固相微萃取技术在果蔬农残检测中的应用研究

[目的]研究固相微萃取技术在果蔬农残检测中的应用,建立合适的测定果蔬中农药残留的分析方法。[方法]以3-氨丙基三乙氧基硅烷为功能单体,水胺硫磷为模板分子,采用溶胶-凝胶方法制备了分子印迹固相微萃取萃取头,建立分子印迹固相微萃取(MISPME)与气相色谱(GC-NPD)联用测定果蔬中5种有机磷的分析方法。[结果]试验得出,制得的分子印迹固相微萃取头对果蔬基质中的目标物具有很高的萃取量。分子印迹固相微萃取-气相色谱法方法的线性范围在μg/kg级别,相关系数大于0.994,检出限在0.01~1.33μg/kg,5次重复加标试验所得RSD在1.77%~9.28%,在真实样品中的加标回收率为88.5%~107.2%。[结论]分子印迹固相微萃取与气相色谱联用测定果蔬中有机磷的方法简单、快速,无需溶剂,准确度高,具有广阔的应用前景。     

水胺硫磷分子印迹固相微萃取涂层的制备及在果蔬水胺硫磷农药检测中的应用

以聚乙二醇为功能单体,水胺硫磷为模板分子,采用溶胶G凝胶技术,制备水胺硫磷分子印迹固相微萃取涂层,并建立顶空固相微萃取与气相色谱(HSGSPME/GC)联用检测果蔬中水胺硫磷残留量的方法.结果表明,制备的印迹涂层对水胺硫磷具有较高的选择性,且萃取能力大大高于非印迹涂层及常用商用涂层;在最优条件下,建立的方法在10~10000μg/kg范围内线性相关系数为0.9996,检出限为5.6μg/kg,5次重复实验所得相对标准偏差为2.29%;应用该方法测定黄瓜、西红柿、苹果、梨和大白菜等5种果蔬基质中水胺硫磷含量时,均未有水胺硫磷检出,在5种基质中加标回收率均在89.4%~106.6%之间.     

基于气相色谱-质谱联用法的绿茶8种农药残留的同时检测（英文）

为了提高茶叶农药残留的检测效率,该研究从提取溶剂的选择、净化条件、线性回归、回收率及精密度等方面着手,开展了基于气相色谱一质谱联用法的绿茶中8种农药残留的同时检测研究。结果表明,在以乙腈为提取溶剂、以活性炭和PSA串联柱为固定相、以乙腈为洗脱剂、洗脱体积为12 ml的检测条件下,莠灭净在0~100μg/L范围,敌草胺在0~10 000μg/L范围,其余农药在0~1 000μg/L范围内,峰面积与样品质量浓度呈线性关系,相关系数均大于0.999。以茶叶农药残留量限值为添加量,重复测定6次,备农药平均加标回收率在73.6%~116.8%,相对标准偏差范围在1.47%~15.58%。说明该研究所建立的检测方法灵敏度高、选择性好、抗干扰能力强,可在茶叶多农残检测中推广应用。     

气相色谱-串联质谱法测定动物组织中6种β-受体激动剂残留量研究

建立了气相色谱-串联质谱同时测定动物组织中6种β-受体激动剂(克伦特罗、溴布特罗、马布特罗、莱克多巴胺、特布他林、沙丁胺醇)残留量的检测方法。样品经乙酸乙酯提取,SCX小柱提取净化后,用BSTFA:TMCS衍生,再进行气相色谱-串联质谱测定,在子离子扫描模式下优化不同β-受体激动剂的碰撞能量。结果表明:该方法的相关系数为0.994~0.998,定量限为0.24~0.30μg/kg,检出限为0.08~0.10μg/kg,克伦特罗的线性范围为0.005~2.500μg/mL,溴布特罗的线性范围为0.002~3.000μg/mL,马布特罗、莱克多巴胺、特布他林的线性范围均为0.005~3.000μg/mL,沙丁胺醇的线性范围为0.010~2.000μg/mL。6种β-受体激动剂的回收率为79.7%~100.3%,精密度为1.2%~3.3%。     

