481 / 670
5
(t) LC vials, Thermo Scientific, Sydney, Australia
(u) SDBͲL cartridges 200 mg/3 mL, Phenomenex, Sydney, Australia
(v) UPLC system (Thermo Accela, (ThermoͲScientific, San Jose, CA)).
(w) ReversedͲphase LC column: Catalogue no.186003536, ACQUITY UPLC HSS T3 1.8ʅm
1.0 x 100mm (Waters, Milford, MA)
(x) PreͲcolumn: Catalogue no.186003976, ACQUITY HSS T3 1.8ʅM VANGUARD
(y) Column heater at 30
o
C
(z) Thermo Pal HTC autoͲsampler
Thermostat at 10
o
C
Injection loop 20 μL
(aa)
Tandem quadrupole MS (TSQ Quantum AccessThermoͲScientific)
C. Reagents
(a) K
2
HPO
4
(Univar, AjaxͲFinechem, Sydney, Australia)
(b) KH
2
PO
4
(Univar, AjaxͲFinechem, Sydney, Australia)
(c) Orthophosphoric acid (Univar, AjaxͲFinechem, Sydney, Australia)
(d) KOH (Univar, AjaxͲFinechem, Sydney, Australia)
(e) LͲascorbic acid (SigmaͲAldrich, Sydney, Australia)
(f) 2,3 diͲmercaptoͲ1Ͳpropanol (SigmaͲAldrich, Sydney, Australia)
(g) Standard folic acid and 5Ͳmethyltetrahydrofolate (Schircks Laboratories, Jona,
Switzerland).
(h) Stable isotope labelled (
13
C
5
) folic acid and (
13
C
5
) 5Ͳmethyltetrahydrofolate (MerckͲ
Eprova, Schaffhausen, Switzerland)
(i) Hydrochloric acid 32 % (10.2 M) (Univar, AjaxͲ Finechem, Sydney, Australia)
(j) HPLC grade acetonitrile (Univar, AjaxͲ Finechem, Sydney, Australia)
(k) HPLC grade formic acid (Univar, AjaxͲ Finechem, Sydney, Australia).
(l) Purified MilliͲQ water (
d
0.1
P
S/cm) (Millipore, Bedford, MA).
Fol-20 (February 2016)
FOR ERP USE ONLY
DO NOT DISTRIBUTE