Salicylic acid (SA) plays a key role against pathogens of plants and also induces resistance, hence it is an important
signaling compound in plants. SA derivative, such as acetylsalicylic acid (Aspirin®), is widely used and marketed
today as a non steroidal anti-inflammatory drug (NSAIDs) which is one of the first “wonder drugs” of the 20th century.
Here we report a method for quantification of SA and its derivatives i.e. 3,4-dihyroxybenzoic acid (3,4-DHBA), gallic
acid (GA) and gallic acid methyl ester (GAME) obtained from Primulae radix. First, the total polyphenol content (TPC)
of Primulae radix extracts was determined by Folin-Ciocalteu assay. In that context reflux and microwave assisted extracts
(MAE) in different solvents, i.e. water, 100% ethanol, 100% methanol, 50% ethanol and 50% methanol were evaluated.
50% ethanol MAE was taken for the quantitative analysis of SA and its derivatives as the highest amounts of total
polyphenol content were yielded. This extract was pre-concentrated by solid phase extraction (SPE) using Strata-X (surface
modified copolymer of styrene-divinylbenzene) cartridges. Eluted sample was analyzed by a reversed phase liquid
chromatography-electrospray ionization mass spectrometry (RPLC-ESI-MS) system in selected ion monitoring (SIM)
mode. Lower limits of detection (LOD) of 0.74 ng/ml for SA, 1.39 ng/ml for 3,4-DHBA, 3.00 ng/ml for GA and 0.37
ng/ml for GAME and limits of quantification (LOQ) of 2.45 ng/ml for SA, 4.62 ng/ml for 3,4-DHBA, 10.00 ng/ml for GA
and 1.23 ng/ml for GAME were determined. Correlation coefficient values > 0.99 for all standards were obtained. The determined
mean concentrations were 28.80 and 29.34 µg/g for SA, 9.22 and 8.61 µg/g for 3,4-DHBA, 6.17 and 7.12 μg/g
for GA and 0.14 and 0.03 µg/g for GAME using intra and inter-day analyses respectively. Finally, presented data prove
that introduced method is highly sensitive and reproducible for the simultaneous quantification of SA, 3,4-DHBA, GA
and GAME in Primulae radix extract.