summary report for june2014 ftir testing event respond succeed prepare respond succeed ftir and...

PREPARE ● RESPOND ● SUCCEED™

Prepare

Respond

Succeed

FTIR and Raman

Proficiency Program

Steven H. Hinrichs, M.D., Director, Nebraska Public Health Laboratory David Moran, MT(ASCP), Program Coordinator

985900 Nebraska Medical Center

Omaha, NE 68198-5900 Phone: (402) 559-3557

Fax: (402) 559-7799 [email protected]

Summary Report for June2014 FTIR Testing Event

The October 2014 FTIR testing event had one mixed sample, one pure sample, and one sample mixed with an

IR-inactive substance. There were 20 reporting agencies. FTIR14-7 was 1,3-propanediol. It is a colorless,

viscous liquid. It is used in industry mainly for the production of polymers. The previous PT event had 1,2-

propanediol (propylene glycol), and of course the compounds have a similar structure. However, the FTIR

was able to differentiate between the two consistently, as both have pretty sharp spectra. Here are the

absorbance spectra of 1,3 in red and 1,2 in blue.

The majority of participants correctly identified this, while all participants noted that the compound was a

diol.

FTIR14-8 was an amalgam of urea and phosphate-buffered saline tablets. The amalgam was made using a

mortar and pestle, and the mixture was white, coarse, and slightly crystalline. Microscopically the urea

crystals stand out slightly. The following screen shot shows the spectrum on the IlluminatIR when centered

over a urea crystal (red) compared to the library match for urea (blue).


Prepare

Respond

Succeed

FTIR and Raman

Proficiency Program



Omaha, NE 68198-5900 Phone: (402) 559-3557


The next screen shot shows the spectrum on the IlluminatIR when centered over a PBS crystal (red) compared

to the library match for sodium phosphate (blue). The spectrum had lower absorbance.

Regarding the sample as a whole, the IlluminatIR predominately came up with urea as a match. When the

laser hit a mixed area, the results were also mixed. The spectra looked different for these areas, and most of

the time our IlluminatIR gave a match for something obscure. The IlluminatIR seldom came up with urea as a

match in these mixed areas, so it had to be actively searched and then subtracted. When urea was


Prepare

Respond

Succeed

FTIR and Raman

Proficiency Program



Omaha, NE 68198-5900 Phone: (402) 559-3557


subtracted out and a search done on the residual, sodium phosphate always came up as the match. The

following screen shots show this.

Here is the spectrum for a mixed area.

Here is the residual after urea is subtracted (red) compared to sodium phosphate (blue).

The majority of participants responded either urea or sodium phosphate. Several responded with a mixture

of both. We suppose that with a systematic approach both compounds could consistently be found. This

would consist of seeing urea as a strong result in 1 or 2 areas and then seeing a poor match in the mixed


Prepare

Respond

Succeed

FTIR and Raman

Proficiency Program



Omaha, NE 68198-5900 Phone: (402) 559-3557


areas. Knowing that urea was likely present, it would have to be actively searched and then subtracted when

looking at a mixed area with poor matches. This is admittedly more complicated than the usual steps

probably taken by most participants.

FTIR14-9 was a white powder containing large white crystals along with smaller white crystals. The large

crystals looked like typical table salt. The powder was a mix of table salt and DL-methionine, a sulfur-

containing amino acid. Under the scope the salt crystals were large and cubical. Below is a picture from the

microscope of a large salt crystal with the methionine crystals in focus underneath.

The table salt is IR-inactive so the spectra that were found consistently matched some form of methionine.

The majority of participants correctly identified this. As always, please contact us with any questions.


Prepare

Respond

Succeed

FTIR and Raman

Proficiency Program



Omaha, NE 68198-5900 Phone: (402) 559-3557


Event Performance:

A summary of results reported is shown in the following table:

PT ID

Participants

N=20

Match Partial Match No Match Comments

FTIR14-7 1,3-

Propanediol

18 2 -

FTIR14-8

PBS

Tablet/Urea

Mix

3 12 5

FTIR14-9

Table Salt/DL-

Methionine

Mix

19 - 1

FTIR Instrument Distribution by Participating Laboratories

IlluminatIR

HazMatID

Nicolet 6700

Nicolet Avatar

Smiths TravelIR

Thermo Tru Defender

PE SpectrumOne

Nicolet iN10

summary report for june2014 ftir testing event respond succeed prepare respond succeed ftir and...

Documents