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Underivatized Amino Acids Analysis in Baby Formula on Raptor Polar X

LC_FF0579
PeakstR (min)Precursor IonProduct Ion
1.Tryptophan1.17205.07146.08
2.Phenylalanine1.26166.13120.10
3.Leucine1.41132.1386.10
4.Isoleucine1.55132.1386.10
5.Methionine1.62150.07104.10
6.Tyrosine1.69182.10136.08
7.Taurine1.91126.07108.07
8.Valine1.98118.1372.11
9.Proline2.29116.1370.09
10.Alanine3.0090.0344.10
PeakstR (min)Precursor IonProduct Ion
11.Threonine3.12120.1374.08
12.Glycine3.6276.1030.11
13.Glutamine3.87147.1384.07
14.Serine3.93106.0760.09
15.Asparagine4.08133.1374.07
16.Arginine4.47175.1770.09
17.Histidine4.66156.07110.16
18.Lysine4.97147.1384.13
19.Glutamic acid5.89148.1084.10
20.Cystine6.10241.13152.00
21.Aspartic acid7.12134.0774.06
ColumnRaptor Polar X (cat.# 9311A12)
Dimensions:100 mm x 2.1 mm ID
Particle Size:2.7 µm
Temp.:30 °C
Standard/Sample
Diluent:20:80 Water:acetonitrile, 0.01 N HCl
Conc.: Endogenous amino acids
Inj. Vol.:5 µL
Mobile Phase
A:Water, 0.5% formic acid
B:Mobile Phase B: 9:1 Acetonitrile:20 mM ammonium formate in water (pH 3.0) (The ammonium formate concentration is 20 mM relative to the total volume of mobile phase B. See preparation notes for instructions on diluting a 200 mM aqueous starting solution.)
Time (min)Flow (mL/min)%A%B
0.000.51288
3.500.51288
8.000.57030
8.010.51288
10.00.51288
DetectorMS/MS
Ion Mode:ESI+
Mode:MRM
InstrumentUHPLC
Sample PreparationA 200 µL aliquot of protein hydrolysate formula (Similac ALIMENTUM) was mixed with 800 µL of acetonitrile and 10 µL of 1 N HCl. After centrifugation at 4000 rpm for 5 minutes, the supernatant was diluted 20-fold with 20:80 water:acetonitrile (0.01 N HCl) and injected for analysis.
NotesMobile Phase B Preparation: To make 500 mL of mobile phase B, measure ~45 mL of water into a small beaker and add 1 mL of 10 M ammonium formate solution. Adjust pH to 3.0 by adding formic acid and then bring the volume to 50 mL with water. Combine this 50 mL ammonium formate solution (pH 3.0) with 450 mL of acetonitrile to complete the preparation.