Edmund Kozlowski

Evaluation of the suitability of selected porous polymers for preconcentrations of volatile organic compounds

Abstract Breakthrough volumes on six porous polymers (Chromosorb 101, 103, 107 and Porapak N, Q, T) have been determined for vapours of 25 volatile organic compounds (amines, chlorinated hydrocarbons, etc.). The volumes were determined by a direct method, which seems to be simpler compared to the indirect estimation of breakthrough volume on the basis of such chromatographic parameters as retention volume, number of theoretical plates and peak width. The effect of the concentration of a model compound (acetone) in the gas mixtures on breakthrough volume was also determined on all investigated sorbents. The invetigations were carried out in a specially designed apparatus employing the method of diffusion tubes for the generation of model gaseous mixtures.

Passive dosimeters — an approach to atmospheric pollutants analysis

Abstract The paper presents a review of the passive methods of sampling of inorganic and organic atmospheric pollutants. The importance of these methods, enabling both evaluation of workplace personal exposure and area monitoring, has been discussed. Commercially available personal monitors, as well as devices under further laboratory investigation have been described. Fundamental theoretical equations describing the operation of both passive devices based on diffusion through an air gap to a layer of collective media and passive devices with permeable membranes have been put forward. Presented and discussed herein are papers dealing with the investigation of the applicability of these devices under laboratory and field conditions, as well as with the comparison of passive monitors with active devices (e.g., detector tubes).

Theoretical principles of thin layer headspace analysis

Theoretical principles of thin layer headspace (TLHS) analysis are reviewed. TLHS utilizes a special heated column in which a continuously flowing thin film of a liquid sample is contacted with a continuously flowing pure gas. Volatile analytes contained in the liquid sample pass to the gas phase and are carried away from the column. For the determination of volatile organic halogen (VOX), the analytes in the gas are mineralized at 900°C, and the mineralization products (hydrogen halides) are absorbed in an appropriate solvent in a second TLHS column kept at ambient or sub‐ambient temperature. The mineralization products can be quantified in the liquid sorbent using conductometric, spectrophotometric, as well as direct and indirect potentiometric methods. The unique feature of this method is the dynamic preconcentration of the analyte in the liquid sorbent. When analyte speciation is required, the liquid sorbent can be generated in TLHS column II by condensation of the water vapour carried by the gas from...

Continuous flow thin layer headspace (TLHS) analysis

SummaryThe theoretical basis of the optimization of the TLHS analysis has been further developed. A critical value of the enrichment factor (Fcr, inf) has been defined as the value, at which the relative systematic error and the relative precision error are equal. These errors have been defined with respect to the maximum and the inflexion point of the recovery curve of the volatile analyte in the liquid sorbent. Two methods of volatile organic halogen (VOX) determination in tap water, viz. the conductometric and the indirect potentiometric method, have been compared (with respect to their analytical characteristics) using natural samples. The accuracy of both methods proved to be similar, yet the conductometric method was more precise. The variances of the methods occurred to be homogeneous in the particular measuring series independently of the long time intervals between the particular measuring series and the differentiated VOX levels.

Identification and Determination of Organohalogen Compounds in Swimming Pool Water

Abstract Volatile organohalogen compounds were determined in a swimming pool using three methods: determination of volatile organic halogen (VOX) after sorption on XAD-4 solid sorbent, thermal desorption and coulometric titration of the halides formed; identification and determination of the individual organohalogen compounds after sorption on XAD-4, solvent extraction and chromatographic determination; direct injection of aqueous samples to the chromatographic column. The concentration of organohalogen compounds varied from 35.9 to 99.7 μg/dm3 for trichloromethane, 22.0 to 57.7 μg/dm3 for dichloromethane, 2.4 to 27.4 μg/dm3 for trichloroethylene, 2.3 to 14.7 μg/dm3 for bromodichloromethane and 4.2 to 7.6 μg/dm3 for tetrachloromethane. The results obtained by the three methods are consistent in principle.

Comparative study of breakthrough volumes BTV on various sorbents

ZusammenfassungAn 10 verschiedenen Sorbentien (Chromosorb 102, 104, 105, 106; Porapak R und S; XAD-2; XAD-7; Tenax GC; Carbosphere) wurden für 15 flüchtige organische Verbindungen (halogenierte Kohlenwasserstoffe, Alkohole u. a.) die Durchbruchsvolumina bestimmt. Es wurde dafür ein indirektes Verfahren mit typischen chromatographischen Parametern (Retentionsvolumen, Peakbreite) benutzt. Die Methode erscheint nützlich für die vorläufige Abschätzung der Adsorptionskapazität von Sorbentien, eignet sich jedoch nicht für die Untersuchung des Einflusses verschiedener Parameter auf das Durchbruchsvolumen.SummaryBreakthrough volumes on ten sorbents (Chromosorb 102, 104, 105 and 106, Porapak R and S, XAD-2, XAD-7, Tenax GC and Carbosphere) have been determined for vapours of 15 volatile organic compounds (halogenated hydrocarbons, alcohols, etc.). The volumes were determined by an indirect method employing typical chromatographic parameters such as retention volume and peak width.The method seems to be useful for preliminary estimation of adsorption capacity of various sorbents. It is not suitable, however, for the investigation of the effect of various parameters on the breakthrough volume.

