Micro-chemical Analysis for hire / Micro-FTIR Spectroscopy and expert analysis / Medical Devices and plastic parts / failure analysis and reverse engineering

1. Chemical Microanalysis
for Industry
State-of-the-Art Analysis for hire
Medical Device Problem Solving
Polymer Problem Solving
Industrial Problem Solving
Asbestos Analyses
etc., etc., etc.
by
John Donohue
201-294-2581

2. Hello. I’m John Donohue and this is the best Infrared Microscope ever made by
any manufacturer:
Nicolet’s IR-Plan Research Microscope
mounted on a Magna 560 Mainbench
This amazing instrument allows my Lab
to obtain the Chemical Identity, via the
Infrared Spectrum, of an area as small
as 10 microns by 10 microns
(10μX10μ). That’s as small as 9 red
blood cells placed in a 3X3 square.
When you can chemically identify
objects that small you can perform such
amazing investigations that they
can often depart completely from the
expected and traditional uses of Infrared
Spectroscopy, as you will see.
These documents will describe the type
of analyses I perform for Industry and
Publication using this instrument and
the other equipment in my Laboratory.
Part 1: Introduction to the Technology and Method

3. Mirrored “Lampshade”
Mirrored “Flying Saucer”
Hard Silicon Surface for ATR “Contact” Spectra
My IR-Plan is usually set up with Two Reflachromats:
One For Reflection And Transmission, The Other Dedicated To ATR
More “Specialized Reflachromats” and Visible Light Objectives are available, if needed
… and Visible Light Objectives for
Visible and Polarized Light Microscopy

4. Microscope Reflection Mode
Lightpath
The Upper Reflachromat objective
projects a conical surface of IR radiation
through the sample. It reflects off the
shiny metal beneath the sample and
follows the same conical surface up
through the sample, back to the
objective, and from there to the detector.
This mode is very fast and easy to
perform. The shiny metal substrate is
usually 0.005 inch aluminum sheet
taped onto a microscope slide. It is cut
from 5 inch by 5 inch sheet that is
cheap and disposable. It can also be
performed on any flat or curved metal
surface such as injection molding tool
surfaces, medical steel cannulas, engine
valves, gun metal, you name it.
To Detector
From Source
Sample
on metal
Shiny Metal Substrate
Shiny Metal Substrate

5. >The FTIR Microscope increases greatly the utility of FTIR and allows the successful
use of IR in analyses that simply could not be done by a Mainbench alone.
>The Micro - ATR Objective obtains surface spectra (of the top ~micron of material)
with almost no sample prep. This is excellent for thin coatings or surface analysis.
>The FTIR Microscope can obtain useful spectra from extremely thin samples as
small as a 10μ X 10μ Square. The amount of mass providing such a signal can
approach the Detection Limits of GC/MS
>Example - FTIR Microscope’s Limit of Detection is about a 10μ X 10μ Square :
If sample is 1μ thick, 10μ X 10μ X 1μ sample of Polyethylene = how many grams?
1cc of PE = 1g = 10mm X 10mm X 10mm = 1000 cubic mm = 103 mm =>
10mm X 10mm X 10mm = 104 μ X 104 μ X 104 μ = 1012 cubic microns =>
So: 1012 cubic microns = 1g
10μ X 10μ X 1μ =100 cubic microns = 102 cubic microns
102 / 1012 = 10-10 g
So: 10μ X 10μ X 1μ sample of Polyethylene = 0.0000000001 grams of PE
So, the FTIR Microscope can ID 100 trillionths of a gram of PE
UNIQUE ADVANTAGES OF THE FTIR MICROSCOPE
How sensitive is it? See arithmetic below.

6. Microscope ATR Mode Lightpath
The ATR Reflachromat objective
projects a conical surface of IR
radiation onto the inside of the ATR
Crystal’s Sample Contact Point. A
small part of the IR radiation
“tunnels” into the sample touching
this Contact Point. Some of it is
absorbed and the rest continues on
to the detector.
This mode is particularly well-suited
to surface analysis (surfaces that are
bioactive, drug eluting, bioresorbable,
coated, “blooming” additives,
lubricious, non-thrombogenic, etc.).
It is also a good choice for highly
absorbing materials that are difficult
to get an IR beam in and out of such as
Black Rubber.
From Source
To Detector
SampleSample

7. How Small Can Samples Be?
How small IS the 10μ X 10μ Limit of Detection?

8. Back of USA Penny
Lincoln
Memorial

9. Lincoln seated on Penny’s back
This image is 11.2mm X 8.5mm.

10. Lincoln seated on Penny’s back; mm scale to left
This image is 3.0mm X 2.3mm.

11. IR-Plan Visible Light 10X Objective view (Glass)
Lincoln’s Head and Shoulders
This image is 550μ X 420μ

12. IR-Plan IR Objective 15X Reflachromat view: Lincoln’s Head
This is the magnification at which
Knife-edge apertures are used to frame
the area to be analyzed
and FTIR Spectra are obtained.
10μ X 10μ
This image is 390μ x 300μ
Limit of
Detection:
“Lincoln’s “Eye”

13. Lincoln’s Face on the previous slide is about 140μ X 120μ.
The IR-Plan can obtain good spectra from much smaller
samples than this (see asbestos ribbon, below). The thin
polymer coating on Lincoln’s Face is easily IDd
as Polycarbonate.