GC法测定核桃油中的酚类抗氧化剂的不确定度分析

目的：建立气相色谱法测定山核桃油中酚类抗氧化剂的不确定度评定数学模型,分析试验中不确定度来源。方法：样品经过乙酸乙酯稀释,采用气相色谱法测定山核桃油中BHA、BHT、TBHQ的含量,计算合成不确定度和扩展不确定度。结果：山核桃油中BHA、BHT、TBHQ的扩展不确定度分别为0.097、0.093 8、0.096 6 mg/kg（k=2,P=95%）。结论：影响3种抗氧化剂气相色谱法测定的不确定度来源主要是标准曲线溶液配制、标准曲线拟合和样品定容步骤,此不确定度评定可以提高检测结果的准确性。     

气相色谱法测定啤酒中的游离脂肪酸

气相色谱法测定啤酒中辛酸到二十二碳酸共１１种游离脂肪酸,采用多级溶剂萃取及薄层色谱纯化技术进行样品制备,并采充氮措施抑制脂肪酸的氧化产生,此方法有较好的重复性和回收率。     

气相色谱法测定抗毒素中的间甲酚含量

采用气相色谱法测定抗毒素中的间甲酚含量。样品用苯甲醇作内标,经高氯酸沉淀蛋白、氯仿抽提后,通过HP-INNO-WAX柱,以氢火焰检测器测定间甲酚含量。内标峰与样品峰的分离度大于1.5,平均回收率及变异系数分别为100.067%和1.93%,测定线性范围0.0202~1.7588mg/ml,最小检测限为0.01272mg/ml,该方法准确快速,比化学方法好。     

天然食品抗氧化剂的研究进展

综述了目前几种天然抗氧化剂种类的开发与应用,并探讨了国内外天然食品抗氧化剂的未来发展趋势。     

气相色谱法测定CO2释放速率

采用红外分析仪测定CO_2时,常发生水分干扰,且测定时间长。本文采用气相色谱法测定CO_2,具有快速、准确、灵敏度高和操作简单等特点。     

气相色谱法测定结核菌耐药性的研究

本文应用气相色谱法对结核菌的耐药性进行了研究。在与传统法对比试验中,两法符合率为86.4%。气相色谱法可在6天报告比较准确的结果,比传统试管法提前2周,提示此法有较大的实用价值。     

分析粮谷类食品中联苯菊酯的气相色谱检测

菊酯类农药出现于上个世纪60年代,其属于一类新型杀虫剂,其具备高效、对农作物安全、低残留等特点。联苯菊酯为拟除虫菊酯类杀虫杀螨剂,其具备触杀及胃毒作用。联苯菊酯凭借自身持效期长及防治谱广等特点而被广泛应用于现代农业生产中。但因部分联苯菊酯残留于农作物上而导致人畜中毒现象时有发生,人体健康也因此受到极大威胁。     

气相色谱法测定二高γ-亚麻酸

本文建立了一种测定二高γ-亚麻酸气相色谱方法,色谱条件为L=300mm长的毛细管柱,柱温230℃,FID检测器。样品的线性范围为10-30μg,精密度和重现性的RSD分别为1．45％和1．15％,回收率为98．96％,RSD为1．47％。     

活体植物根瘤固氮酶活性的气相色谱法测定

本文改进了利用气相色谱分析活体豆科植物根瘤内根瘤菌固氮酶活性的方法,该方法比用传统的测量离体根瘤的方法所得结果更接近共生体的实际水平。本试验使用国产仪器和材料,组装了一个适合测量大豆(Glycine max)、野大豆(Glyeine soja)-大豆根瘤菌(Bradyrhizobium japonicum/Sinothizobium fredii)共生体完整植株根瘤固氮活性的装置。其特点是不损伤被测植株,并在植物正常进行光合作用的同时测量根瘤固氮酶活性,还可同步测量植株的光合作用和呼吸作用,特别适于研究共生体的连续变化。应用此装置侧量的结果与国外使用的全自动定型仪器的侧量结果一致。     

