(a) Interpretation: The factors related to the analyte influencing the emission intensity needs to be identified. Concept introduction: X-Ray photoelectron spectroscopy or XPS is a quantitative spectroscopic technique that is surface-sensitive. It measures the composition of materials with respect to elements in the range of parts per thousand. It also helps in determining the empirical formula, chemical state and electronic state of elements present in the materials. It is now widely used because with the help of this technique not only the element within the films, but the other elements bonded to it can be determined. For example, with the help of XPS technique, the oxidation state of metal in the metal oxide can be determined.

BuyFind

Principles of Instrumental Analysis

7th Edition
Douglas A. Skoog + 2 others
Publisher: Cengage Learning
ISBN: 9781305577213
BuyFind

Principles of Instrumental Analysis

7th Edition
Douglas A. Skoog + 2 others
Publisher: Cengage Learning
ISBN: 9781305577213

Solutions

Chapter 21, Problem 21.14QAP
Interpretation Introduction

(a)

Interpretation:

The factors related to the analyte influencing the emission intensity needs to be identified.

Concept introduction:

X-Ray photoelectron spectroscopy or XPS is a quantitative spectroscopic technique that is surface-sensitive. It measures the composition of materials with respect to elements in the range of parts per thousand. It also helps in determining the empirical formula, chemical state and electronic state of elements present in the materials.

It is now widely used because with the help of this technique not only the element within the films, but the other elements bonded to it can be determined.

For example, with the help of XPS technique, the oxidation state of metal in the metal oxide can be determined.

Interpretation Introduction

(b)

Interpretation:

The factors related to the spectrometer influencing the emission intensity needs to be identified.

Concept introduction:

X-Ray photoelectron spectroscopy or XPS is a quantitative spectroscopic technique that is surface-sensitive. It measures the composition of materials with respect to elements in the range of parts per thousand. It also helps in determining the empirical formula, chemical state and electronic state of elements present in the materials.

It is now widely used because with the help of this technique not only the element within the films, but the other elements bonded to it can be determined.

For example, with the help of XPS technique, the oxidation state of metal in the metal oxide can be determined.

Interpretation Introduction

(c)

Interpretation:

The relation between the ratio of measured quantity in XPS for analyte to the internal standard and their atomic concentrations needs to be determined.

Concept introduction:

X-Ray photoelectron spectroscopy or XPS is a quantitative spectroscopic technique that is surface-sensitive. It measures the composition of materials with respect to elements in the range of parts per thousand. It also helps in determining the empirical formula, chemical state and electronic state of elements present in the materials.

It is now widely used because with the help of this technique not only the element within the films, but the other elements bonded to it can be determined.

For example, with the help of XPS technique, the oxidation state of metal in the metal oxide can be determined.

Interpretation Introduction

(d)

Interpretation:

The given equation for the fractional atomic concentration of element A needs to be proved.

Concept introduction:

X-Ray photoelectron spectroscopy or XPS is a quantitative spectroscopic technique that is surface-sensitive. It measures the composition of materials with respect to elements in the range of parts per thousand. It also helps in determining the empirical formula, chemical state and electronic state of elements present in the materials.

It is now widely used because with the help of this technique not only the element within the films, but the other elements bonded to it can be determined.

For example, with the help of XPS technique, the oxidation state of metal in the metal oxide can be determined.

Interpretation Introduction

(e)

Interpretation:

The atomic concentration of three elements that is C, N and O in the polyurethane sample needs to be determined.

Concept introduction:

In the quantitative XPS, the measured quantity is usually I/S.

Here, I is the peak area and S is the sensitivity factor. For the analyte, the quantity measured is (I/S)a and that of internal standard is (I/S)s.

The internal standard is the concentration of a substance present in every sample needed to be analyzed.

The ratio I/S is directly proportional to the concentration on the surface.

Or,

(IS)a=Ca

Similarly,

(IS)s=Cs

Interpretation Introduction

(f)

Interpretation:

The limitations of quantitative analysis with XPS needs to be explained. The reason for atomic concentration measured to not correspond to the bulk composition needs to be explained.

Concept introduction:

X-Ray photoelectron spectroscopy or XPS is a quantitative spectroscopic technique that is surface-sensitive. It measures the composition of materials with respect to elements in the range of parts per thousand. It also helps in determining the empirical formula, chemical state and electronic state of elements present in the materials.

It is now widely used because with the help of this technique not only the element within the films, but the other elements bonded to it can be determined.

For example, with the help of XPS technique, the oxidation state of metal in the metal oxide can be determined.

Interpretation Introduction

(g)

Interpretation:

The percentage error in the atomic concentration of C, N and O needs to be determined.

Concept introduction:

For all the elements measured by XPS technique, the fractional atomic concentration for element A can be represented as follows:

fA=IA/SA(In/Sn)

Here, In is the measured peak for n element and Sn is the sensitivity factor for the peak.

The atomic concentration of C, N and O for the polyurethane sample is given 76%, 8.0% and 16% respectively.

The percentage error from the values calculated in part (e) can be calculated as follows:

%C=(|7776|)%=1%%N=(|7.788|)%=0.22%%O=(|14.616|)%=1.4%

Thus, the percentage error in the atomic concentration of C, N and O is 1%, 0.22% and 1.4% respectively.

Want to see the full answer?

Check out a sample textbook solution.

Want to see this answer and more?

Experts are waiting 24/7 to provide step-by-step solutions in as fast as 30 minutes!*

*Response times may vary by subject and question complexity. Median response time is 34 minutes for paid subscribers and may be longer for promotional offers.