英語翻譯
High performance liquid chromatography
HPLC determination was performed with a Shimadzu Model
LC-6A liquid chromatograph supplied with a Reodyne Model
7125 manual injector with a 20-μl loop.The detector was
Shimadzu Model SPD-6A UV spectrometer.The Thermo Separation
Products integrator Model SP 4400 was used for data acquisition
and recording.Prior to use,the eluents were filtrated through
0.45 μm.filters (Sartorius) and degassed under the vacuum.The
column was reversed-phase Hypersil ODS (150×4.6 mm; participle
size 5 μm.) with a Hypersil ODS guard column (Supelco Inc.).
The beer samples were analysed for biogenic amines according to
the modified Geiger method [18].The elution program consisted
of a gradient system with the following solvents:(A) 0.005 M.
ammonium acetate buffer solution adjusted to pH 4.3 with glacial
acetic acid; (B) methanol.After loading the sample,analysis started
with a methanol (B) gradient in buffer A from 65% to 80% for
20 min.and then with isocratic elution of 100% methanol for
10 min.Finally,the column was equilibrated with an isocratic elution
of 65% methanol in buffer A for 10 min.
The flow rate was 1 mL/min.The eluted dansylamines were
detected by monitoring the UV absorbency at 340 nm.
Results
Twenty-seven samples of popular Polish beers were tested
by HPLC method.Eight biogenic amines:monoamines
(TRP,PHM,HIS,TYR),diamines (PUT,CAD),
polyamines (SPD,SPM) and polyamine-derived secondary
metabolites (PRP,PIR) were investigated in the beer
samples.The gradient elution of methanol in ammonium
acetate buffer allowed elution of all the amines in less
than 30 min.In the tested range of biogenic amine concentration
from 0.2 to 10.0 mg/L the correlation coefficient
between peak area and concentration of each standard
amine was higher than 0.99 for every standard
curve.The average recoveries of the amines ranged from
81.6% to 104.1% with the lowest value for spermine and
the highest for spermidine.The quantification limits
were established asranged from 0.19 mg/L for spermidine to 0.49 mg/L for2-phenylethylamine three times the detection limit and
and后再加一句ranged from 0.19 mg/L for spermidine to 0.49 mg/L for
2-phenylethylamine.