气相色谱法测定RuBp羧化酶活性的研究

ＲｕＢｐ羧化酶作用后反应体系中能为加入的ＨＣｌ释放出的剩余,作为ＲｕＢｐ羧化酶活性指示。所释放的ＣＯ＿２以气相色谱法检测,用黄瓜叶片中ＲｕＢｐ羧化酶的反应时间曲线和酶量曲线验征,并与现行的分光光度,￣（１４）Ｃ标记测试方法比较分析,认为本方法具有应用简便、快速、准确、重复性好等优点。所以,可被认为是一种有效的测定ＲｕＢｐ羧化酶活性的方法。     

石墨炉原子吸收光谱法测定虾产品中铝的方法研究

目的:本文着重研究利用石墨炉原子吸收光谱法测定虾产品中铝,对测定条件进行优化选择,达到快速、准确,以弥补国家标准检测方法中没有虾产品中铝检测方法的不足。方法:利用混合酸硝酸-高氯酸对样品进行消化处理,无基体改进剂,利用石墨炉原子吸收光谱仪进行定量检测。结果:在优化干燥、灰化、原子化、除残四个步骤的时间和温度的实验条件后,铝含量在0.0-50.0μg/L范围内呈线性关系,相关系数达到r=0.9990,最低检出限为0.54 ng/mL,铝的特征质量为5.0 pg。相对标准偏差为3.83%-6.42%,虾产品中铝含量测定回收率为90.7%-105.6%。结论:本法方便准确,灵敏度高,并有较高的回收率,可作为日常检测使用。     

湿式消解-石墨炉原子吸收光谱法测定金线莲铅、铜、镉含量

采用湿式消解法对金线莲药材进行处理,石墨炉原子吸收光谱法测定其铅(Pb)、铜(Cu)、镉(Cd)等重金属元素含量。结果表明,Pb、Cu、Cd 三种元素的原子化温度分别是2100、2200和1800 ℃,灰化温度分别是400、800和250 ℃。Pb、Cu、Cd三种元素的检出限分别为0.47、0.50、0.62 μg·L-1,其加标回收率在92.7%～94.0%之间,平均相对标准偏差为1.71%,说明仪器精密度良好,湿式消解-石墨炉原子吸收光谱法能有效测定金线莲药材中Pb、Cu、Cd含量。     

Effects of butylated hydroxyanisole,butylated hydroxytoluene and tertiary butylhydroquinone on growth and luteoskyrin production byPenicillium islandicum

Butylated hydroxyanisole (BHA), Butylated hydroxytoluene (BHT) and tertiary butylhydroquinone (TBHQ) alone in cultural media were tested for the inhibition of growth and luteoskyrin production by two toxigenic strains ofPenicillium islandicum UST-11 andP. islandicum HLT-6. In potato dextrose agar, the concentrations of BHA and TBHQ from 0.2 mg/disc, BHT from 5.0 mg/disc did affect the growth of both tested strains, but the initial concentrations of these antioxidants to reduced luteoskyrin production by UST-11 strain were BHA 0.5 mg/disc, BHT 1.0 mg/disc and TBHQ 0.4 mg/disc, while for HLT-6, BHA 0.4 mg/disc, BHT and TBHQ were 0.2 mg/disc, respectively. In grainy and powdery rice media, the effects of BHA, BHT and TBHQ on luteoskyrin production byP. islandicum UST-11 and HLT-6 were clearly demonstrated. The efficiency of the inhibitory effect was not only closely related to the concentration of antioxidants, but also completely inhibited the luteoskyrin production at a concentration of 200 mg/kg or higher. Also, the antioxidants at a concentration higher than 20 mg/kg reduced significantly the growth and luteoskyrin production by both strains ofP. islandicum.     

气相色谱法测定猪结肠内容物中短链脂肪酸含量

目的:为了准确测定猪结肠内容物中蛋白质代谢物短链脂肪酸含量以研究猪结肠蛋白质代谢情况,本文拟利用气相色谱建立一种更准确快速分析猪结肠内容物中短链脂肪酸含量的方法。方法:实验选用体重相近的21日龄断奶的杜长大三元杂交仔猪,单栏饲养。试猪麻醉后放血致死,迅速剖开腹腔,收集结肠末端内容物,保存于-80℃。收集到的结肠末端内容物用偏磷酸预处理,利用毛细管气相色谱法程序升温测定猪结肠内容物中短链脂肪酸含量。结果:结肠内容物经偏磷酸预处理3 h后,在程序升温、0.8 m L/min载气流量的气相色谱条件下,内容物中乙酸、丙酸、异丁酸、丁酸、异戊酸和戊酸得到有效分离,其回收率为93%~113%,相对标准偏差为0.46%~0.70%,变异系数小于1%。结论:此方法具有操作简便、快速、准确的优点,是测定动物肠道内容物中短链脂肪酸较为理想的方法。     

