[Dioxin-l] real-time flue PCDD/F analysis

[Sam McClintock]

Dioxins and furans are typically measured using an extractive technique
while the incineration is running.  A sample probe is placed in the smoke
stack or exhaust vent after incineration.  The probe can be placed before
and after pollution control technology to measure the capture efficiency of
various devices.

Air is drawn through the probe into a collection media (XAD) and then
through several water impingers and silica gel to remove moisture from the
gas stream, the gas passes through a dry-gas meter, which is used in
conjunction with the experiment to determine the amount of gas the sample
was collected in.   The XAD sample is extracted for dioxins and furans, and
analyzed by GC/MS.  Two to four weeks later you get an answer back (unless
you own the lab, then it is two days later).

you can find the USEPA version of this method at:
<http://www.epa.gov/ttn/emc/promgate.html>
listed as method 23.

Real-time analysis (as the gas if moving by) is extremely hard using
current technology, though we are getting closer.  Most of the research
methods use a combined form of extractive sample with on-site GC/MS, or use
FTIR analysis by drawing the gas into a sample environment with a long IR
path-length (tube with mirrors and equivalent pathlength of 10 meters
plus).  Most of the methods are problematic because of the normal
concentration values we are looking for - nanograms per cubic meter.

Sam McClintock
mac@ensanity.com



Tony Tweedale wrote:

> Date: Thu, 03 Feb 2000 16:55:17 +0800
> From: Yao <yaoq@tsinghua.edu.cn>
> To: dioxin-l@venice.essential.org
> boundary="------------75632B561858DA8F4F276263"
> Subject: [Dioxin-l] online monitor of dioxins in flue gas
>
> This is a multi-part message in MIME format.
> --------------75632B561858DA8F4F276263
> Content-Type: text/plain; charset=gb2312
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>
> I would like to find a method to measure the dioxins emission from
> incineation gas on line on site. I am wondering if anyone has tried to
> measure the dioxin online  or anyone who has the expeience to do so. If
> so, it will be very helpful to us.
>
> Qiang Yao
>
> --------------75632B561858DA8F4F276263
> Content-Type: text/x-vcard; charset=gb2312;
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> n:Yao;Qiang
> x-mozilla-html:FALSE
> adr:;;Department of Thermal Engineering, Tsinghua
> University;Beijing;;100084;P.R.China
> version:2.1
> email;internet:yaoq@tsinghua.edu.cn
> title:Professor
> tel;fax:0086-10-62770209
> tel;home:0086-10-62773969
> tel;work:0086-10-62782108
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> fn:Qiang Yao
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