A combined high-performance liquid chromatographic-microbiological assay for serum folic acid.
An assay of folic acid in human serum is described involving HPLC fractionation of deproteinized serum prior to Lactobacillus casei assay. High specific activity [3H]folic acid is added as internal standard to 1 ml serum prior to deproteinization with perchlorate and an aliquot is applied to a C18 reverse-phase HPLC column. The folic acid fraction was assayed by L. casei microtiter plate assay. Intra- and interassay variations (CV) were 5.5 and 7.5% respectively for sera (n = 10) spiked with folic acid. The percentage recovery for folic acid additions of 10 and 20 ng/liter were 105.2 and 103.7%, respectively. The lower limit of detection was 1 ng folic acid/ml serum. Folates other than folic acid and 5-methyltetrahydrofolate were not detected. The assay permitted serial measurements to be made of folates in serum following an oral dose.
Kelly
P
P
Vitamin Research, St James' Hospital, Dublin, 8, Ireland.
McPartlin
J
J
Scott
J
J
D000284:Administration, Oral; D000293:Adolescent; D000328:Adult; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D005492:Folic Acid / Q000097:blood* / Q000493:pharmacokinetics; D006801:Humans; D007780:Lacticaseibacillus casei; D008297:Male
D005492:Folic Acid