基质固相分散—气质联用法快速检测黄瓜中四类农药残留

基于基质固相分散(matrix solid-phase dispersion,MSPD)前处理方法和气相质谱联用技术,通过优化前处理以及气相质谱方法,建立了同时测定黄瓜中有机磷、有机氯、拟除虫菊酯和氨基甲酸酯4类常见农药多残留的方法。结果表明,50种农药在50~1 000μg·L-1范围内线性关系良好,相关系数为0.973 0~0.999 7,且大部分在0.99以上,各农药上机定量下限为1~2μg·kg-1。10和50μg·kg-1两个水平的50种农药加标回收试验表明,加标水平为50μg·kg-1时,农药回收率全部在70%~100%,10μg·kg-1水平时,有45种农药回收率在70%~100%,相对标准偏差为0.23%~15.42%。该方法灵敏度高,快速简单,准确可靠,适用于黄瓜中4类常见农药多残留的日常检测工作。     

土壤中二苯醚类残留物质的前处理方法研究

为了建立一种简单便捷的处理土壤中二苯醚类物质残留的的前处理方法,对比研究了超声萃取、索氏提取、分散固相萃取以及加速溶剂萃取(ASE)4种前处理方法的试验条件,最终建立了样品加入0.1%乙酸的乙腈提取、50 mg C18净化的分散固相萃取进行样品预处理、GC-MS气相色谱质谱法测定的方法。在添加浓度为50、200μg/kg下,空白土壤的加标回收率为76%~111%,相对标准偏差在4.6%~11.8%,方法检出限为3.5~10.5μg/kg,可以满足对残留分析的要求。     

水胺硫磷分子印迹固相微萃取涂层的制备及在果蔬水胺硫磷农药检测中的应用

以聚乙二醇为功能单体,水胺硫磷为模板分子,采用溶胶-凝胶技术,制备水胺硫磷分子印迹固相微萃取涂层,并建立顶空固相微萃取与气相色谱(HS-SPME/GC)联用检测果蔬中水胺硫磷残留量的方法。结果表明,制备的印迹涂层对水胺硫磷具有较高的选择性,且萃取能力大大高于非印迹涂层及常用商用涂层。在最优条件下,建立的检测方法在10～10 000μg/kg范围内线性相关系数为0.999 6,检出限为5.6μg/kg,5次重复实验所得相对标准偏差为2.29%。应用该检测方法测定黄瓜、蕃茄、苹果、梨和大白菜等5种果蔬基质中水胺硫磷含量时,均未有水胺硫磷检出,在5种基质中加标回收率均在89.4%～106.6%之间。     

液液萃取-固相萃取气相色谱法测定火腿中有机磷农药残留量

[目的]建立火腿中多种有机磷农药残留量同时测定的方法。[方法]火腿中有机磷农药经乙腈提取后,用乙腈-正己烷液液萃取除去脂类和色素,再经石墨碳黑固相萃取小柱净化,气相色谱-火焰光度检测器(GC-FPD)测定。[结果]16种有机磷农药在DB-17、DB-1色谱柱上均获得良好分离,在0.05~1.00μg/m L范围内,农药残留量色谱分析的线性关系良好,满足定量分析要求,加标水平为0.08和0.20 mg/kg时,农药的平均回收率在71.96%~117.21%,变异系数为1.73%~12.84%。方法的检出限为0.005 3~0.011 8 mg/kg。[结论]该方法具有前处理简单、净化效果好、方法准确、灵敏度高、杂质干扰少的特点,适合火腿中有机磷农药残留量的分析。     

气相色谱-质谱法测定枸杞中28种农药残留

建立了气相色谱-质谱法检测枸杞中28种农药残留的分析方法。样品经乙腈提取,carb/NH2固相萃取柱净化,DB-17MS(30 m×0.25 mm×0.25μm)色谱柱分离,选择离子监测模式(SIM)检测,外标法定量。结果表明,28种农药在0.01~5.00μg/m L范围内呈良好线性(r20.99),方法检出限为0.008~0.085μg/g,定量限为0.027~0.280μg/g,加标回收率为71.0%~106.0%,相对标准偏差为0.96%~12.30%。该方法灵敏度高、定性定量准确,可满足枸杞样品中农药多残留的检测要求。     

