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The combined application of impinger system and permeation tube for the generation of volatile organic compound standard gas mixtures at varying diluent flow rates.

Kim KH, Susaya J, Cho J, Parker D - Sensors (Basel) (2012)

Bottom Line: The performance of the impinger standard gas generation system was assessed for four aromatic VOCs (benzene, toluene, ethylbenzene, and m-xylene; BTEX) at varying flow rates (FR) of 50 to 800 mL·min(-1).Experimental results corrected by such a formula indicate that the compatibility between the APR and MPR generally increased with low FR, while the reproducibility was generally reduced with decreasing flow rate.Although compatibility between different PRs is at a relatively small and narrow FR range, the use of correction formula is recommendable for the accurate use of PT.

View Article: PubMed Central - PubMed

Affiliation: Department of Environment & Energy, Sejong University, Seoul 143-747, Korea. khkim@sejong.ac.kr

ABSTRACT
Commercial standard gas generators are often complex and expensive devices. The objective of this research was to assess the performance of a simplified glass impinger system for standard gas generation from a permeation tube (PT) device. The performance of the impinger standard gas generation system was assessed for four aromatic VOCs (benzene, toluene, ethylbenzene, and m-xylene; BTEX) at varying flow rates (FR) of 50 to 800 mL·min(-1). Because actual permeation rate (APR) values deviated from those computed by the manufacturer's formula (MPR), new empirical relationships were developed to derive the predicted PR (PPR) of the target components. Experimental results corrected by such a formula indicate that the compatibility between the APR and MPR generally increased with low FR, while the reproducibility was generally reduced with decreasing flow rate. Although compatibility between different PRs is at a relatively small and narrow FR range, the use of correction formula is recommendable for the accurate use of PT.

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Illustration of (a) the sampling device for generating gaseous BTEX standards using an impinger system and (b) the secondary sampling system for transferring BTEX samples from the Tedlar bag into the sorbent tube for GC-FID determination. Number labels: (1) Pure N2 tank; (2) N2 flow regulator; (3) Impinger bottle and cap with inlet (left side) and outlet (right side) ports (750 mL); (4) Glass tubing with a bubbler tip to evenly distribute the diluent gas; (5) Aluminum container; (6) Water heated to 25 °C; (7) Heater; (8) Temperature sensor; (9) Temperature regulator; (10) Permeation tube device for BTEX; (11) Empty 10 L Tedlar bag; (12) Tedlar bag containing BTEX; (13) Sorbent tube; and (14) Sibata vacuum pump.
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f1-sensors-12-10964: Illustration of (a) the sampling device for generating gaseous BTEX standards using an impinger system and (b) the secondary sampling system for transferring BTEX samples from the Tedlar bag into the sorbent tube for GC-FID determination. Number labels: (1) Pure N2 tank; (2) N2 flow regulator; (3) Impinger bottle and cap with inlet (left side) and outlet (right side) ports (750 mL); (4) Glass tubing with a bubbler tip to evenly distribute the diluent gas; (5) Aluminum container; (6) Water heated to 25 °C; (7) Heater; (8) Temperature sensor; (9) Temperature regulator; (10) Permeation tube device for BTEX; (11) Empty 10 L Tedlar bag; (12) Tedlar bag containing BTEX; (13) Sorbent tube; and (14) Sibata vacuum pump.

Mentions: Dynacal permeation tube devices for four target VOCs [benzene (B), toluene (T), ethylbenzene (E), and m-xylene (X))] were purchased from Valco Instruments Co. Inc. (VICI Metronics Inc, Poulsbo, WA, USA). The manufacturer-published permeation rate (PR) values at each reference temperature were 16,000 (at 70 °C), 18,849 (at 80 °C), 21,774 (at 100 °C), and 21,714 ng·min−1 (at 100 °C), respectively. These same PT devices were used for our recent study for standard gas generation using a more complicated commercial dynacalibrator system [7,8]. The basic information of target compounds (e.g., structural formula, density, molecular weight, and CAS no.) and PT device (e.g., sales order no., part no., type, and PR at a certain temperature) is presented in Table 1. For this experiment, gaseous BTEX was generated at constant temperature by placing PT devices in an impinger system (750 mL volume; 6.5 cm diameter; and 24.5 cm height up to glass rim, Figure 1).


