Figure7
TheUltra IBD column separates impurities in furosemide.
Figure6
The Allure
™
Basix column retains atenolol without ion pairing agents.
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LC_0072
LC_0071
RestekCorporation • (800)356-1688 • (814)353-1300 •
0
2
4
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12min.
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Diuretics
Another important class of cardiac and high blood pressure
medications are diuretics. These compounds rid the body of
excess fluids and salt (sodium). Diuretics such as furosemide
are used for the management of edema associated with chronic
heart problems. The furosemide molecule contains carboxylic
acid and basic sulfa-amine groups. The zwitterionic nature of
furosemide makes it an ideal candidate for analysis using an
Ultra IBD column (Figure 7).
Enlargement of the baseline reveals that the furosemide
standard is not a pure substance (Figure 7, inset). The impuri-
ties may possibly be a reason why the therapeutic mechanism
of furosemide is not completely understood.
The diuretic admixture of triamterene and hydrochlorothiaz-
ide (HCTZ) is used to remove excess fluid while attempting
to limit the amount of potassium displaced from the body.
The highly-charged HCTZ contains numerous amine and
sulfonic groups. The high charge is the reason it elutes in
Column:
Allure
™
Basix
Catalog #:
9161565
Dimensions:
150 x 4.6mm
Particle Size:
5µm
Pore Size:
60Å
Conditions:
Mobile Phase:
20mM ammonium
acetate pH 4.5:acetonitrile
(20:80, v/v)
Flow:
1.2mL/min.
Temp.:
25.0°C
Det.:
UV @ 225nm
Peak List:
1. uracil (marker)
2. atenolol
Sample:
Inj.:
1µL
Conc.:
1mg/mL
Solvent:
water:methanol
(70:30, v/v)
Column:
Ultra IBD
Catalog #:
9175565
Dimensions:
150 x 4.6mm
Particle Size:
5µm
Pore Size:
100Å
Conditions:
Mobile Phase:
20mM ammonium
acetate pH 4.5:
acetonitrile (70:30, v/v)
Flow:
2.0mL/min.
Temp.:
27.0°C
Det.:
UV @ 280nm
Peak List:
1. uracil (marker)
2. furosemide
Sample:
Inj.:
5µL
Conc.:
1000µg/mL
Solvent:
acetonitrile:water
(60:40, v/v)
Impurities in Furosemide
(enlargement of baseline)
1. uracil
2. furosemide
1
2
0 2 4 6 8 10 12 14min.
0 2 4 6
8 10 12 14 min.
1
2