分散固相萃取-超高效液相色谱-串联质谱法检测砂仁中15种有机磷类农药

建立了分散固相萃取-超高效液相色谱-串联质谱检测砂仁中15种有机磷类农药残留量的方法,并对16个不同产地的砂仁药材进行农药残留测定。砂仁样品经乙腈(含1%甲酸)提取和盐析剂盐析后加入N-丙基乙二胺(PSA)、十八烷基键合硅胶吸附剂(C18)和无水硫酸镁进行基质固相分散萃取、净化,采用超高效液相-串联质谱在多反应检测模式(MRM)下测定,外标法定量。15种农药成分在0.005~0.100 mg/L有良好的线性关系,相关系数在0.999~1.000; 15种农药成分在3个添加水平下(100、 200和400μg/kg),加标回收率范围为70.0%~120.0%, RSD%(n=3)为0.5%~9.5%;各农药成分的检出限在0.1~2.0μg/kg。该方法可应用于多产地的砂仁药材中15种有机磷类农药残留的检测。     

Web2.0,以个人为中心的互联网时代的到来

本文介绍了Web2．0的知识和背景，对Web2．0出现的基础以及典型技术和应用作了阐述，同时对其作出了前景展望。     

盐胁迫对葡萄苗期多胺和激素代谢的影响

【目的】 研究盐胁迫条件下,葡萄叶片中多胺含量、多胺氧化酶、多胺合成酶活性以及激素的动态变化,研究不同盐胁迫强度对多胺类物质及激素代谢的影响。【方法】 采用盆栽基质培养模拟盐胁迫环境,设置4个NaCl处理梯度:0 (CK)、1、2和3 g/kg。多胺和激素含量的测定采用高效液相色谱法,多胺合成及分解酶活性的测定采用紫外分光光度计比色法。【结果】 盐胁迫处理后,葡萄叶片中多胺含量和脱落酸含量较对照而言显著增加,玉米素含量显著降低,随胁迫时间的延长,Put、Spm、Spd、ABA以及PAO、DAO、ADC、ODC、SAMDC活性均呈先上升后下降趋势,在10 d及10 d后达到峰值。ZT呈逐渐下降的趋势,并随胁迫强度增大而减小;进行显著性分析后,叶片中多胺含量与Put、Spm、Spd含量呈极显著正相关,DAO、ADC、ODC活性与Put含量呈显著正相关,PAO与SAMDC活性与Spm和Spd含量也呈极显著正相关。【结论】 3种多胺经酶的合成代谢后和激素共同缓解葡萄苗所遭受到的盐胁迫,期间主要发生作用的是多胺合成酶,盐胁迫下多胺与激素含量之间的变化关系也十分密切。     

市级综合气象信息分析与管理系统的设计与实现

以抚顺地区3个国家基本站50余年气象资料为依托,采用Microsoft Excel工作表实现由气候和农业气候2部分构成的气象与农业综合信息处理系统的基本思路、方法、内容、用途和使用情况。为了实现气候分析及应用的科学化、客观化、系统化、规范化、程序化及连续化的业务目标,按业务流程设计与实现的,包括资料处理、气候趋势模拟、气候预测、气候鉴定、季节性信息化处理、农作物产量预报、气候生产潜力分析等一系列内容在内的系统建设。关键是解决了大量的计算问题,建立了区域性通用模式。     

Multi-variable grey model (MGM (1,n,q)) based on genetic algorithm and its application in urban water consumption

Urban water consumption has some characteristics of grey because it is influenced by economy, population, standard of living and so on. The multi-variable grey model （MGM（1,n））, as the expansion and complement of GM（1,1） model, reveals the relationship between restriction and stimulation among variables, and the genetic algorithm has the whole optimal and parallel characteristics. In this paper, the parameter q of MGM（1,n） model was optimized, and a multi-variable grey model （MGM（1 ,n,q）） was built by using the genetic algorithm. The model was validated by examining the urban water consumption from 1990 to 2003 in Dalian City. The result indicated that the multi-variable grey model （MGM（1,n,q）） based on genetic algorithm was better than MGM（1,n） model, and the MGM（1,n） model was better than MGM（1,1） model.     

