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Winter 2002 Vol. 7/1

I n f o r m a t i o n f o r P r a c t i c i n g C h e m i s t s a n d S p e c t r o s c o p i s t s

PIKE Technologies Tel: (608) 274-2721 Fax: (608) 274-0103 E-mail: sales@piketech.com

Join Us at Pittcon 2002

PIKE preparations for Pittcon 2002 are proceedingin high gear. This year, PIKE Technologies will beparticipating in the Pittsburgh Conference ofAnalytical Chemistry and Spectroscopy for the11th year in a row. And yes, again it’s being heldin the familiar location of New Orleans, Louisiana,which it seems we’ve seen a lot of in recentyears. But no worries, PIKE will be doing theirpart to make this year’s event very different andunique. Our theme for this year’s show can besummed up in one exciting three letterword……………….NEW!

Just about everything in the PIKE booth (NUMBER325) will have a new look this year. For starters,we will have a new booth design, new boothcolors (see drawing above), new graphics andsome new people in the booth looking forward tomeeting you. In addition to the familiar faces ofDennis Shanks (11th year) and Dave Engerman(7th year), our newest members of the PIKE team,Scott Little and Dr. Gabor Kemeny, will beattending this year’s conference as well. Besure to stop by our BOOTH NUMBER 325 andsay hello.

Most importantly, PIKE has a lot of new productswe will be introducing at this year’s PittsburghConference. Here’s a sneak peek at just someof the new things you’ll see:

- IntegratIR™, Near Infrared Integrating Sphere- Peltier temperature controlled liquid

transmission cell- 6x Beam Condenser Systems- 300mm wafer stage for IR Microscopy- KRS-5 Diamond MIRacle™ crystal plate- New pressure clamps for MIRacle™ &

HATR’s- Downward looking 30 Spec with disposable

sample card for reflectance- Enhanced aesthetics/ergonomics on our

automated systems

VISIT US AT BOOTHNUMBER 325!!

New Products

PIKE Prepares for Pittcon

Pittcon 2002New productsMIRacleTM ComparisonsPittcon PaperSpecial Promotions$1000 AnswerPittcon Contest2002 Shows

IN THIS ISSUE

The PIKE Peltier temperature controlleddemountable liquid cell has all the features of ourstandard demountable cells, but with the addedcapability of rapid heating and cooling throughthe use of peltier cooling devices surroundingthe cell. Useful for many life science applications,the Peltier cell can be cooled to near freezingand heated to well above 100 degrees C.

The IntegratIR™ is a high performance NearInfrared Integrating Sphere, which fits into thesample compartment of most commercial FTIRspectrometers. This accessory is ideal forsamples too difficult for more conventional diffusereflectance experiments, such as many foods,grains, soils and pharmaceutical samples.

The IntegratIR™ comes standard with a 2”diameter gold coated sphere, transfer optics,various sample mounting attachments and a built-in InGAs detector that plugs directly into thespectrometer. Priced at $8,750, the IntegratIR™is just what you would expect from PIKE, a greatvalue.

The IntegratIR™

The PIKE beam condensers are available in 4xand 6x magnifications. These accessories areperfect for mounting diamond anvil cells or othersamples requiring more infrared energy througha smaller area. It also comes standard with anenclosure for purging the optical path and a doorto access the sampling area.

PIKE Reflections Page 2

PIKE Technologies Tel: (608) 274-2721 Fax: (608) 274-0103 E-mail: sales@piketech.com

Map to Booth 325

ZnSe - DIAMOND

ZnSe

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Finally, as in the past few years, PIKE will be apart of Spectroscopy Central. This year the groupmembers include:

Axiom Analytical – FTIR, NIR, UV-Vis sampleinterfacing and multiplexing equipment – booth316High Pressure Diamond Optics (HPDO) –Diamond anvil cells – booth 317Infrared Analysis – Long path gas cells,reference spectra and gas analysis software –booth 322Molecular Microspectroscopy Laboratory(MML) – Research and educational services –booth 323MTEC Photoacoustics, Inc. – Photoacousticdetectors – booth 319PIKE Technologies, Inc. – Manual andautomated accessories for FTIR, NIR, Raman andUV-Vis Spectroscopy – booth 325SensIR Technologies – FTIR and diamond ATRsystems – booth 225

The PIKE MIRacle™ is the only single-bounceATR accessory that offers such a wide varietyof crystals. We often get questions fromcustomers regarding the best choice for certainapplications. This is why we thought a briefoverview of the choices, their basic advantagesand disadvantages, could be helpful.

The basic design of the MIRacle™ is very flexibleand modular. One can replace both the clampingmechanism and the ATR crystals very easily. Theheart of the accessory is a multifunctional plateto which sampling devices, such as the flow-through cell, connect. The plate contains both apatented (*) focusing element and the attenuatedtotal reflection element.

In this issue we will be comparing the variousversions of these plates containing a variety ofoptical materials. The discs are prealigned, pinned-in place, easily removable and readilyinterchangeable.

