气相色谱-质谱法测定工作场所空气中碘甲烷

建立了测定工作场所空气中碘甲烷的气相色谱–质谱方法。空气中的碘甲烷用多孔玻板吸收管采集,经DB–1型(50 m×0.32 mm,0.52μm)毛细管柱分离后,用气相色谱–质谱方法进行定性、定量。碘甲烷溶液的质量浓度在0.0085-15.2μg/mL范围内与色谱峰面积线性关系良好,相关系数为0.9996,检出限为0.0025μg/mL,定量限为0.0085μg/mL,最低检出限浓度为0.0033 mg/m^(3)。方法的批内精密度为1.5%-3.2%(n=6),批间精密度为2.4%-7.1%(n=6),样品加标回收率为99.6%-102.9%。该方法同时进行定性、定量,适用于工作场所空气中碘甲烷的测定。     

热脱附/冷阱捕集–气相色谱法同时测定空气中多种挥发性有机物

使用Tanax-TA管富集样品,建立热脱附/冷阱捕集–气相色谱法同时测定工作场所空气中苯系物、丙酮、丁酮、乙酸乙酯、乙酸丁酯等12种常见挥发性有机物分析方法。该法线性范围为5~100μg/m L,相关系数不小于0.999 0。12种挥发性有机物的检出限为3.0×10~(–4)~1.7×10~(–3) mg/m~3(以采样体积为1 L计),加标回收率为80.9%~106.5%,测定结果的相对标准偏差为2.08%~4.09%(n=10)。该法样品处理简单,可应用于工作场所空气中挥发性有机物的快速测定。     

气相色谱–质谱法测定地表水中硝基苯

建立吹扫捕集–气相色谱–质谱联用法测定地表水中硝基苯的方法。用吹扫捕集法对水样进行前处理,以HP–5弱极性毛细管柱(30 m×0.32 mm,0.25μm)进行分离,质谱法测定水中硝基苯的含量。硝基苯的质量浓度在0.00~60.0μg/L范围内与色谱峰面积线性关系良好,线性相关系数为0.999 4,方法的检出限为0.03μg/L。测定结果的相对标准偏差小于2%(n=7),地表水样品加标回收率在91.2%~96.5%之间。该方法操作简便,检出限低,精密度和准确度高,适用于地表水中硝基苯的测定。     

顶空气相色谱-质谱法测定废水中挥发性有机化合物和卤化溶剂

建立顶空气相色谱–质谱法测定废水中挥发性有机化合物和卤化溶剂的含量。样品采用DB–624色谱柱净化,以顶空方式进样,用气相色谱–质谱法对挥发性有机化合物和卤化溶剂进行测定,外标法定量。挥发性有机化合物和卤化溶剂的含量在0.01～2.0μg范围内与峰面积呈良好的线性关系,相关系数均大于0.998,方法检出限为0.1μg/L。测定结果的相对标准偏差为1.30%～2.22%(n=6),样品加标回收率为85.3%～106.4%。该方法简单、快速,结果准确、可靠,适用于废水中挥发性有机化合物和卤化溶剂的测定。     

气相色谱–质谱联用法测定空气中的丙烯腈

建立测定空气中丙烯腈的气相色谱–质谱联用方法。用活性炭管采集样品,以体积分数为2%的丙酮二硫化碳溶液解吸,利用气相色谱–质谱法以选择离子扫描方式采集数据并进行分析,以色谱峰面积外标法定量。丙烯腈的质量浓度在0~100μg/m L范围内与色谱峰面积线性关系良好,线性相关系数(r~2)为0.999 0。丙烯腈检出限为1.2μg/m L,最低检出质量浓度为0.16 mg/m~3(以采样体积7.5 L计),平均加标回收率为97.0%~99.3%,测定结果的相对标准偏差为3.0%~4.2%(n=6)。该方法定性、定量准确,精密度、灵敏度高,可用于空气中丙烯腈的常规检测。     

顶空/气相色谱-质谱法同时测定报纸中14种溶剂残留

建立了同时测定报纸中14种溶剂残留量的顶空/气相色谱-质谱分析法。采用顶空气相色谱技术,以毛细管柱(Agilent HP-INNOWAX,60 m×250μm,0.25μm)分离,选择离子监测模式(SIM)下进行质谱检测。在优化的顶空/气相色谱-质谱分析条件下,14种溶剂残留在2~20μg范围内线性关系良好,相关系数均不小于0.995;方法的定量下限(S/N=10)均小于0.01 mg/m2。加标水平为3.97~16.28μg时,待测物的平均回收率为86.6%~101.8%,相对标准偏差(RSD,n=6)均不高于6.8%。本方法快速、准确、灵敏,适用于报纸中溶剂残留的测定。     

液液萃取–气相色谱法测定地表水中硝基氯苯

建立气相色谱法同时测定地表水中3种硝基氯苯同分异构体的方法。用液液萃取法萃取地表水样品中的硝基氯苯,并对影响萃取效率的因素进行了优化。采用甲苯作为萃取溶剂,以DB–1701毛细管色谱柱(30 m×0.32mm,0.25μm)进行分离,气相色谱法检测地表水中硝基氯苯的含量。硝基氯苯的质量浓度在0.00~40.0μg/L范围内与其色谱峰面积呈良好的线性关系,线性相关系数均大于0.995,检出限为0.07~0.08μg/L,低于《地表水环境质量标准》限值。加标回收率为85.3%~98.0%,测定结果的相对标准偏差均小于2%(n=6)。该方法操作简单,重现性好,准确度好,检测速度快,适用于地表水中硝基氯苯的测定。     

