Pollen Sample

When using the Scanning Electron Microscope (SEM) we received numerous suggestions on what types of samples would be interesting to research. Dr. Kolonko recommended us to look at a pollen sample taken from outside. The sample was taken on Siena Campus outside between Roger Bacon and Foy Hall. There was an abundance of pollen that had been collected on the concrete. Using a sterile glove and plastic bag, we carefully collected our sample and immediately transported it to our work station in the SAInT Center. Below is the raw image of our pollen sample.

Below is the image of Tristen Protzmann and Asaph Ko loading the pollen sample into the SEM. Notice the amount of care that went into the prepping of the pollen sample. Gloves are always necessary when handling and prepping the sample. 

Below is the first scan of our data with the raw image still a part of the map data. This helps us to see what and where each element is on the sample itself. By keeping the raw image in the background we can easily identify the location of each trace of an element with respect to the others. Next we removed the raw image from the background so we only see the element trace. 

Below is the image of our Map Data without the raw image. The SEM scans the sample of elements and the ones that are detected show up after around 10 minutes of scanning. The elements we found are Magnesium, Aluminium, Silicon, Phosphorus, Sulfur, Potassium, Calcium, Iron, and Molybdenum. We color coded each element so it is easier for the viewer to see where each element is located on the sample. We had to eliminate Carbon and Oxygen because of the Carbon Tape used and the Oxygen in the adhesive part of the tape . These elements cannot be taken into account when collecting our data for the pollen. 

Below is our spectrum for our pollen sample. The spectrum gives proof of each elements existence. According to where each peak/bump is located is how we can know if it is actually in or on the sample. Sometimes multiple peaks can be found of the same element. This is because there are multiple energy levels for the same element. Detectability limits can be as low as 0.2% for the higher atomic number elements. 

When the incident beam bounces through the sample, it creates secondary electrons. It leaves thousands of the sample atoms with holes in the electron shells where the secondary electrons used to be. If these "holes" are in inner shells, the atoms are not in a stable state. To stabilize the atoms, electrons from outer shells will drop into the inner shells. However, because the outer shells are at a higher energy state, to do this the atom must lose some energy. It does this in the form of X-rays.

Potassium made up most of this pollen sample at 37%. This can clearly be seen in our spectrum, as well as, in the data table below that we created once we quantified our data. The element that was least prevalent was Iron at 0.18%. Quantifying our data helps us to see the percentages of each element in our samples.  

Bruker Nano GmbH, Germany				6/3/2016
	Quantax
Results	Dust 1
Date:	6/3/2016
Element	AN	series	[wt.%]	[norm. wt.%]	[norm. at.%]	Error in wt.% (1 Sigma)
Magnesium	12	K-series	0.558314095	4.330115865	6.340675877	0.059847136
Aluminium	13	K-series	2.648438379	20.54048993	27.09416217	0.159825457
Silicon	14	K-series	0.602036207	4.669211392	5.916883769	0.054060242
Phosphorus	15	K-series	0.76617062	5.942188434	6.827852843	0.057869388
Sulfur	16	K-series	0.318741483	2.472062888	2.743761692	0.038531045
Potassium	19	K-series	4.824221496	37.41520809	34.05822043	0.174696064
Calcium	20	K-series	1.952898303	15.14609071	13.45012047	0.085014123
Iron	26	K-series	0.024141573	0.187234768	0.119321392	0.02702308
Molybdenum	42	L-series	1.198782772	9.297397914	3.449001362	0.071902244

Something interesting that we found in this sample was Molybdenum. It was the only L-series element we found, and we rarely find Molybdenum in any of our samples that we put into the SEM. Even though on the spectrum it does not appear that there is any bump, or that it is too small to be accounted for, when we quantified the sample we found that Molybdenum was 9.29% of our sample. For example, Phosphorus has a more prominent bump than Molybdenum yet Phosphorus only has 5.9% while Molybdenum has 9.29%. Further research will help us determine why this is the case. However, Molybdenum is most likely not in the sample due to the minimal peak in the spectrum.

Above here is a copy of the Microsoft Excel Spreadsheet that the SEM provides its operator after quantifying a sample. For those that are unfamiliar with quantifying a sample on the SEM here's a brief overview. Quantifying a sample helps the operator know exactly how much of an element is in the sample they are looking at. Above you can see the percentages of each element. When it says the

following:

Bruker Nano GmbH, Germany                   Quantax it is a signature provided by Bruker Nano Company in Germany. It reminds the operator of who generously provided us with this machine and is helping us in our research. The Normal Weight Percentage (normal wt%) is what we mainly are concerned with when looking at samples.