22 element speciation

Question 1

What is a chemical species?

Answer 1

It is a specific form of an element that is defined by isotopic composition, electronic or oxidation state, complex or molecular structure

Question 2

Define speciation analysis

Answer 2

Analytical activity of identifying and/or measuring the quantities of one or more individual chemical species in a sample

Question 3

COmpare species-specific and species unspecific IDMS

Answer 3

Species-specific:
sample is spiked before sample preparation
results not affected by analyte losses (Adv)
analysis of single species (LIm)
need to know the species that u want to quantify (Lim)

Species-unspecific
sample is spiked with species-unspecific spike after sample preparation
compensates only for species conversion resulting from instrumental analysis
analysis of multiple species
no need to know the species that u want to quantify

Question 4

Describe the spike preparation needed for SS-IDMS.

Answer 4

ferritin gene inserted into a plasmid
E.coli can produce ferritin
Destroy bacteria to isolate ferritin

Question 5

Describe Gel electrophoresis

Answer 5

protein mixture is loaded into small wells in a gel plate
voltage is applied
small molecules interact less well with the gel and run faster. Hence, separation.

2D
proteins are separated in one direction by mass
turn the plate 90 degrees and separate the proteins by their isoelectronic point using a pH gradient

Question 6

Describe Laser Ablation ICP-MS

Answer 6

laser focused by a prism to sample.

Ablate a particular spot and the sample goes into tubing and gets ionized.