高效毛细管柱气相色谱法快速测定樟脑丸中萘

应用并试验了高效毛细管柱气相色谱法分离和测定樟脑丸中萘含量。选择二硫化碳作为试样溶剂,因它具有溶样速度快和提供良好的色谱分离的介质条件。色谱分析中采用了DB-17毛细管柱(30 m×0.25 mm,0.25μm)和FID检测器,方法的检出限为5×10-4μg,RSD在0.92%~3.37%之间;加标回收率为96.2%~104.8%,回归方程的相关系数为0.999 9(进样量为1μL)。     

GC–MS–MS法测定洗发水和沐浴露中二噁烷

建立GC–MS–MS测定洗发水和沐浴露中二噁烷的方法。向样品中加入适量氯化钠并配制成水溶液,气相色谱柱为HP–5毛细管柱(30 m×0.25 mm,0.25μm),以氦气为载气,程序升温,顶空进样,以母离子m/z 88和二级质谱子离子m/z 57,58为定性离子,m/z 57为定量离子。二噁烷的质量浓度在0.10~10.0μg/m L范围内与m/z 57离子的色谱峰面积呈良好的线性关系,相关系数r=0.999 7,方法的检出限为0.05 mg/kg。测定结果的相对标准偏差为3.6%(n=6),样品加标回收率80.6%~107.0%。该方法专属、灵敏、操作简便,可用于洗发水、沐浴露中二噁烷的测定。     

气相色谱–质谱法测定纤维板和刨花板中邻苯二甲酸酯类增塑剂

建立气相色谱–质谱方法测定纤维板和刨花板中6种邻苯二甲酸酯的方法。样品用正己烷提取后,采用HP–5MS毛细管柱(30 m×0.25 mm,0.25μm)分离,以内标法进行定量。邻苯二甲酸酯BBP,DBP,DEHP,DNOP在0.2~2μg/m L范围内线性均良好,检出限为2 mg/kg;DINP,DIDP在2.0~20μg/m L范围内线性均良好,检出限为10 mg/kg。线性相关系数均大于0.999。样品加标回收率为86.00%~95.17%,测定结果的相对标准偏差为3.06%~9.72%(n=6)。该方法具有较高的灵敏度,可应用于各类纤维板和刨花板产品中邻苯二甲酸酯类增塑剂的检测。     

HEPT类化合物的QSAR研究

为定量结构／活性相关性研究提取了量子化学参数,拓扑指数Am,分子连接性指数^mxt及疏水性常数,同时应用正交变换和最佳变量子集算法（Leaps-and-Bonds)进行了变量压缩和选择,进而实施了多元回归分析,并由此结果进行了HEPT类化合物（1－[(2-hydroxyethoxy)methyl]-6-(phenylthio)-thymine derivatives)的结构／活性关系的理论解释,进行了人工神经网络法对于该类化合物的活性预测,其结构明显好于多元回归法。     

Effect of the pH of the medium on the chemical shifts in the PMR spectra and on the distribution of the π-electron density

The dependence of the chemical shifts of the ring protons on the pH of the medium for a number of 4-hydroxyquinoline derivatives was studied by means of PMR spectroscopy. The dipolar and uncharged hydroxy forms exist in equilibrium in aqueous solutions. The effect of intramolecular hydrogen bonding on the character of the dependence of the chemical shift on the pH of the medium in the case of 3-piperidinomethyl-4-hydroxyisoquinoline was investigated. The possibility of the separate protonation of the ring nitrogen and the side-chain nitrogen in 3-piperidinomethyl-4-hydroxyisoquinoline was established. The distribution of the -electron density in 4-hydroxyisoquinoline is in good agreement with its chemical behavior.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1546–1549, November, 1971     

Effect of the pH of the medium on the chemical shifts in the PMR spectra and on the distribution of the π-electron density

The dependence of the chemical shift of the ring protons on the pH of the medium for a number of 3-hydroxyquinoline derivatives was studied by PMR spectroscopy. The regions of ionization of the molecules, which correspond to the ranges of acidic, neutral, and alkaline media, were found. In D₂O, 3-hydroxyquinoline is present only in the uncharged hydroxy form. The presence of intramolecular hydrogen bonding in 4-dimethylaminomethyl-3-hydroxyquinoline has a substantial effect on the character of the dependence of the chemical shift on the pH of the medium; the existence of separate protonation of the nitrogen atoms of the ring and the side chain of 4-dimethylaminomethyl-3-hydroxyquinoline was established. The distribution of the -electron density in the 3-hydroxyquinoline molecule is in good agreement with its chemical behavior during electrophilic substitution.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1540–1545, November, 1971.     

From the Micro- to the Macro-: Managing the Conservation of the Warship,Vasa

Sweden's famous warship, Vasa, sank on her maiden voyage in August 1628, and remained on the bottom of Stockholm harbour for 333 years. Raised in 1961, she became the first large-scale wooden object to be treated with polyethylene glycol (PEG). In the summer of 2000 a number of acidic salt precipitations were noticed on the surface of the ship and on wooden artefacts in the storerooms. An international research project has been established to look into the causes of this problem and suggest possible re-treatments. Meanwhile projects are underway to monitor movements in the ship, to build a better support system, and to replace the thousands of iron bolts holding the structure together, while a sophisticated new climate system has recently been installed in the museum.