Majeed, Masar Ibrahem
(2023)
A preliminary study of colorimetric
nanoparticle evaluation of adulterated
Simulated urine for amphetamine-type
stimulants (ATS) abuse testing.
Masters thesis, Universiti Sains Malaysia.
Abstract
Drug abuse is a serious and widespread problem, and urine testing is considered one of the most used methods to detect drug abuse, but as evidenced by the
history of people who have been referred to forensic laboratories, the use of cleaning
powders, bases and their components, birth control pills, or aspirin pills to change Drug
analysis results, because it is believed that these substances will affect the urine
screening test, the purpose of this study is to determine the effect of these substances
on common colorimetric laboratory tests (UDSTs) and to use colorimetric detection of
unmodified gold nanoparticles to detect false negative results.
In this study, a drug screening test strip (commonly performed on urine
samples using immunoassays) will be screened using urine positive for amphetaminetype
stimulants (ATS) and verifying the authenticity of the sample and the presence of
ATS in the sample after addition of counterfeits using thin layer chromatography
method.
A method was used to screen false negative results with less effort and time
than the thin layer chromatography (TLC) method using nanoparticle techniques of
unmodified gold, the effect of eleven common types of adulteration was studied.
Acetic acid, citric acid, hydroxide, hypochlorite based bleach, Pyridinium
chorochromatic PCC, potassium dichromate, sodium chloride, ammonia and nitrate
compounds, eye drops and detergents are the compounds discussed. In four tests, were
tested on urine positive for ATS by adding adulterants at a 2:1 ratio, urine Dipstick
testing and drug presence testing gave negative results for the adulteration cases, and
a third colorimetric test was performed in the urine using TLC method, Marquis reagent, iodoplatins, and Dragendoff reagent. A silica plate was sprayed with a reagent
for the virtual determination of amphetamine, methamphetamine, and 3,4-
methylenedioxy-N-methamphetamine (MDMA) at a temperature higher than 20 °C as
a result, false negative medications can be detected in the urine sample. But this
method requires time, effort and materials, the fourth test is to use a nanoparticle
detector formulated to detect the presence of amphetamine-type stimulants, by
changing the colour from red to blue at a temperature of 24 degrees Celsius, the
nanoparticle detector was able to detect the presence of amphetamine-type stimulants
in low concentrations in urine samples, when compared the use of the TLC
colorimetric detection method with the nanoparticle colorimetric detection method, we
conclude that the latter is superior because it gives results in less time and requires less
effort.
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