7
Figure 13
Ethanolamines on a base-deactivated column.
Figure 11
Organic acids on anUltraAqueous C18
HPLC column.
PeakList:
Conc. (µg/mL)
1. malonic acid
500
2. lactic acid
500
3. acetic acid
1000
4. citric acid
1000
5. succinic acid
2000
6. fumaric acid
10
Sample:
Solvent:
HPLC-gradewater
Inj.:
10µL
Column:
UltraAqueousC18
Catalog #:
9178565
Dimensions: 150 x 4.6mm
Particle size: 5µm
Pore size:
100Å
Conditions:
Mobile phase: 50mM potassium
phosphate, pH 2.5:
acetonitrile (99:1)
Flow:
1.5mL/min.
Temp.:
25°C
Det.:
UV@210nm
LC_0140
1
2
3
4
5
6
0
1
2
3
4
5min.
Figure 12
OrganicAcids on a Stabilwax
®
-DA
column.
Stabilwax
®
-DA, 30m, 0.25mm ID, 0.25µm
(cat.# 11023)
Inj.:
1.0µL split injection (50:1) of a
free acid standard, approximately
10 to 20ng/µLeach analyte
Oven temp.:
145°C
Inj. & det. temp.: 250°C
Carrier gas:
hydrogen
Linear velocity: 40cm/sec.
FID sensitivity:
2 x 10
-11
AFS
GC_CH00280
min. 4
8
12
9
8
7
6
5
4
1
3
2
1. acetic acid
2. propionic acid
3. isobutyric acid
4.
n
-butyric acid
5. isovaleric acid
6.
n
-valeric acid
7. isocaproic acid
8. caproic acid
9. heptanoic acid
Alkalis
Productswith higher pH are useful for
dissolving fatty or oily soils.Alkalis, or
bases, are used to neutralize acidic ingre-
dients, or to raise the pH. Suitable alka-
lis include ethanolamines, ammonium
hydroxide, and sodium silicate. The
more basic compounds, such as
ethanolamines, can be analyzed byGC,
but a base-deactivated column should be
used. Ethanolamines analysis on an
Rtx
®
-5Amine capillaryGC column is
shown in Figure 13.
Antimicrobial Agents
Antimicrobial agents are included in
soaps, detergents, health and skincare
products, and household cleaners. By
controllingmicrobial growth, they con-
trol disease and odor.More than 300
active ingredients currently are used to
control microorganisms.
3
These agents
can be categorized as sterilizers, disin-
fectants, sanitizers, or antiseptics/germi-
cides. Sterilizers are used to eliminate
fungi, viruses, and bacteria; disinfec-
tants, to destroy or control fungi and
bacteria, but not necessarily their spores;
sanitizers, to reducemicroorganisms on
surfaces.Antiseptics or germicides are
used on living people and animals. In the
United States, a product used in or on
the body, or in processed food, is regu-
1
2
3
4
min.
5
10
1. monoethanolamine
2. diethanolamine
3. triethylene glycol monomethylether (IS)
4. triethanolamine
Rtx
®
-5Amine, 15m, 0.25mm ID, 0.50µm
(cat.# 12335)
Inj.:
1.0µL split injection (58:1)
of ethanolamines in
methanol; on-column conc.
34ng each analyte
Oven temp.:
50°C (hold 2min.) to
180°C@10°C/min.
(hold 2min.)
Inj. & det. temp.: 280°C / 300°C
Carrier gas:
hydrogen
Linear velocity: 43cm/sec. set@50°C
FID sensitivity: 6.4 x 10
-11
AFS
GC_CH00296
TheUltraAqueous C18 column is
an excellent choicewhen using
highly aqueousmobile phases.
Embedded polar groups prevent
collapse of the alkyl chains—even
in 100% aqueous environments.
See page 12 formore information.
Website :
E-mail
TelNo : 03 9762 2034 . . . inAUSTRALIA
