Determination of diborane by adsorption sampling using modified silica gel and the chromotropic acid-HPLC method.

A method for determining atmospheric diborane in concentrations higher than 1/10 of TLV, i.e., 0.01 ppm, has been developed using the adsorption sampling method. Silica gel impregnated with potassium permanganate, synthetic resin activated carbon impregnated with or without mercury(II) chloride and activated carbon impregnated with chromate salt showed adsorption capacities larger than 18 l of 3 ppm diborane test gas when the test gas was drawn at 300 ml/min. Complete desorption of the adsorbed diborane was possible only from silica gel impregnated with potassium permanganate into a hydroxylamine hydrochloride solution. As methods for determining the desorbed boron, both the chromotropic acid-HPLC method and ICP-AES were applied. The former was more sensitive, but the latter was less influenced by coexistent substances. The most sensitive and reproducible procedure for diborane determination was as follows: diborane is collected with silica gel impregnated with potassium permanganate (0.05% (w/w)) and desorbed into hydroxylamine hydrochloride solution (400 micrograms/ml) followed by the determination of boron by the chromotropic acid-HPLC method. When diborane in 3 l of 0.1 ppm test gas was collected, the desorption efficiency was 105.3% with an RSD of 13.5%. The limit of quantitation of this method was 0.0026 ppm in 3 l air. Much lower concentrations can be determined by sampling larger amounts of air.     

硅胶管吸附采样-毛细管气相色谱法同时测定空气中6种酚类化合物

目的 建立空气中6种酚类化合物硅胶管吸附采样-毛细管柱气相色谱同时测定的方法.方法 空气中酚类化合物经硅胶管吸附采集,用乙醇解吸后经HP-5石英毛细管柱(30.00 m×0.32 mm×0.25 μm)分离,火焰离子化检测器(FID)检测.结果 本法采样效率为95.3％～100.0％;解吸效率为78.6％～92.5％;加标回收率为89.2％～114.0％;方法精密度为2.6％～9.8％;检测限0.81～1.00 mg/L.结论 该法简便易行、灵敏准确、抗干扰能力强,适用于空气中多种酚类化合物的测定.     

硅胶采样管采集测定空气中丙烯酰胺的方法学研究

处理后的微球硅胶制成采样管，以０．３Ｌ／ｍｉｎ于现场采样３０ｍｉｎ，密封。分析时，用蒸馏水解吸硅胶上的丙烯酰胺，用紫外照射使之溴化，经乙酸乙酯提取后，用气相色谱电子捕获检测器检测。此法线性范围为０～１０．０ｍｇ／Ｌ，最低检测限为０．０１ｍｇ／Ｌ，线性良好，Ｔ＞０．９９９。批内、间精密度均良好，变异系数分别为３．５％～６．９７％和１．２６％～５．３４％，解吸效率≥９６％，２５０ｍｇ硅胶填充的采样管，其穿透容量＞０．０５ｍｇ，采集的样品至少可稳定１５天。当丙烯酰胺浓度为１．８６ｍｇ／ｍ３时，硅胶管采样效率仍为１００．０％，充分满足了现场需要。此法应用于山东四个化工厂，并同时同地用冲击式吸收管进行采样测定，结果经ｔ检验，表明两种方法无明显差异（Ｐ＞０．５００）。此改进后方法准确、方便，并可用于个体采样。     

Laboratory evaluation of silica gel sorbent tubes for sampling hydrogen fluoride

The NIOSH sampling and analytical method for inorganic acids employs a silica gel sorbent tube for the collection of five common inorganic acids with simultaneous determination of these acids in a single sample by ion chromatography. When the method was extended to the determination of hydrogen fluoride (HF) the sampled HF reacted with the silica gel and glass fiber of the sampler, but the reaction products remained trapped on the sorbent. Silica gel samplers were evaluated for the collection of HF from laboratory generated atmospheres. Factors tested included capacity, storage stability, humidity, accuracy and precision. Based on comparison with impinger collection, the mean recovery of HF from silica gel tube samples was 100.7% with a precision of 0.144.     

