烟草化学成分的气相色谱-质谱分析及尼古丁含量的测定

采用同时蒸馏萃取法与水蒸气蒸馏法提取烟草中挥发性成分并用气相色谱-质谱（GC/MS）法分别确认其化学成分,其中主要成分为尼古丁.用气相色谱法测定烟草中尼古丁的含量.尼古丁含量在0.446 4～0.892 8 mg/mL范围内与峰面积呈良好线性关系,回归方程为：A=61 670 M-2 894.8,相关系数为0.998 6,回收率为99.83%.     

俄罗斯海参脂肪酸的气相色谱-质谱分析

为了解俄罗斯海参中脂肪酸的种类及组成,采用Bligh-Dyer提取法对样品中脂肪油进行提取,甲酯化后利用气相色谱-质谱联用仪进行分析测定．鉴定结果发现俄罗斯海参中含有25种脂肪酸,其中饱和脂肪酸8种,相对百分含量为22．45％;不饱和脂肪酸为17种,相对百分含量为77．53％,其中EPA和DHA的相对百分含量分别为9．46％和11．77％．     

粗煤气及清洗系统在本钢二铁厂六号高炉的应用

本钢6#高炉,2004年9月投产,容积2600m3,,高炉煤气除尘及清洗采用旋风除尘器及比肖夫煤气清洗系统,降低了煤气中的含尘量和含水量,有效提高了净煤气的发热值,同时顶压余压发电(TRT)系统更有效地进行了能源回收,降低了吨铁能耗,改善了煤气清洗系统的各项经济技术指标.     

金属热容量的研究

文章对金属热容量的经典统计理论、爱因斯坦理论、得拜模型理论进行了讨论,最后利用得拜模型理论,同时计及电子气体对金属热容量的贡献,使统计理论得到的结果能很好的解释实验结果.     

几种稻米中脂肪酸的研究

采用索氏提取法提取了泰国黑精米、白精米、辽宁大米及黑龙江大米中的脂肪酸,再进行甲酯化处理,利用气相色谱-质谱(GC-MS)法对其脂肪酸组成及含量进行了分析测定,结果表明:从黑精米、白精米、辽宁大米及黑龙江大米中鉴定出的脂肪酸分别占其总检出量的85.12%,93.77%,96.67%,99.48%,不饱和脂肪酸含量分别占到66.26%,65.69%,73.18%,73.98%,由此可知不饱和脂肪酸含量较高,所以稻米有很高的营养价值和开发前景.     

The interactive effect of exercise and immunosuppressant cyclosporin A on immune function in mice

Abstract

The determination of the ventilatory threshold has been a persistent problem in research and clinical practice. Several computerized methods have been developed to overcome the subjectivity of visual methods but it remains unclear whether different computerized methods yield similar results. The purpose of this study was to compare nine regression-based computerized methods for the determination of the ventilatory threshold. Two samples of young and healthy volunteers (n = 30 each) participated in incremental treadmill protocols to volitional fatigue. The ventilatory data were averaged in 20-s segments and analysed with a computer program. Significant variance among methods was found in both samples (Sample 1: F = 11.50; Sample 2: F = 11.70, P < 0.001 for both). The estimates of the ventilatory threshold ranged from 2.47 litres · min^?1 (71%[Vdot]O_2max) to 3.13 litres · min^?1 (90%[Vdot]O_2max) in Sample 1 and from 2.37 litres · min^?1 (67%[Vdot]O_2max) to 3.03 litres · min^?1 (83%[Vdot]O_2max) in Sample 2. The substantial differences between methods challenge the practice of relying on any single computerized method. A standardized protocol, likely based on a combination of methods, might be necessary to increase the methodological consistency in both research and clinical practice.     

Preparation of lyophilised lipid rich quality control serum by isolating lipids using large scale chromatography technology

The plasma fractionation is a technology to separate therapeutic plasma proteins. The fractionation is carried out either by solvent precipitation (ethanol) or recently by chromatography. During the process of chromatography lipids were found in waste fraction. A new lipid rich lyophilised quality control (Q.C.) sera was prepared inexpensively using this waste plasma fraction. This is probably the first attempt to prepare the Q.C. sera by large scale chromatographic method in India.     

气相色谱-质谱法测定饲料中莱克多巴胺

建立了简单、可靠的气相色谱-质谱联用测定饲料中莱克多巴胺的分析方法。试样用0.1mol／L高氯酸溶液提取,离心,中和,经乙酸乙酯-异丙醇萃取,浓缩后,用SCX固相小柱净化,4％浓氨水甲醇溶液洗脱、浓缩干,经N,O-双三甲基硅基三氟乙酰胺衍生,采用选择监测离子（m／z179、250、267、502）模式进行检测。实验结果表明,莱克多巴胺衍生物的峰面积与其浓度在20．0～1000μg／L范围内呈较好的线性关系,相关系数大于0．997;饲料试样在20．0、100和5000μg／kg三水平加标平均回收率在67．5％～92．3％,变异系数在3．0％～12％;方法检出限达5μg／kg。     

降低本钢烧结工序能耗的措施

本钢炼铁厂三烧360m^2烧结机在实施低硅烧结时出现了能源升高的情况,通过加强能源基础管理,挖掘节能潜力,不断提高烧结工艺技术水平和生产操作水平,减少故障时间,提高设备作业率,烧结固体燃耗、电耗、焦炉煤气消耗逐年降低,工序能耗取得了较好水平。     

HPLC法测定甲硝唑芬布芬胶囊的含量

目的：用高效液相色谱法测定甲硝唑芬布芬胶囊的含量。方法：用十八烷基硅烷键合硅胶为填充剂;以甲醇-乙腈-水（40：60：40）（用磷酸调节pH值至3．0）为流动相;检测波长为300nm;流速为1．0ml／min。结果：该方法在0．04080-0．2040mg／ml范围内,甲硝唑峰面积与质量浓度呈良好的线性关系。线性方程为y=3．8114E-08x-1．4259E-04,线性相关系数r=0．99999,在0．03024～0．1512mg／ml范围内,芬布芬峰面积与质量浓度呈良好的线性关系。线性方程为y=2．5272E-08x—1．7078E-03,线性相关系数r=-0．9999,回收率为99．2％和99．6％,重复性实验RSD=0．18％、RSD=0．23％（n=5）。结论：方法简便,快速,准确,适用于该产品质量控制。