Quiz 1 Flashcards
Introduction to Analytical Methods, Evaluating Analytical Data, Safety Rules, Toxic Chemicals, Conversion of Units
What are the 7 stages of an analytical method?
- Conception of analytical method (birth)
- Successful demonstration that the analytical method works
- Establishment of the analytical method’s capabilities
- Widespread acceptance of the analytical method
- Continued development of the analytical method leads to significant improvements
- New cycle from steps 3-5
- Analytical method can no longer compete with newer analytical methods (death)
Analytical Approach to Solving Problems:
What is Step 1?
Identify and Define the Problem
What is the problem’s context?
What type of information is needed?
Analytical Approach to Solving Problems:
What is Step 2?
Design Experimental Procedure
Establish design criteria
Identify potential interferents
Establish validation criteria
Select analytical method
Establish sampling strategy
Analytical Approach to Solving Problems:
What is Step 3?
Conduct Experiment & Gather Data
Calibrate instruments and equipment
Standardize reagents
Gather data
Analytical Approach to Solving Problems:
What is Step 4?
Analyze Experimental Data
Reduce and transform data
Complete statistical analysis
Verify results
Interpret results
Analytical Approach to Solving Problems:
What is Step 5?
Propose Solution to Problem
Is the answer sufficient?
Does answer suggest a new problem?
It provides chemical or physical information about a sample
Analysis
It determines the identity, concentration, or properties of an analyte
Analysis
It measures one or more of the analyte’s chemical or physical properties
Analysis
What do you call the component of interest in the sample?
Analyte
What do you call the remainder of the sample?
Matrix
It is any chemical or physical principle that can be used to study an analyte
Technique
It is the application of a technique for a specific analyte in a specific matrix
Method
A set of written directions stating how to apply a method to a particular sample
Procedure
A set of stringent guidelines specifying a procedure
Protocol
A technique responding to the absolute amount of analyte
Total Analysis
What are the most common signals for a total analysis technique?
Mass and Volume
A technique proportional to the relative amount of analyte in a sample
Concentration/Instrumental Techniques
These techniques are often called “classical” techniques
Gravimetry and Titremetry
What are the most common signals for a concentration/instrumental technique?
Optical and Electric signals
This technique is also known as “instrumental” techniques
Concentration/Instrumental Techniques
Spectroscopy and electrochemistry are examples of what technique?
Concentration/Instrumental Technique
This refers to how closely the results of an experiment agrees with the true or expected result
Accuracy
How can accuracy be expressed?
Absolute Error (e)
Percentage Error (%e)
A measure of variability, this refers to how closely the results of an experiment are between individual analyses.
Precision
A measure of a method’s ability to establish that the differences in the amount of analytes are significant
Sensitivity
If an analytical method’s signal depends only on the analyte, it is said to be?
Specific
A measure of a method’s freedom from interferences
Selectivity
What are the 2 common ways to estimate central tendency?
Mean
Median
What is the most common estimation of central tendency
Mean
Why is the mean a less robust estimate of central tendency than the median?
Because the mean is sensitive to extreme values while the median is not
This provides an estimate of the differences or of the uncertainty in measurements
Measures of Spread
Describes the spread of a data set’s individual values about its mean
Standard Deviation
The square of the absolute standard deviation
Variance
What formula is this:
e = Mean - µ
Absolute Error
What formula is this:
%e = [(Mean - µ) / µ] * 100
Percent Relative Error
What do you call errors affecting the accuracy of an analysis?
Determinate Error
This error occurs when the sampling strategy does not provide a representative sample
Sample Error
This error occurs when defective experimental methods are adopted
Method Error
This error occurs when the instruments and/or equipment used during analysis are not properly calibrated
Measurement Error
This error occurs when the researcher commits the error themselves
Personal Errors
This type of determinate error is the same for all samples and is more significant when analyzing smaller samples of different sizes
Constant Determinate Error
This type of determinate error depends on the amount of sample and is more difficult to detect
Proportional Determinate Error
What are the 2 types of precision?
Repeatability
Reproducibility
What errors affect precision, characterized by random variations in magnitude and direction?
Indeterminate Error
This type of error tends to cancel, provided that enough measurements are made
Indeterminate Error
Type of Precision:
When a single catalyst completes the analysis in a single session using the same solution, equipment, and instrumentation
Repeatability
Type of Precision:
Under any other set of conditions, including between analyst or laboratory sessions for a single analyst; cannot be better than its repeatability
Reproducibility
Measuring devices are subject to this error due to limitations in reading its scale
Indeterminate Error
The difference between a single measurement or result and its expected value
Error
The range of possible values for a measurement or result
Uncertainty
This is done to determine whether the difference between two or more values is too large to be explained by indeterminate errors
Significance Testing
This hypothesis states that indeterminate error is sufficient to explain any differences in the data
Null Hypothesis
H0
This hypothesis states that the differences are too great to be explained by random error and, therefore, must be determinate
Alternative Hypothesis
Ha
Defines the probability that we reject the null hypothesis when it is in fact true
Confidence Level
α = 1 - confidence level/100
What are the 4 steps for a statistical analysis of data?
- Pose a question and state the null and alternative hypotheses
- Choose a confidence level for the statistical analysis
- Calculate an appropriate test statistic and compare it to a critical value
- Either retain the null hypothesis or reject it
Defined as the ability of a chemical to cause a harmful effect after a single exposure
Acute Toxicity
Refers to clothing, eyewear, gloves, helmets, footwear, and other garments that provide protection to the wearer from bodily injury or exposure
Personal Protective Equipment
A globally recognized source of information for the inherent properties, safe handling guidelines, and hazards of a chemical
Material Safety Data Sheet
What are Class A fires and what can be used to extinguish it?
Flammable Materials
- Water
- Dry Chemical Powder ABE
- Carbon Dioxide
- Foam
- Wet Chemical
What are Class B fires and what can be used to extinguish it?
Flammable Liquids
- Dry Chemical Powder ABE
- Dry Chemical Powder BE
- Carbon Dioxide
- Foam
What are Class C fires and what can be used to extinguish it?
Flammable Gases
- None
What are Class D fires and what can be used to extinguish it?
Flammable Metals
- None
What are Class E fires and what can be used to extinguish it?
Electrical Equipment
- Dry Chemical Powder ABE
- Dry Chemical Powder BE
- Carbon Dioxide
What are Class F fires and what can be used to extinguish it?
Cooking Fats and Oils
- Dry Chemical Powder BE
- Foam
How to use a fire extinguisher?
Pull the pin
Aim at the base of fire
Squeeze lever
Sweep side to side