On the same chart (blue trace) a DiamondMIRacleTM is also shown. In this design, a 2 mmdiameter diamond is bonded on top of the ZnSefocusing element, such that the sample onlycomes in contact with the very hard andchemically resistant diamond. The energythroughput of the diamond is better in thefingerprint region, however it does have someinfrared absorption in the 1800-2300 cm-1 region.The absorption is only partial, thus analyte bandsin this region can still be measured.

The basic plate design has a complex opticalelement manufactured from IR transmittingmaterials. The optical element collects theincoming infrared beam, focuses it onto thecenter where the total reflection occurs, thendirects the beam back onto the detector locatedin the spectrometer. The infrared beam has asignificant pathlength through the opticalelement, thus the type of optical material dictatesthe useful wavelength range of the accessory.

Interchangeable plates with a variety of opticalmaterials provide a wide range of options tomeasure not only varying wavelengths, but alsohardness, sensitivity (sample depth ofpenetration) and chemical resistance. Fig 2shows a ZnSe crystal (red) with the energydiminishing from around 700 cm-1,with the cutoffoccurring around 550 cm-1.

(*) US 6,128,075 and 5,965,889

Figure 2

Figure 3

Figure 1

Entrance to Hall B

TRAM

TRAM

Posters

InternetCorral

BOOTH NUMBER 325???

Of course some things should never change.That’s why as usual, PIKE will have lots of coolstuff to give away all week long. It starts withthe Tootsie Rolls and Hershey’s Kisses candythat we have always been known for, cool PIKEsunglasses, beer mugs and pens.

And this year, it even includes a contest to win aPIKE shirt or a $100 gift certificate towards thepurchase of PIKE products (For details on thecontest, see page 4). Remember you must stopby our BOOTH NUMBER 325 for your chance towin!

Here’s a map of the Spectroscopy Central area.We’re in a great spot, right near the main entrance,so make sure you stop by our booth and visitoften. Did we mention we are located in

The MIRacleTM ofSingle Reflection ATR

Germanium and silicon are also favored materialsfor ATR, due to their very high refractive indices,4 and 3.4 respectively. Substances with highrefractive indices can be measured, as well asmaterials with high specific absorption. As wewill see later, the high index means shallowerpenetration depth, which is an advantage inmeasuring very thin films of very highly absorbingmaterials.

TRAM

Entrance to Hall B

325

Posters TRAM

SpectroscopyCentral

PIKE Reflections Page 3

PIKE Technologies Tel: (608) 274-2721 Fax: (608) 274-0103 E-mail: sales@piketech.com

AMTIR

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Germanium has a wider useful wavelength rangethan silicon ( Fig 3 ). In this particular comparisonthe germanium also demonstrated betterthroughput due to the anti-reflection coating thatreduces the front-surface reflection. Silicon isover 2 times harder than germanium and almost10x harder than ZnSe which is already fairlydurable.

Figure 5Figure 4

AMTIR is a dark metallic infrared transmittingsubstance. As an optical material, it is becomingmore and more popular. Its refractive index (2.5)allows high apparent pathlength similar todiamond. AMTIR has improved chemicalresistance over ZnSe.

Another new material combination underdevelopment is KRS-5 with diamond as the ATRelement ( Fig 4. ). Whereas KRS-5 allows someinfrared transmission past the ZnSe limit, it isrelatively soft and not very abrasion resistant.Diamond, which comes in contact with the sampleis inert, hard and also transparent past 400 cm-1. KRS-5 has a 2.37 index of refraction. Anti-reflection coating is not available for KRS-5. Thisdevice is unique and useful for materials thathave critical analytical bands below 650 cm-1,such as is the case in certain pharmaceuticalapplications.

Most FTIR spectrophotometers use KBrbeamsplitters and have KBr windows on thedetectors, thus the wavelength range is limitedto 400 cm-1. Using a far infrared beamsplitterand a TGS detector with polyethylene windowhowever, we were able to measure energythrough the KRS-5 / Diamond MIRacleTM to 260cm-1.

Apart from the wavelength range, ATR crystalshave different effective optical penetration intothe sample. The penetration depth of infraredlight at the interface of total reflecting surfacecan be calculated with the following formula :

lD

p = __________________________

2πnc [sin2F - (ns/nc)2]1/2

Where:

F = Effective angle of incidence

nc = Refractive index of crystal

ns = Refractive index of sample

l = Wavelength

With ATR, the apparent pathlength through thesample is affected by the crystal and sampleindices, and the apparent angle, of incidence.The apparent angle which is a combination of thedifferent angles in the crystal, varies slightly withthe actual light path generated by the focusingelements and the ATR element.

Should you have any questions or comments,you may contact us at sales@piketech.com or at(608) 274-2721. Gabor Kemeny and ourapplications staff will be happy to help you. Auseful Excel spreadsheet is also available at nocharge to perform some of the calculations.

Only a few of our readers have the means tocompare all of these optical materials, so wethought it would be useful to demonstrate howdifferent the resultant absorption bands can be.( Fig 5 ) Nujol (a purified hydrocarbon used forpreparing emulsions and readily available in mostlaboratories) was used for the comparison.

A drop was applied on the crystal and thespectrum recorded on the same spectrometerusing the same MIRacle™ accessory.Exchanging the crystals takes less than a minute,thus it is practical and easy to use the right materialfor the various samples.