The combined application of impinger system and permeation tube for the generation of volatile organic compound standard gas mixtures at varying diluent flow rates.

Kim KH, Susaya J, Cho J, Parker D - Sensors (Basel) (2012)

Illustration of (a) the sampling device for generating gaseous BTEX standards using an impinger system and (b) the secondary sampling system for transferring BTEX samples from the Tedlar bag into the sorbent tube for GC-FID determination. Number labels: (1) Pure N2 tank; (2) N2 flow regulator; (3) Impinger bottle and cap with inlet (left side) and outlet (right side) ports (750 mL); (4) Glass tubing with a bubbler tip to evenly distribute the diluent gas; (5) Aluminum container; (6) Water heated to 25 °C; (7) Heater; (8) Temperature sensor; (9) Temperature regulator; (10) Permeation tube device for BTEX; (11) Empty 10 L Tedlar bag; (12) Tedlar bag containing BTEX; (13) Sorbent tube; and (14) Sibata vacuum pump.
© Copyright Policy
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC3472869&req=5

f1-sensors-12-10964: Illustration of (a) the sampling device for generating gaseous BTEX standards using an impinger system and (b) the secondary sampling system for transferring BTEX samples from the Tedlar bag into the sorbent tube for GC-FID determination. Number labels: (1) Pure N2 tank; (2) N2 flow regulator; (3) Impinger bottle and cap with inlet (left side) and outlet (right side) ports (750 mL); (4) Glass tubing with a bubbler tip to evenly distribute the diluent gas; (5) Aluminum container; (6) Water heated to 25 °C; (7) Heater; (8) Temperature sensor; (9) Temperature regulator; (10) Permeation tube device for BTEX; (11) Empty 10 L Tedlar bag; (12) Tedlar bag containing BTEX; (13) Sorbent tube; and (14) Sibata vacuum pump.
Mentions: Dynacal permeation tube devices for four target VOCs [benzene (B), toluene (T), ethylbenzene (E), and m-xylene (X))] were purchased from Valco Instruments Co. Inc. (VICI Metronics Inc, Poulsbo, WA, USA). The manufacturer-published permeation rate (PR) values at each reference temperature were 16,000 (at 70 °C), 18,849 (at 80 °C), 21,774 (at 100 °C), and 21,714 ng·min−1 (at 100 °C), respectively. These same PT devices were used for our recent study for standard gas generation using a more complicated commercial dynacalibrator system [7,8]. The basic information of target compounds (e.g., structural formula, density, molecular weight, and CAS no.) and PT device (e.g., sales order no., part no., type, and PR at a certain temperature) is presented in Table 1. For this experiment, gaseous BTEX was generated at constant temperature by placing PT devices in an impinger system (750 mL volume; 6.5 cm diameter; and 24.5 cm height up to glass rim, Figure 1).

Bottom Line: The performance of the impinger standard gas generation system was assessed for four aromatic VOCs (benzene, toluene, ethylbenzene, and m-xylene; BTEX) at varying flow rates (FR) of 50 to 800 mL·min(-1).Experimental results corrected by such a formula indicate that the compatibility between the APR and MPR generally increased with low FR, while the reproducibility was generally reduced with decreasing flow rate.Although compatibility between different PRs is at a relatively small and narrow FR range, the use of correction formula is recommendable for the accurate use of PT.

View Article: PubMed Central - PubMed

Affiliation: Department of Environment & Energy, Sejong University, Seoul 143-747, Korea. khkim@sejong.ac.kr

ABSTRACT
Commercial standard gas generators are often complex and expensive devices. The objective of this research was to assess the performance of a simplified glass impinger system for standard gas generation from a permeation tube (PT) device. The performance of the impinger standard gas generation system was assessed for four aromatic VOCs (benzene, toluene, ethylbenzene, and m-xylene; BTEX) at varying flow rates (FR) of 50 to 800 mL·min(-1). Because actual permeation rate (APR) values deviated from those computed by the manufacturer's formula (MPR), new empirical relationships were developed to derive the predicted PR (PPR) of the target components. Experimental results corrected by such a formula indicate that the compatibility between the APR and MPR generally increased with low FR, while the reproducibility was generally reduced with decreasing flow rate. Although compatibility between different PRs is at a relatively small and narrow FR range, the use of correction formula is recommendable for the accurate use of PT.

Show MeSH
Related in: MedlinePlus