Calculations, Quality Control, and Statics Flashcards
How many grams of sodium hydroxide (NaOH)
are required to prepare 150.0 mL of a 5.0% w/v
solution?
A. 1.5 g
B. 4.0 g
C. 7.5 g
D. 15.0 g
C
How many milliliters of glacial acetic acid are
needed to prepare 2.0 L of 10.0% v/v acetic acid?
A. 10.0 mL
B. 20.0 mL
C. 100.0 mL
D. 200.0 mL
D
Convert 10.0 mg/dL calcium (atomic weight = 40.1)
to International System of Units (SI).
A. 0.25
B. 0.40
C. 2.5
D. 0.4
C
Convert 10.0 mg/dL calcium (atomic weight = 40.1)
to International System of Units (SI).
A. 0.25
B. 0.40
C. 2.5
D. 0.4
C
Convert 2.0 mEq/L magnesium (atomic
weight = 24.3) to milligrams per deciliter.
A. 0.8 mg/dL
B. 1.2 mg/dL
C. 2.4 mg/dL
D. 4.9 mg/dL
C
How many milliliters of a 2,000.0 mg/dL glucose
stock solution are needed to prepare 100.0 mL of a
150.0 mg/dL glucose working standard?
A. 1.5 mL
B. 7.5 mL
C. 15.0 mL
D. 25.0 mL
B
How many significant figures should be reported
when the pH of a 0.060 M solution of nitric acid
is calculated?
A. 1
B. 2
C. 3
D. 4
B
A glycerol kinase method for triglyceride calls for a
serum blank in which normal saline is substituted
for lipase in order to measure endogenous glycerol.
Given the following results, and assuming the
same volume of sample and reagent are used for
each test, calculate the triglyceride concentration
in the patient’s sample.
A. 119 mg/dL
B. 131 mg/dL
C. 156 mg/dL
D. 180 mg/dL
B
Which of the following quality control (QC) rules
would be broken 1 out of 20 times by chance alone?
A. 12s
B. 22s
C. 13s
D. 14s
A
Which of the following conditions is cause for
rejecting an analytical run?
A. Two consecutive controls greater than 2 s above
or below the mean
B. Three consecutive controls greater than 1 s above the mean
C. Four controls steadily increasing in value but less
than ±1 s from the mean
D. One control above +1 s and the other below –1 s
from the mean
A
One of two controls within a run is above +2s
and the other control is below –2s from the mean.
What do these results indicate?
A. Poor precision has led to random error (RE)
B. A systematic error (SE) is present
C. Proportional error is present
D. QC material is contaminated
A
Two consecutive controls are both beyond –2s
from the mean. How frequently would this occur
on the basis of chance alone?
A. 1:100
B. 5:100
C. 1:400
D. 1:1,600
D
The term R4S means that:
A. Four consecutive controls are greater than ±1
standard deviation from the mean
B. Two controls in the same run are greater than
4s units apart
C. Two consecutive controls in the same run are
each greater than ±4s from the mean
D. There is a shift above the mean for four
consecutive controls
B
A trend in QC results is most likely caused by:
A. Deterioration of the reagent
B. Miscalibration of the instrument
C. Improper dilution of standards
D. Electronic noise
A
In most circumstances, when two controls within a
run are both greater than ±2s from the mean, what
action should be taken first?
A. Recalibrate, then repeat controls followed by
selected patient samples if quality control is
acceptable
B. Repeat the controls before taking any corrective
action
C. Change the reagent lot, then recalibrate
D. Prepare fresh standards and recalibrate
A
