Lab

Question 1

Mono chloramine symbol

Answer 1

NH2Cl

Question 2

What’s the strength of hypochlorite ion OCl- compared to hypochlorous acid?

Answer 2

1/100

Question 3

What’s the strength of monochloramine compared to hypochlorous acid?

Answer 3

1/150

Question 4

What defines precision?

Answer 4

When I repeat it do I get the same thing? Replicate samples check for Precision, the consistency of results

Question 5

2.20 for pocket 2 and +++++ for the 900

Answer 5

Out of range

Question 6

What is quality assurance?

Answer 6

A program that defines what actions are required to assure the analytical results are acceptable

Question 7

What is quality control?

Answer 7

Performing specific actions identified in the QA program. (Procedures)

Question 8

When do you calibrate a pH meter, or any other analysis?

Answer 8

When you get a new batch of samples

Question 9

What’s the equation for % recovery?

Answer 9

Sample Result / True Value. * 100

Question 10

What’s the least accurate glass?

Answer 10

Beaker

Question 11

What’s the name and symbol for trichloramine?

Answer 11

Nitrogen Trichloride NCL3

Question 12

What’s the symbol for dichloramine?

Answer 12

NHCl2

Question 13

What is the titrant when titrating for alkalinity?

Answer 13

Sulfuric acid

Question 14

What is the relationship between the method detection limit and the instrument detection limit?

Answer 14

Method is always higher than the instrument

Question 15

What is the Instrumental ldl when dpd testing?

Answer 15

0.1 mg/L

Question 16

Precision

Answer 16

How close together the results of your repeat samples are. Consistency of results

Question 17

What is the purpose of Known QC solutions?

Answer 17

Determines how close to the true value am I? Accuracy

Question 18

Accuracy

Answer 18

How close to the TV am I? Known check samples check for accuracy, or how close the result is to the actual value

Question 19

What is the Purpose of controls?

Answer 19

So you know the analysis parameters in order to determine if the analysis is in or out of control

Question 20

Things that impact getting a representative sample

Answer 20

Store temp incorrectly, sample site isn’t a good place, poor sampling training, exceeding hold time,

Question 21

The other way to test alkalinity?

Answer 21

pH instead of color change

Question 22

MPN?

Answer 22

A statistical method of Estimating the concentration of bacteria in a liquid sample

Question 23

95% Confidence Limit?

Answer 23

The True Value will be within the range 95% of the time.

Question 24

Autoclave temp?

Answer 24

121⁰ C

Question 25

What 3 factors do incubators control?

Answer 25

Temperature, humidity, and light

Question 26

Water hardness measures _________, primarily calcium and magnesium.

Answer 26

total dissolved cations in the water

Question 27

What is the preferred number of colonizes on a HPC

Answer 27

30 to 300 CFUs

Question 28

What temp is the agar melted at for a HPC?

Answer 28

45⁰

Question 29

What temperature are TS crucibles dried at?

Answer 29

104⁰

Question 30

What is a heterotrophic organism?

Answer 30

One that uses carbon as a food source.

Question 31

What selective media is used in the Presumptive test?

Answer 31

Laurel Tryptose Broth (LTB)

Question 32

What selective media is used in the Confirmed test?

Answer 32

Brilliant Green Lactose Bile Broth

Question 33

What Selective Media is used in the Completed test?

Answer 33

Plates of Eosin Methylene Blue, then LTB

Question 34

How are test tubes set up initially for the Presumptive test?

Answer 34

Use LTB. Put 10 ml in 5 test tubes, put 1 ml in 5 tubes, and 0.1 ml in 5 test tubes. The 5-5-5 method

Question 35

What information is on the Chain of Custody?

Answer 35

Sampler and Lab: Name, date, time, signature Sample Location Recipients Location Required Analysis and Results

Question 36

What is the Titrant for Total Hardness?

Answer 36

Ethylenediamenetetraacetic acid

Question 37

What pH must a hardness titration be buffered to?

Answer 37

10 pH

Question 38

What is the indicator for a Total Hardness Titration?

Answer 38

ManVer 2 hardness indicator

Question 39

What temperature are coliform incubators set at?

Answer 39

35⁰ C +/- 0.5⁰ C

Question 40

What is a laboratory fortified, or spiked sample, and what does it test for?

Answer 40

A sample with a known quantity of analyte, to test for matrix effects, or if components of a sample matrix interfere with the measurement of the analyze.

Question 41

Solution Concentration =

Answer 41

Instrument result x total volume / sample volume

Question 42

What QC checks for accuracy?

Answer 42

Known check samples

Question 43

What QC checks for precision?

Answer 43

Replicate analysis, the same sample analyzed multiple times

Question 44

What's a replicate sample?

Answer 44

Multiple samples collected at the same sample time

Question 45

What do replicate samples determine?

Answer 45

The precision of all aspects of the analysis

Question 46

Define true value

Answer 46

The known concentration of the analyte of interest in a check sample

Question 47

What's the difference between partial and total alkalinity?

Answer 47

Partial is when all the hydroxide and carbonate are combined with acid and total is when the bicarbonate is all combined with the acid

Question 48

What are the 2 indicators when titrating alkalinity?

Answer 48

Phenolphthalein and Bromcresol Green-Methyl Red