X-ray Diffraction Study Of New York City Aerosols Particles

Junior Nkrumah Summer Program of 2007 CCNY

Dr. Jeff Steiner Ph.D. Student Nick Steiner

Dr. Liz Rudolph

Abstract

Introduction The study of Aerosols in New York City has

been one of the major studies in the New York State.

Aerosols are suspensions of small solid or liquid particles.

Aerosols can be dust particles. These dust particles may be dangerous to human health.

Dust particles can cause contamination and can effect many parts of our earth system.

In 2000-2003 scientists from different locations measured gaseous aerosols HCL, HNO3 and NH3

in the Bronx and Manhattan.

When the measurements were collected and tested, large concentrations were observed in

both boroughs. Scientists discovered that chemicals that were collected originated in wind parcels from from south to west of

New York. City

Materials and Methods/sampling

X-ray diffraction is used to identify compounds in

unknowns by recognizing structures.

When a sample is being analyzed by X-ray diffraction, the

beam (x-ray) hits the sample. If the sample is a solid, the x-ray will be

diffracted and give us unique shapes and pattern.

E bam (Met-one E bam) is a portable real-time beta

gauge.

E bam is the most reliable machine ever built. Its ability to collects aerosol particles is

very interesting.

Diagram of (XRD)

http://images.google.com/imagehttp://images.google.com/image

In the XRD there is a x-ray (beam) that hits the

aerosols.

Diffracted rays are directed to and counted by the

spectrometer.

Data/Results

Pink lines represents 6-27-07 a

Blue lines represents 6-26-07 a

The height of the peaks are reflection of how much material and minerals that are presented. 2-theta shows the angle of the X-ray(XRD) to give us the structure of the samples

Experimental SetupMet-one E bam was set up on the roof of the administration building. Air samples were collected for 24

hours. Particles that were collected on the silica ribbon filter paper are then taken to the lab for analysis.

The Aerosols on the Filter paper were placed in a petri dish for storage.The sample, was then removed and placed on a (XRD) background free sample holder.

The slide is then placed in the XRD and examined with a program evaluating 2-theta angles from 15 to 55 degrees lasting for about 50 minutes.

When samples are done, we then use the Philips computer program Identify, to find the compounds present.

We are getting closer to identifying and classifying

aerosols by composition based on the differences between

diffractograms from day to day.

We will be using X-Ray Fluorescence (XRF) to find and

identify the metals in the aerosols samples

We need to identify large scale changes and figure out how weather patterns affect the composition of aerosols.

http://images.google.com/image

E bam diffractogram 6-27-07 a and 6-26-07 a

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10 15 20 25 30 35 40 45 50 55

2-theta

Inte

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Materials and Method analysis

This research is the study of Aerosols in New York City.

Aerosols particles can cause acid rain as well as cardiovascular and respiratory

problems.

Due to the increasing population and pollution in New York City aerosol

concentration is increasing.

Some aerosols are produced naturally (pollen, spores) and others originate from burning fossil fuels, human activities and

organic molecules.

To determine aerosol concentration in NYC, samples are collected by using a system

called, Met-One E Bam and determine the aerosol composition, we use X-ray

diffraction, which is used to find compounds in the sample by recognizing the structure.

Discussion/Conclusion

These results are significant because they help the investigator to identify the particles. Also with these results the investigator will be able to figure out the origins of these particles.

One interesting observation about these results is that even though the scans were taken on different days they have similar

results.

Center for Nanoscale Photonics

C

PN

SponsorsNational Aeronautics and Space Administration (NASA)NASA Goddard Space Flight Center (GSFC)NASA Goddard Institute for Space Studies (GISS)NASA New York City Research Initiative (NYCRI)ContributorsDr. Jeff Steiner- Professor Of Geochemistry City College Of New York.Dr. Elizabeth Rudolph- Professor Earth Science City College of New York.Ph.D. student Nick Steiner -City College of New York.

Future work

References

www.outreach.phy.cam.ac.uk/camphy/xraydiffraction/xraydiffraction3

Mage, D., Ozolins,G., Peterson,.P Webster, A, Orthofer, R Vandeweerd, V.,Gwayne, M., 1996. Urban air pollution in

megacitices of the world

indarticles.com/p/articles/mi_m0HST/is_5_4/ai91913259 26k

1 -www.giss.nasa.gov/

dept.physics.upenn.edu/~

heiney/talks/hires/whatis.html