HPLC法与香草醛比色法测定保健品中的人参皂甙

〔目的〕应用高效液相色谱法和分光光度法分别同时检测保健食品中人参总皂甙的含量。〔方法〕高效液相色谱法采用短色谱柱 ,低乙晴体积分数 ,非线性梯度洗脱对 6种主要人参皂甙Rg1,Rb1,Re,Rb2 、Rc、Rd进行分析。〔结果〕方法回收率 95 .6 %～ 97.7% ,检出限 2 .2ng ,RSD =1.30 %～ 6 .90 %。分光光度法用大孔吸附树脂吸附人参总皂甙 ,经梯度洗脱处理 ,香草醛显色后测定人参总皂甙含量。方法回收率 :95 .6 %～ 10 7.4 % ,检出限 :1.2 5 μg,RSD =3.5 1%～ 4 .17%。两种方法测定人参总皂甙结果有显著性差异 (t=4 .5 1>t( 0 .0 5) =1.895 )。〔结论〕HPLC法适用于单个皂甙的测定 ,比色法适用于总皂甙含量的测定     

火焰光度气相色谱法测定空气中磷化氢的规范化研究

空气中磷化氢采集在内衬铝箔的复合膜袋中，取１ｍｌ注入气相色谱仪，经ＧＤＸ－１０１柱分离后，火焰光度检测器检测。样品浓度为０．２～１０．６ｍｇ／ｍ３时，测定的ＲＳＤ为４．０％～９．１％。样品在铝箔袋中保存，浓度可保持一周不变。本方法经辽宁省劳动卫生研究所验证，结果基本一致。     

比色法测定木莓根中三萜类成分的含量

目的建立木莓根中三萜成分含量的测定方法。方法以熊果酸为对照品,以5％香草醛-冰醋酸溶液、高氯酸为显色系统,采用紫外分光光度法在550nm波长处测定样品吸光度。结果方法的线性范围为0.042～0.132mg/ml,标准曲线：A=1．5705C＋0.6002,R=0.9997（n=5）,平均回收率为98．34％,原药材中三萜成分含量为1．87％。结论此方法简便、快速,结果准确、可靠,适于木莓根中的三萜成分的质量控制。     

The structure of HBsAg particles is not modified upon their adsorption on aluminium hydroxide gel

Current Hepatitis B vaccines are based on recombinant Hepatitis B surface antigen (HBsAg) virus-like particles adsorbed on aluminium (Al) gel. These particles exhibit a lipoprotein-like structure with about 70 protein S molecules in association with various types of lipids. To determine whether the adsorption on Al gel affects HBsAg structure, we investigated the effect of adsorption and mild desorption processes on the protein and lipid parts of the particles, using various techniques. Electron microscopy showed that the size and morphology of native and desorbed HBsAg particles were comparable. Moreover, infrared and Raman spectroscopy revealed that the secondary structure of the S proteins was not affected by the adsorption/desorption process. Affinity measurements with Surface Plasmon Resonance showed no difference between native and desorbed HBsAg for HBsAg-specific RF-1 monoclonal antibody. Steady-state and time-resolved fluorescence data of the intrinsic fluorescence of the S proteins further indicated that the adsorption/desorption of HBsAg particles on Al gel did not modify the environment of the most emitting Trp residues, confirming that the conformation of the S proteins remains intact. Moreover, using environment-sensitive 3-hydroxyflavone probes, no significant changes of the lipid core and lipid membrane surface of the HBsAg particles were observed during the adsorption/desorption process. Finally, the ratio between lipids and proteins in the particles was found to be similar before and after the adsorption/desorption process. Taken together, our data show that adsorption on Al gel does not affect the structure of the HBsAg particles.     

工作场所空气中磷化氢的离子色谱测定法

目的 建立工作场所空气中磷化氢的离子色谱测定法.方法 空气中磷化氢用酸性高锰酸钾溶液采集,盐酸羟胺还原后,经阴离子色谱柱分离,电导检测器检测,保留时间定性,外标法定量.结果 磷化氢在0.035～1.753 μg/ml范围内线性关系良好,相关系数r=0.9997,检出限为0.011 μg/ml,最低检出浓度为0.007 ...     

A mathematical model for Rn sampling by activated C adsorption

This paper describes a diffusion/adsorption model that has been developed for the transport of Rn in an activated carbon porous bed. It is useful in studying the carbon canister Rn sampling technique used for monitoring Rn levels in air. The model calculates the amount of Rn adsorbed by the canister for various situations. The predictions of the response of the canister to both constant, as well as a periodic varying concentration of Rn in the surroundings, compares very well with experimental data. Based on this model, it is possible to simulate on a computer the response of the canister for an arbitrarily varying surrounding Rn level. Such computer simulations are effective tools in the design of a more accurate carbon canister monitor.