Flow system to gas capture from a nebulized solution

The use of aerosol produced in a nebulization chamber is proposed as an alternative to gas sample capture in flow systems. This paper describes the coupling of a sampling interface with a flow system, for in situ gas monitoring. Aspects related with the behavior of aerosol formation and gas solubilization in liquid drops are discussed. The method is applied to the determination of residual lime in acidic soils. Aliquots of 5.0 ml of 1.0 mol l⁻¹ HCl were mixed with soil samples (1 g). The CO₂ released from these samples was captured by a nebulized aerosol and determined conductivity. The analytical curve from 1.0×10⁻² to 5.0×10⁻² mol kg⁻¹ CaCO₃ was ploted applying the matrix matching approach. This proposition, allowed an increase in the sensibility with detection limit of 6.0×10⁻³ mol kg⁻¹. The precision was good (R.S.D. <3%) for an analytical frequency of 22 determinations per hour. A fair agreement, at 95% confidence level, was found between the results from the proposed method and certified values of the investigated samples.     

Spectrophotometric Determination of Ipratropium Bromide in Liquid for Nebulization

ABSTRACT

Three simple and sensitive spectrophotometric methods for the determination of ipratropium bromide (IPB) in liquid for nebulization are described. Method A, is based on the formation of a charge transfer complex with iodine. The reaction product is measured spectrophotometrically at 278 nm. Method B, is based oh the formation of an ion – association complex between the drug and an acidic dye, Bromocresol green (BCG), which is extractable into chloroform and has an absorption maximum at 418 nm. Method C, uses derivative spectrophotometry for the determination of IPB by measuring the D₂-value at 232 nm. Beer's law is obeyed over the concentration range 1-10, 2-16 and 5-30 μg ml^? for method A, B and C, respectively. The optimum conditions for the formation of the charge transfer or ion-association complexes were optimized. The proposed methods were applied for the determination of IPB in liquid for nebulization. Evaporation to dryness and extraction of the residue with isopropanol, were performed before application of methods A & B. Mean percentage recoveries were found to be 99.67 ± 0.79, 99.26 ± 1.06 and 100.21 ± 0.85 for method A, B, and C, respectively.     

气动雾化进样-微波等离子体炬全谱仪测定矿泉水中的Na,Mg, Ca,Li, Sr

采用微波等离子体炬(MPT)作为激发光源,通过气动雾化系统进样,循环水冷凝-浓硫酸吸水装置作为去溶系统,以Ar为等离子体工作气体,建立了氩微波等离子体炬全谱仪检测矿泉水中Na, Mg, Ca, Li和Sr等五种元素的方法。详细探究了微波功率源功率、工作气流量及载气流量等实验参数对待测元素发射信号的影响,并且对这些参数进行了优化。在优化的实验条件下,对11种瓶装饮用矿泉水进行了检测,方法对Na, Mg, Ca, Li和Sr的检出限分别为4.4,21,56,11和84 μg·mL-1,相对标准偏差范围为1.30%～5.45%(n=6),加标回收率在84.6%～98.5% 之间。实验结果表明,此装置简单便捷、分析成本低;此方法分析速度快、精确度与准确度高、能够同时测定多种元素,适用于矿泉水中元素检测,为打击非法商家提供了手段,同时也为人们的饮用水质量提供了安全保障,有望用于食品安全、药品安全、临床诊断及更多领域的分析检测。     

用Monte Carlo模拟方法研究ICP－AES中的物理化学过程──Ⅰ．雾化过程的模拟

本文讨论了用ＭｏｎｔｅＣａｒｌｏ方法模拟ＩＣＰ－ＡＥＳ中雾化过程的理论依据和基本思想，得到的雾化效率与实验结果比较吻合。     

原子光谱分析中的浆液雾化进样

提出了ICP-AES／MS方法中浆液雾化进样问题。叙述了均匀与稳定的浆样制备方法,包括使用添加剂和pH调节。讨论了颗粒大小分布、zeta电位测定等浆样稳定性的表征方法。评述了校准曲线法、标准加入法和本征内标法等校准方法。     

正丁醇对电感耦合等离子体发射光谱的增敏作用

研究了ICP光源中正丁醇对水样品溶液物理性质(表面张力、粘度)及雾化特性的影响,观测了元素Fe、Si、V和Sr的发射强度和信背比,并且用ICP发射光谱法测定了自来水中痕量元素Pb和Cd.结果表明,有机溶剂正丁醇能够改变试液物理性质,提高雾化效率,增强光源辐射强度;元素Pb和Cd的RSD分别为5.84%和7.41%,回收率分别为94.3%和92.7%.     

磁化溶液样品对ICP发射光谱的增敏效应

利用磁感应强度为0.24T的磁场处理含乙醇的水溶液,研究了样品溶液的物理性质和雾化特性以及样品溶液中元素的谱线强度随磁化时间的变化情况,并且讨论了磁化机理。实验结果表明,随着磁处理时间的延长,分析样品的有效利用率提高了;当样品中加入乙醇时,元素的谱线强度较早地出现了峰值。在磁化时间为2 h的条件下,不含乙醇的样品溶液中,元素Zn, Pb, Cd, Fe, Si, Cu, Cr和Sr的谱线强度比溶液未磁化时分别提高了22.9%, 38.8%, 25.6%, 48.3%, 52.4%, 6.0%, 22.3%和22.7%;含6%乙醇的样品溶液中,元素Zn, Pb, Cd, Fe, Si, Cu, Cr和Sr的谱线强度比溶液未磁化时分别增加了22.4%, 42.6%, 39.4%, 43.9%, 72.4%, 9.7%, 16.1%和17.1%。样品溶液磁化后进行分析, 有利于降低光谱分析检出限。     

Enhancement of filtration efficiency by electrical charges on nebulized particles

There have been few investigations of effects of electrical charge, carried by lab-generated particles, on filtration efficiency testing. Here, we measured the elementary charge on particles and the fraction of particles carrying that charge with a combined electrometer, differential mobility analyzer, and scanning mobility particle sizer. A typical solid NaCl aerosol and liquid diethylhexyl sebacate (DEHS) aerosol were generated with Collison and Laskin nebulizers, respectively. Our experimental results showed that NaCl aerosols carried more charge after aerosol generation. The average net elementary charge per particle was approximately 0.07. The NaCl aerosol was overall positively charged but contained a mixture of neutral and charged particles. Individual particles could carry at most four elementary charges. According to constant theorem, we speculated that original NaCl aerosol contained 17% neutral, 45% positive-, and 38% negative-charged particles in the diameter range from 30 to 300 nm. A Kr-85 neutralizer was used to decrease the charge on the NaCl particles. Our results indicated that the DEHS aerosol was electrically neutral. The effects of electric charge on particle collection by electret and electroneutral high efficiency particulate air (HEPA) filters were analyzed. Theoretical calculations suggested that charges on original NaCl aerosol particles enhanced the filtration efficiency of HEPA filters.     

悬浮液技术-火焰原子吸收光谱法测定明胶中钙镁

用悬浮液技术处理明胶样品。将样品烘干、粉碎、过筛,制备成琼脂悬浮液。取适量样品悬浮液加入释放剂Sr2+配制成试剂,喷入空气-乙炔火焰进行测定,建立了悬浮液技术-火焰原子吸收光谱法快速测定明胶中钙、镁的分析方法。以空白溶液为参比,用工作曲线法测定。对琼脂溶液用量、化学干扰、试液与空白溶液粘度一致性、背景吸收干扰及检出限进行了考察。测定结果与灰化法一致,相对误差小于±0．9％,相对标准偏差小于5．2％。方法简便、准确。