甲醛含量低于普通空气氧化法。