Modification of a Reaction Vessel for the Determination of Total Mercury in Hair by Cold Vapor Atomic Absorption Spectrometry

A classical cold vapor atomic absorption spectrometric (CVAAS) method for the determination of total mercury in blood has been previously adapted for application to samples of human hair. The reaction vessel specified in the original adaptation was, however, large and difficult to use with small hair samples. In the present study, the reaction vessel has been modified and reduced in size and the protocols have been optimized in order to provide an analytical method that is more efficient, less time-consuming, and gives lower blank values than the original adaptation. The optimized method was validated by multiple, independent, replicated assays of certified reference hair samples, and the mean recovery obtained (98.7%) indicated an efficient performance of the digestion and detection processes. The method was applied to the assay of 144 hair samples derived from populations that had or had not been exposed to mercury from environmental sources. The results from all of the samples analyzed were consistent with those published previously for similar samples.     

富含绿原酸的植物中类黄酮测定方法探讨

以枇杷花、枇杷叶和金银花为材料,研究绿原酸干扰类黄酮测定的结果表明,差示分析法基本上不受绿原酸的干扰,可用于富含绿原酸植物中类黄酮的测定;而NaNO_2-Al(NO_3)_3比色法和二甘醇比色法均受绿原酸的严重干扰,测得的类黄酮含量明显偏高,NaNO_2-Al(NO_3)_3比色法测得的结果甚至超过总酚含量。     

A Rapid Method,Combining Microwave-Assisted Extraction and Gas Chromatography-Mass Spectrometry with a Database,for Determining Organochlorine Pesticides and Polycyclic Aromatic Hydrocarbons in Soils and Sediments

A rapid method for determining organochlorine pesticides and polycyclic aromatic hydrocarbons in soils and sediments was developed to allow pollution surveys to be performed in emergencies. The method involves microwave-assisted extraction and uses an automated identification/quantification system with a gas chromatography mass spectrometry database. A sample (3 g) is extracted with a 3:2 v/v hexane:water mixture (10 mL) for 30 min using a microwave-assisted extraction system at 120°C. The hexane extract is then cleaned using silica gel, then analyzed by gas chromatography mass spectrometry. The total analysis time is approximately 4 h. The precision of the quantitative results and accuracy of the analyte identification were determined. The total analyte concentrations were generally comparable to (61%–110% of) the concentrations determined using a Soxhlet extraction method, but the concentrations of individual high-molecular-weight polycyclic aromatic hydrocarbons were unacceptably low compared with the concentrations determined using the Soxhlet method. However, these compounds (e.g., benzo(ghi)perylene and indeno(1,2,3-cd)pyrene) were subsequently efficiently extracted using a hexane:water:ethanol mixture. The accuracy of identification was evaluated using accurate masses determined by gas chromatography time-of-flight mass spectrometry, and the mass error was 2 ppm for 21 of the 22 compounds identified using the new method.     

动物线粒体DNA提取简易流程及其优化

目的:研究动物线粒体DNA(mtDNA)提取的简易流程,以提取到纯度高、结构完整的动物mtDNA。方法:采用SDS碱变性法,从动物的肝脏和性腺等组织中提取mtDNA,并增加了DNaseⅠ、RNase消化步骤,以除去核DNA及RNA的污染;用紫外分光光度计分析mtDNA的纯度和得率。结果:mtDNA的得率为0.5～0.8μg/g,D260nm/D280nm值为1.77～1.82,能满足对mtDNA进行RFLP分析、RAPD分析、测序分析等的要求。结论:改进的动物mtDNA提取方法简便可行,值得推广。     

西洋参不同部位皂苷类成分的指纹图谱研究

以西洋参（Panax quinquefolium L.）为材料,分别取主根、须根、芦头、参皮、参芯、茎、叶、花序、果实和芽孢等不同部位为材料,以高效液相法检测其皂苷类成分。利用系统聚类分析法和中药色谱指纹图谱相似度评价系统对各部位的皂苷种类和含量进行分析,将西洋参的不同部位按照成分组成进行了分类。