Please answer the following questions as completely and concisely as possible. Y

ID: 1004523 • Letter: P

Question

Please answer the following questions as completely and concisely as possible. You must show all of your work to receive full credit. Only use activities if the question explicitly asks for them! Tables can be found on the last sheet of your exam. Good luck! 1. Briefly describe the difference between the detection limit and the quantitation limit. (10 points) The Aetace son Mstr The avantitat on l mit is what the Mac 2. Imagine that solid lead (ll) sulfide (Pbs) was accidentally spilled in a fresh water lake and an ocean. Would the concentration of toxic Pb? ions be higher in the lake or the ocean? WHY? (5 points) 1 rer ne There are

Explanation / Answer

Limit of detection

(LoD)

Limit of quantitation

(LoQ)

LoD is the lowest analyte concentration which can be reliably analysed and distinguished from zero or Limit of Blank(LoB)

LoQ is the lowest amount of analyte in a sample which can be quantitatively determined with suitable precision and accuracy.

LoD is very low concentrations of the analyte

LoQ may be equivalent to or much higher than LoD

LoD is important and is used for the tests used to distinguish between the presence or absence of an analyte (e.g. drugs, troponin, human chorionic gonadotrophin)

LoQ is used to reliably measure low levels of hormones (e.g. TSH) for clinical diagnosis and management