You may be using a ZnSe plate for liquids withcarbonyl bands with excellent signal-to-noiseratio. Should you need to run dark and veryabsorbing materials, such as rubber, you mayswitch to a Germanium plate. Within minutes youcan install a diamond plate and measure abrasivehard powders. To help with the choices, wecompiled a small table to serve as a guide inselecting the best ATR crystal(s) for yourapplications.

Pittcon Paper

Don’t miss the technical session 17 on“Developments in ATR Instrumentation” onMonday, March 18 in Room 262.

At 9:50 am, Dr. Ashraf A. Ismail of McGill University,in collaboration with PIKE Technologies, will begiving a talk entitled “Single Bounce ATR Analysisof Edible Fats and Oils and Alcoholic Beveragesfor Compliance with Labeling Regulations”. Thiswork was done using a special configuration ofa PIKE Heated MIRacle™ ATR flowcell.

CRYSTAL MATERIAL ADVANTAGES LIMITATIONS

Diamond with ZnSe Hard scratch-proof surface, Higher price of diamond crystal.highest throughput. Diamond absorption around 2000 cm-1Withstands highly acidic reduces throughput in that regionand basic samples.

ZnSe Excellent throughput, high penetration Can’t use strong acids.depth (more sensitivity for moderately Can’t use higher clamping pressure.absorbing samples).Economical.

Germanium (Ge) Shallower penetration depth Absorbs below 830 cm-1.(for highly absorbing samplesand very thin films). Excellentchemical resistance.

Silicon (Si) Good chemical resistance, Range is limited to 1500 cm-1.useful for highly absorbing materials. Lower throughput. No strongExcellent scratch resistance. acids or alkali.

AMTIR Resistant to acids, harder than ZnSe. Range to 725 cm-1. No alkali solutions

Diamond with KRS-5 Extended wavelength range to 260 cm-1 * Limited pressure range, limited temperature range.No anti-reflection coating . Higher price.

(*) Only with extended wavelength far-infrared beamsplitter and detector

PIKE Reflections Page 4

PIKE Technologies Tel: (608) 274-2721 Fax: (608) 274-0103 E-mail: sales@piketech.com

2901 Commerce Park DriveMadison, Wisconsin 53719

PAID

PITCON 2002, Memorial Convention Center,New Orleans, LAMarch 18-21, 2002 Booth #325

Eastern Analytical Symposium andExposition (EAS), Garden State ConventionCenter Somerset, New JerseyNovember 18-21, 2002

Pittcon 2002New ProductsMIRacleTM

ComparisonsPittcon PaperSpecial Promotions$1000 AnswerPittcon Contest2002 Shows

PIKE 2002 Show Calendar

Spring Sale

Prsrt StdU.S. Postage

Permit No. 1547Madison, WI

Universal Sample Holder

PIKE be giving away our usual promotional giftsat the show this year and this year we will bedrawing each day for a PIKE polo shirt and onThursday, all entries will be combined in adrawing for a $100 gift certificate. One entryfor each day will be allowed and entries can bebusiness cards or available lead cards. Pleasebring your business card or copy of the mailingaddress from this newsletter to enter thecompetition. The winner will be drawn onThursday March 21st. Good luck and goodlistening!

162-5600

Pittcon Contest

This cell holder has a spring-loaded mechanismwhich conveniently keeps in place films, saltplates, KBr pellets, and other materials. Theaperture of the swivel ring is 20 mm. The UniversalCell Holder is a quick and easy method for testing7 mm hand press pellets without having toremove them from the die.

160-1124 25 x 4 mm NaCl Disk160-1133 25 x 4 mm KBr Disk161-1010 7 mm Die Set

The Holder usually sells for $85, but for all orderstaken before July 1, 2002 the price will be $70.To qualify for this price this article must bementioned when placing the order. Pleaseremember, windows must be ordered separately.

$1,000 Answer

Many compounds share spectroscopic attributesor important characteristics. All data associatedwith a chemical can (and should) be used to identifyand classify unknowns.

The following numbers all involve somethingunique about our unknown chemical this issue.

0, 4, 6, 10, 100, 273, 1781, 3250

No one correctly answered the quiz this issue.Maybe the question was too hard or maybe itwas too easy to bother with. The answer wassimply, WATER. (H2O)

0 Freezing4 Maximum Density6 Six Sided Ice Crystals10 Atomic Number100 Boiling - Celsius273 Freezing - Kelvin1781 Discovery3250 Ice Spectral Range cm-1

The freezing point of water is 0 degrees Celsiusor the corresponding 273 degrees Kelvin.Maximum density is reached at 4 degrees Celsiusand the atomic number of the molecule is 10.The boiling point of water is 100 degrees Celsiusand ice crystals have six (hex) axes.

For those of us that use MCT detectors the 3250cm-1 band is a sure sign of an icing window.Lastly, Henry Cavendish was the English chemistthat first recognized in 1781 that water was acompound containing Hydrogen and Oxygen.

Be sure to enter our Pittcon contest and we hopeto see you there!!!