APPLICATION NOTE
Continuous Monitoring of Dichloromethane in
Manufacturing Cooling Water Using CMS5000
OVERVIEWThis application note describes the benefits of using
the fully automated on-site CMS5000 Monitoring
System to identify, analyze, report and alert users
when dichloromethane in manufacturing cooling water
exceeds acceptable limits.

INTRODUCTION
Given its abundance and proximity, water is often used
as a coolant in manufacturing facilities1. If this water isdischarged to a public water source, the manufacturer
must ensure that contaminants have not been added tothe water during the cooling process.
Dichloromethane is a common manufacturing
by-product frequently found in cooling water. It is
used as a solvent in the production of paint stripper,
pharmaceuticals and electronics2. Dichloromethane
is a potential carcinogen and may also cause
damage to the central nervous system3. Most world
governments have maximum exposure limits set fordichloromethane4. The USEPA has set an exposure
limit of 5 ppb in drinking water5. Due to thehazardous effects of dichloromethane, on-site
detection and quantitation are necessary to ensure
human safety.
CMS5000 employs Situ-Probe™ purge-and-trapsampling technology, gas chromatographic separation,and Micro-Argon Ionization Detection (MAID) to reliably
monitor concentrations of volatile organic compounds,
including dichloromethane, in water. The unit isdesigned to operate autonomously, analyzing
numerous samples per day over several months
without user supervision, and is ideally suited formonitoring of continuous manufacturing operations.
The software allows an operator to view concentration
data in real time with minimal effort. Data collectedfrom the calibrated CMS5000 allows users to makeinformed decisions about their water coolant treatment

processes. Alarms can be set to indicate whenuser-defined concentration thresholds are exceeded.

EXPERIMENTAL
Calibration standards were prepared at 1, 50, 100, 200and 500 ppb by spiking 2 L of VOC-free water with theappropriate amount of a 1000 μg/mL dichloromethanestandard in water (SPEXCertiPrep). The 1 ppb
standard was created by injecting 2 μL of the1000 μg/mL standard into 2 L of water and setting theconcentrator fill time to 10 seconds. The otherstandards were created by injecting 100 μL of the1000 μg/mL standard into 2 L of water setting theconcentrator fill time to 10, 20, 40 and 100 seconds.
Figure 1 shows a chromatogram of the 100 ppb
calibration standard. Using argon carrier gas, theanalyte was purged from the calibration standard into
the sampling tube headspace. The headspace sample
was collected onto the Tri-Bed Concentrator. The
analyte was thermally desorbed from the concentrator
and then separated on a capillary column using a
10 minutes, 30 seconds temperature programmedmethod. The retention time of dichloromethane was
4 minutes, 10 seconds. A five point calibration curvewith quadratic fit was generated from the data.
The calibration curve was validated by analyzing aknown sample at 75 ppb. Recovery was measured
at 92.8%.

CONCLUSION
The fully automated CMS5000 Monitoring System isideally suited to continually monitor dichloromethane
concentrations in manufacturing cooling water at
ranges of 1 ppb to 500 ppb. Upon implementation, thisunit provides actionable dichloromethane alerts to plant
operators, reducing discharge risks and improving
peace of mind.

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Continuous Monitoring of Dichloromethane in Manufacturing Cooling Water Using CMS5000

REFERENCES
1

Center for Climate and Energy Solutions, "Cooling Water
Intake Structures"
http://www.c2es.org/federal/executive/epa/Cooling-Water-Intake-Structures

2

EPA US Environmental Protection Agency, "Health
Effects Notebook for Hazardous Air Pollutants"
https://www3.epa.gov/airtoxics/hlthef/methylen.html

3

EPA US Environmental Protection Agency, "Health
Effects Notebook for Hazardous Air Pollutants"
https://www3.epa.gov/airtoxics/hlthef/methylen.html

4World Health Organization, "Dichloromethane inDrinking-water: Background document for development of
WHO Guidelines for Drinking-water Quality." 2003.

5EPA US Environmental Protection Agency, "What are
EPA's drinking water regulations for dichloromethane?"https://safewater.zendesk.com/hc/en-us/articles/2120769
37-4-What-are-EPA-s-drinking-water-regulations-for-dichl
oromethane-Figure 1 Chromatogram of 100 ppb Dichloromethane Calibration Standard

Column: DB-1, 30 m, 0.32 mm id, 4.0 μm df; Conc Fill: 40 s;
Temperature Profile: 50 °C (hold 4 min. 30 s) to 200 °C at 30 °C/min (hold 1 min)www.inficon.com

reachus@inficon.com

Due to our continuing program of product improvements, specifications are subject to change without notice.
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dicg26a1© 2017 INFICON

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