Molecular detection of virulence genes in Campylobacter species isolated from livestock production systems in South Africa

Campylobacter species are a major cause of foodborne bacterial infections in both developed and developing countries worldwide. Campylobacter jejuni is responsible for the majority of infections. This study was conducted to identify virulenceassociated genes in Campylobacter species isolated from livestock production systems in South Africa. A total of 250 fecal samples consisting of cattle(n=50), chickens(n=50), goats(n=50), sheep(n=50) and pigs(n=50) were randomly collected from livestock in Eastern Cape and KwaZulu-Natal provinces of South Africa between April and October 2018. The samples were analyzed for the presence of virulence genes in Campylobacter species using molecular PCR-based methods. It was found that 77 and 23% of Campylobacter jejuni and Campylobacter coli respectively were isolated from all the livestock samples. There were positive significant(P0.05) correlations amongst all the virulence genes that were investigated. Chisquare and Fisher's exact tests were implemented to test for the effect of livestock species on the presence or absence of virulence genes. The study demonstrated that most of livestock species can potentially cause zoonotic infections and food poisoning due to the high prevalence of Campylobacter. The high prevalence of virulence genes highlights the significance of Campylobacter in livestock production systems in South Africa. This requires the implementation of one-health approaches to reduce the impact of foodborne and zoonotic diseases for the welfare of human and animal health.     

红苕饲粮中添加铜和/或喹乙醇对猪生产性能及某些血液生化指标的影响

选体重约38公斤的长白(♂)×成华(♀)杂交猪20头,随机分为四组,饲予四种不同的饲粮,研究饲粮中添加铜和/或喹乙醇对猪生产性能和某些血液生化指标的影响。结果表明:基础组、加铜组、加喹乙醇组和两者同时加组全期日增重分别为674、761、796、678克,日采食量分别为2.50、2.65、2.74、2.40公斤,饲料利用率分别为3.73、3.49,3.44、3.54,添加铜和/或喹乙醇对试验第65天血清铜兰蛋白、尿素氨及屠宰率、背膘厚和眼肌面积无显著影响(p>0.05);添加铜使65天血清碱性碱酸酶活性极显著增高(p<0.01),添加喹乙醇有使之升高的趋势,两者同时添加时,碱性酸磷酶活性降低。     

不同施肥水平对木薯氮磷钾养分积累、分配及其产量的影响

 【目的】通过比较不同施肥水平下木薯氮磷钾养分积累、分配和产量的差异,探讨粤北坡岗地优质高产木薯氮磷钾养分的最佳用量。【方法】以木薯品种南美119为材料,采用“3414”方案,在粤北翁源进行大田试验。试验共设14个处理。【结果】施肥处理的氮素主要分配到地上部,不施肥处理的氮素则主要分配到根部;不同施肥处理的磷素均主要分配到地上部;不施肥处理和不施钾处理的钾素主要分配到根部,不施氮处理的钾素在根、冠间分配较均衡。在木薯不同生长阶段,植株氮磷钾含量均呈下降趋势,但施氮、磷、钾化学肥料处理植株氮磷钾含量的下降速度小于不施氮、磷、钾化学肥料的处理。处理N2P2K2的氮、磷、钾含量和积累量在各生育期均为最大,不施肥处理（N0P0K0）的氮、磷、钾含量和积累量在各生育期均为最小（P＜0.05）。产量最高的是N2P3K2处理,为22 694.06 kg·hm-2,其次是N2P2K2处理,为21 417.87 kg·hm-2。【结论】木薯产量、氮磷钾养分积累及其在根冠间的分配,对施肥水平高度敏感, 适当比例的氮磷钾肥配合施用既可以显著增加木薯植株的氮磷钾含量和积累量,又可以提高产量。在粤北坡岗地木薯生产中,氮素最重要,在氮素得到满足的条件下,磷素较钾素更重要。在本试验条件下,氮磷钾养分最佳用量为358.80 kgN·hm-2、89.10 kg P2O5·hm-2和187.50 kg K2O·hm-2。     

