Coated Filters Preloaded in Cassettes, ISO-CHEK

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Part Number: 225-9022

Coated Filters Preloaded in Cassettes, ISO-CHEK Overview

Filter, ISO-CHEK®, coated, preloaded two-stage 37-mm cassette that provides separation and collection of the vapor and particulate phases of isocyanates. One PTFE filter and one glass fiber filter coated with 9-(N-methylaminomethyl) anthracene (MAMA), pk/12
Note: Does not include Derivatizing Solution, which is required for use with the ISO-CHEK Sampling System. See Cat. No. 225-9023 or 225-9023A for ISO-CHEK Cassettes with Derivatizing Solution included.

ISO-CHEK® is the only filter-based sampling system that simultaneously traps and separates both monomers and oligomers at the point of collection for highly sensitive physical and chemical characterizations of diisocyanates including HDI, MDI, IPDI, HMDI, 2,4-TDI, and 2,6-TDI. The IRSST-developed ISO-CHEK offers rapid 15-minute sampling, stable samples, and a 40% reduction in sample preparation and analysis time compared to other methods. ISO-CHEK meets ASTM D5932-96 and D6561-00 specifications and is an ideal air sampling solution for OSHA’s National Emphasis Program (NEP) on occupational exposure to isocyanates.


Performance Profile

Collection Method Dual filter cassette; 5-µm PTFE membrane traps aerosol phase, glass fiber filter impregnated with MAMA collects vapor phase
Sample Flow Rate 1 L/min
Sample Time 15 minutes
Derivatizing Reagent
(filter coating for vapor phase)
9-(N-methylaminomethyl) anthracene (MAMA)
Derivatizing Solution
(for aerosol phase)

1-(2-Methoxyphenyl) piperazine (MOPIP)
Supplied in jars containing 5 ml of solution (0.5 mg MOPIP in 5 ml toluene)

Sample Stability Can be stored at 39.2 F (4 C) for up to 10 days. Store and prepare in solvent-free environments. SKC recommends sample analysis as soon as possible.
Analysis Reverse phase HPLC with UV and fluorescence detection
Quantitation Limit 0.15 ppb for 2,4-TDI, 2,6-TDI, 1,6-HDI, IPDI, MDI, HMDI monomer
1.5 ppb for 1,6-HDI and MDI oligomers
Limit of Detection 0.2 mg/m3 for 2,4-TDI and 2,6-TDI
0.6 mg/m3 for 1,6-HDI
0.3 (UV)/0.08 (FD) mg/m3 ** for MDI
** First number is with UV detector, the second is with a fluorescence detector.


Simultaneous and Separate Collection of Isocyanate Phases

ISO-CHEK Sampling Cassette for Isocyanates 225-9022


The patented Isocyanate Sampling System is a preloaded three-piece cassette that contains two stages. Stage one contains an untreated PTFE filter to collect the aerosol phase and stage two holds a glass fiber filter impregnated with 9-(N-methylaminomethyl) anthracene (MAMA) for the vapor phase of isocyanates. This system effectively traps and separates the phases at the point of collection and offers many advantages over other methods for sampling isocyanates.

The ISO-CHEK Advantage!

Simultaneous collection and separation of phases at the point of collection: ISO-CHEK separates the vapor and aerosol phases at the point of collection for less time-consuming and more accurate analysis of each phase.

Reagent is stable at room temperature: Loss of derivatizing reagent was found under ambient conditions when using other methods.

15-minute sampling time: Isocyanates are sensitizing agents. Even short 15-minute exposures at high concentrations can lead to sensitivity in susceptible individuals. Therefore, short-term sampling provides more meaningful results than the longer sampling times required by other methods.

No handling precautions: Eliminates inconveniences of impingers.

Exploded View of ISO-CHEK Filter Cassette Cassette in image is tinted for clarification
Exploded View of ISO-CHEK Filter Cassette
(Cassette in image is tinted for clarification.)


Principle of Operation
A sample pump draws air through the ISO-CHEK cassette. Aerosols are trapped on the PTFE filter while gases pass through to the next filter. Vapors are trapped on the fiber glass filter impregnated with MAMA. A chemical reaction occurs on this filter resulting in the formation of a highly detectable urea derivative. The PTFE filter is derivatized in the field by placing it in a supplied jar containing 1-(2 methoxyphenyl) piperazine reagent (MOPIP). Monomeric and oligomeric phases are separated by using a reverse phase HPLC column with a UV detector and fluorescence detector in series.


Simply unplug and connect the cassette to a calibrated sample pump capable of at least 1 L/min. Take a 15-minute sample at 1 L/min. Immediately after sampling, open the cassette, remove the PTFE filter with forceps, match the cassette ID number with the reagent jar number, and place the filter in the prepared reagent jar. The fiber glass filter remains in the cassette. Replug the cassette, wrap it in foil to protect the sample from light, and ship the jar and cassette to an ISO-CHEK-certified laboratory.