Determination of Volatile Halogenated Compounds in Tap and Surface Waters from the Gdańsk District

Abstract The present method is based on preconcentration of organic contaminants on XAD-4 as sorbent, thermal desorption, mineralization and coulometric argentometric titration for the final determination of halides. The results were calculated as the total parameter VOX (volatile organic halogen) expressed as chlorine. The method has been used for the VOX determination in tap water, Vistula river water and Baltic Sea water. Sampling of the Baltic Sea water has been carried out during the research cruise of the r/v ‘Oceania’. The relatively high anthropogenic pollution of the river Vistula (c vox = 11–45 μg Cl/cd3), Gulf of Gdansk (c vox = 0.6–4.5 μg Cl/dm3) and the Pomerania Bay (c vox = 2 μg Cl/dm3) has been determined. The VOX concentration in the tap water varied between 13 and 56 μg/dm3; that is, this water is seriously polluted by volatile organic halogen compounds.

Schnellbestimmung von C, H und S mit Hilfe der Entflammungsmineralisation

ZusammenfassungÜber eine neue Methode zur Simultanbestimmung von C, H und S wurde berichtet. Durch Kombination der Entflammungsmineralisation im Senkrechtrohr und der gravimetrischen Endbestimmung bei Verwendung eines Wägeautomaten gelang die Entwicklung einer schnellen, sehr einfachen und ausreichend genauen Methode. Der hohe Linearitätsbereich des Endbestimmungsverfahrens ermöglicht den Einsatz der gleichen Apparatur sowohl im Mikro- als auch im Halbmikromaßstab.SummaryA new method for simultaneous determination of C, H and S was reported. By combination of flash mineralization in the vertical combustion tube and gravimetric determination of the end point using an automatic balance, it was possible to develop a rapid, very simple and sufficiently accurate method. The large linearity range of the method for determining the end point enables the same apparatus to be used both on the micro and on the semimicro scale.

Determination of total carbon and total organic carbon from volatile air pollutants: V. — Determination of TC and TOC in laboratory air

SummaryDetermination of TC and TOC in laboratory air by means of the method described in previous papers was undertaken. The results were evaluated statistically and were found free from constant and proportional systematic error. Additionally, the accuracy of the method was evaluated for low carbon levels. From the apparatus blank determined under these conditions the detection limit of the method is found to beca. 1 ppm of carbon. The method developed can be utilized in practice for control of the degree of air pollution by volatile organic compounds.ZusammenfassungDie beschriebenen Methoden wurden zur Bestimmung des TC- und TOC-Gehaltes in Laboratoriumsluft erprobt. Auf Grund statistischer Auswertung der Analysenergebnisse ergibt sich, daß die Resultate der TC- und TOC-Bestimmung mit keinem konstanten und proportionellen systematischen Fehler belastet sind. Die Genauigkeit des entwickelten Verfahrens wurde für niedrige Kohlenstoffgehalte zusätzlich geprüft. Die Erfassungsgrenze kann nach Berücksichtigung des Apparaturblindwertes unter den angegebenen Bedingungen auf etwa 1 ppm Kohlenstoff geschätzt werden. Das Verfahren kann somit zur Beurteilung der Luftverunreinigung durch

Determination of total carbon and total organic carbon from volatile air pollutants. Part III: Selective oxidation of volatile organic compounds in the presence of methane

SummaryThe possibility of selective oxidation of volatile organic compounds in the presence of methane was investigated. Thermal decomposition of a mixture of CH3COONa and NaOH was used as the source of methane introduced into a stream of purified air. Oxidation of the methane present in a stream of air on a layer of the Körbl catalyst is only slight and does not exceed 10%, even in the case of simultaneous presence of acetic acid, which is completely oxidized under identical conditions. Other volatile organic compounds also undergo complete oxidation. It was found that the degree of oxidation of 16 organic compounds is ≥97.5%. The detection limit of the developed method depends primarily on the effective removal of the so-called “carbon background” of the air sample, resulting from the presence of CO2, CO and CH4. The developed method of selective oxidation can be used for specific elimination of the effect of methane on the results of determinations of TOC in volatile air pollutants.ZusammenfassungDie Möglichkeit einer selektiven Oxydation flüchtiger organischer Verbindungen neben Methan wurde untersucht. Methan wurde im gereinigten Luftstrom durch thermische Zersetzung eines Gemisches von CH3COONa und NaOH hergestellt. Die Oxydation des Methans im Luftstrom an einer Körbl-Katalysatorschicht ist gering und überschreitet nicht 10%, sogar bei gleichzeitiger Anwesenheit von Essigsäure, welche unter diesen Bedingungen — wie andere flüchtige, organische Verbindungen — vollständig oxydiert wird. An 16 organischen Verbindungen wurde festgestellt, daß der Oxydationsgrad≧97,5% beträgt. Die Erfassungsgrenze der entwickelten Methode zur TOC-Bestimmung ist vor allem von einer effektiven Beseitigung des sogenannten Kohlenstoffblindwertes abhängig, der durch Anwesenheit von CO2, CO und CH4 in der Luftprobe verursacht wird. Das entwickelte, selektive Oxydationsverfahren kann somit zur spezifischen Eliminierung des Einflusses von Methan auf die Bestimmungsresultate des TOC-Gehaltes aus flüchtigen Luftverunreinigungen Anwendung finden.