Top Posters
Since Sunday
17
16
s
6
4
m
4
l
3
M
3
j
3
P
3
t
3
S
3
c
3
New Topic  
arealhero arealhero
wrote...
Posts: 7874
7 years ago
An unknown white powder was located at a crime scene. Describe an analytical scheme, in proper order, to identify the drug or drugs which may be present in the powder. For each step, note whether it is a screening or confirmatory test and why it should be used.
Textbook 

Criminalistics: An Introduction to Forensic Science


Edition: 11th
Author:
Read 1295 times
27 Replies
Replies
Answer accepted by topic starter
newstartnewstart
wrote...
Top Poster
Posts: 9404
7 years ago
Sign in or Sign up in seconds to unlock everything for free
More questions for this book are available here
a.   Chromatography, a screening test, can be used to separate the unknown mixtures into its components. This is particularly useful for analyzing drug specimens because drugs may be diluted with practically any material in order to increase the quantity of product available to prospective customers.
b.   Various color tests or UV-Vis spectrophotometry, can be used to as screening tests to presumptively identify which drug or drugs may be present in the powder. This can narrow the scope of substances to be searched for and possibly confirmed in later testing.
c.   IR spectrophotometry or GC/MS analysis are both confirmatory tests with sensitivity and specificity sufficient enough to identify drugs in the powder. GC/MS is most preferred because: (1) it can resolve a highly complex mixture into its components within a brief time period; (2) it is extremely sensitive; and (3) it can yield quantitative results. Connection of the GC/MS unit to a computer further facilitates the comparison of spectra for identifcation purposes.
This verified answer contains over 170 words.
drpepperlover36,  carlisimo2,  Martin Payne,  Wowwww

Related Topics

wrote...
7 years ago
Thx, it's perfect.
wrote...
7 years ago
Welcome Happy Dummy
wrote...
A year ago
thank you
wrote...
A year ago
thank you for this answer, really needed it.
wrote...
A year ago
thank you
wrote...
A year ago
thanks! its perfect!
wrote...
A year ago
perfect!
wrote...
10 months ago
thank you
wrote...
10 months ago
The correct answer is: .
wrote...
10 months ago
thanks
wrote...
8 months ago
Thank you
wrote...
8 months ago
Thanks
  New Topic      
Explore
Post your homework questions and get free online help from our incredible volunteers
  421 People Browsing
 1157 Signed Up Today
Your Opinion
Who's your favorite biologist?
Votes: 137

Previous poll results: Where do you get your textbooks?
Related Images
 629
 155