Current progress on genetic interactions of rice with rice blast and sheath blight fungi

Analysis of genetic interactions between rice and its pathogenic fungi Magnaporthe oryzae and Rhizoctonia solani should lead to a better understanding of molecular mechanisms of host resistance, and the improvement of strategies to manage rice blast and sheath blight diseases. Currently, dozens of rice resistance (R) genes against specific races of the blast fungus have been described. Among them, ten were molecularly characterized and some were widely used for breeding for genetic resistance. The Pi-ta gene was one of the best characterized rice R genes. Following the elucidation of its molecular structure, interaction, distribution, and evolution, user friendly DNA markers were developed from portions of the cloned genes to facilitate the incorporations of the Pi-ta mediated resistance into improved rice varieties using marker assisted selection (MAS). However, rice blast is still a major threat for stable rice production because of race change mutations occurring in rice fields, which often overcome added resistance based on single R genes, and these virulent races of M. oryzae pose a continued challenge for blast control. For sheath blight, progress has been made on the exploration of novel sources of resistance from wild rice relatives and indica rice cultivars. A major quantitative trait locus (QTL), named qSB9-2, was recently verified in several mapping populations with different phenotyping methods, including greenhouse methods. The ability to identify qSB9-2 using greenhouse methods should accelerate the efforts on the qSB9-2 fine mapping and positional cloning.     

Virus Location and Lymphocyte Apoptosis in Lymph Nodes of Piglets Infected with PCV-2

The present study has been performed to understand the location of the virus, type of apoptotic cells, and their relation to lymph nodes of piglets infected with porcine circovirus type Ⅱ （PCV-2）. Nine 32-day-old conventional piglets free of infection with PCV-2 were used, and distributed into three groups： control group （n = 3）, piglets inoculated with PCV-2 alone （PCV-2, n = 3）, and PCV-2 inoculated and KLH immunostimulated group （PCV-2 ＋ KLH, n = 3）. Superficial inguinal lymph nodes from all piglets were collected for histological examination after 32 days postinoculation, and immunohistochemistry for PCV-2 detection. Location of apoptotic cells was detected with TdT-mediated dUTP nick end labeling （TUNEL） and cell cycle, and the apoptotic rates were measured by flow cytometry. The characteristic histopathological lesions of the piglets in PCV-2 and PCV-2 ＋ KLH were lymphocyte depletions in the cortex and paracortex of the lymph nodes, epithelioid-like macrophage infiltration, and intracytoplasmic inclusion bodies presented in epithelioid-like macrophages. PCV-2 was mainly found in epithelioid-like macrophages by immunohistochemistry. In the lymph nodes, lymphocytes presented higher apoptotic rates in the cortex by TUNEL, special B-cell areas, and similar apoptotic cells were found in this compartment in the control. The apoptotic rates of the lymph nodes were 0.41, 3.34, and 4.88% in the control, PCV-2, and PCV-2 ＋ KLH groups by flow cytometry, respectively. The apoptotic rates of lymph nodes for PCV-2 and PCV-2 ＋ KLH piglets were significantly higher than those for the control group （P〈0.05 and P〈0.01）. The proliferation index （PI） was 0.17_＋0.01, 0.12_＋0.01 and 0.12_＋0.04 in the control, PCV-2, and PCV-2 ＋ KLH group, the PI of the control group was higher than that of the other groups, but without the statistical difference. PCV-2 can induce lymphocyte depletion in lymph nodes of piglets by blocking cell proliferation and promoting apoptosis. This is one o     

内脐蠕孢属、平脐蠕孢属和凸脐蠕孢属的研究

本文报道了平脐蠕孢属(Bipolaris)一个新种,一个新组合,5个新记录以及凸脐蠕孢属(Exserohilum)一个新记录。讨论了内脐蠕孢属(Drechslera)、平脐蠕孢属、凸脐蠕孢属与长蠕孢属(Helminthosporium)的关系,并就我国已报道的长蠕孢属真菌按Alcorn等~([1,3,4,5,24])人的意见,逐个进行了订正。