Spectrophotometer Basics

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What is the purpose of accreditation?

Provide reliable test results

To issue licenses to individuals

To certify private organizations

To evaluate and recognize a program of study or an institution as meeting certain standards (correct)

What type of specimen is collected within 30-60 minutes after the dose of a therapeutic drug?

Random sample

Trough sample

Peak sample (correct)

Fasting sample

Why is it important to collect blood samples in a specific order?

To ensure proper labeling of samples

To ensure proper mixing of anticoagulants

To prevent contamination of blood culture tubes (correct)

To prevent clotting

What is the term for the evaluation of an individual's competence by a government agency?

Licensure Signup and view all the answers

What is the reason for rejecting a specimen that is not collected in a fasting state when required?

Non-fasting specimen Signup and view all the answers

What is the term for the evaluation of an individual's competence by a private organization?

Certification Signup and view all the answers

What is the relationship between absorbance and concentration according to Beer's Law?

Absorbance is directly proportional to the concentration Signup and view all the answers

What is the purpose of the light source in a spectrophotometer?

To provide a source of light for the reaction Signup and view all the answers

Which of the following is an exception to the rule that cuvettes must be transparent?

Reflectance photometry Signup and view all the answers

What is the role of the monochromator in a spectrophotometer?

To isolate the specific light of interest Signup and view all the answers

What is the formula that represents Beer's Law?

A = abc Signup and view all the answers

Which of the following light sources cannot provide UV light?

Tungsten-halogen lamp Signup and view all the answers

What is the mass in milligrams of 3.5 grams?

35000 Signup and view all the answers

What percentage of alcohol is needed to make 1L of 70% alcohol if 95% alcohol is used?

73.7% Signup and view all the answers

What is the molar mass of anhydrous Na2SO4?

142 Signup and view all the answers

How much of the hydrated salt Na2SO4·10H2O is needed to replace 8.0g of the anhydrous salt?

18.14g Signup and view all the answers

What is the dilution ratio if 3mL of sample is mixed with 12mL of diluent?

1:5 Signup and view all the answers

What is the anion gap if the sodium level is 140, chloride level is 87, and bicarbonate level is 35?

13 Signup and view all the answers

What is the purpose of the photodetector in a spectrophotometer?

To convert transmitted light energy into electrical energy Signup and view all the answers

What type of cuvettes are used in reflectance photometry?

Opaque cuvettes Signup and view all the answers

What is the order of draw for venipuncture and vacutainer tube?

Citrate Heparin EDTA Fluoride Signup and view all the answers

What is the purpose of wiping/cleaning the exterior portion of the cuvette?

To prevent the light from being bounced off Signup and view all the answers

Why must LDH specimens be stored at room temperature?

It is a cold-labile enzyme Signup and view all the answers

What is the unit of measurement produced by the readout device?

Percent transmittance Signup and view all the answers

What is the median in a set of numbers?

The middle value when arranged in order Signup and view all the answers

Why is it impossible for the spectrophotometer to measure the light attached to the analyte?

Because the light is absorbed by the analyte Signup and view all the answers

What is the relationship between percent transmittance and absorbance?

Percent transmittance is inversely proportional to absorbance Signup and view all the answers

What is the purpose of measures of central tendency?

To reflect the accuracy of the data Signup and view all the answers

What is the function of standard deviation?

To reflect the variation of data values around the mean Signup and view all the answers

What is the coefficient of variation?

A relative indicator of precision Signup and view all the answers