Fingerprinting of propolis by easy ambient sonic-spray ionization mass spectrometry

Abstract

a b s t r a c tChemical profiles of a representative set of 49 propolis ethanolic extracts collected worldwide (North and South America, Europe, Asia and Oceania) were obtained via easy ambient sonic-spray ionization mass spectrometry (EASI-MS). This simple and easily implemented fingerprinting technique analyses directly (without any pre-separation or sample manipulation) a tiny droplet of the ethanolic extract placed on a inert surface under ambient conditions. Data acquisition took about a minute per sample with no substantial sample carry-over. Extraction of propolis with ethanol by using an ultrasonic bath method gave EASI-MS data similar to the traditional maceration method, reducing total analysis time for the crude propolis resin from a week to just ca 1 h. Principal component analysis of the EASI-MS data is shown to group samples according to the plant sources of their resins, which characterizes their geographical origin.

Analytical methods applied to diverse types of Brazilian propolis

“…This method was applied to 49 samples of Apis and stingless bee propolis from the Americas, Europe, Asia, the Middle East and Australia [48]. The EASI-MS negative ion mode fingerprints were found to be quite similar to the ESI(-)-MS of the same samples and the PCA grouping of the fingerprints correlated well with those in previous studies [25,45].…”

Mass spectrometry made easy: The quest for simplicity

“…EASI and its sister techniques have been used in a variety of applications; for (1) the direct analysis of drug, pills as exemplified for sildenafil (Figure a), and for the characterization of TLC spots, as exemplified for cocaine (Figure b), for the quality control and certification of geographical origin of olive oils; for direct fingerprinting control of forgery in perfumes; for the nearly instantaneous characterization of the composition of cationic surfactants and quality control of fabric softeners; for the analysis of biodiesel and biodiesel/petrodiesel blends in combination with high performance thin layer chromatography; for fingerprinting analysis of propolis; for the direct analysis of fuels; for the instantaneous characterization of vegetable oils via TAG and FFA profiles, in combination with selective sequesters based on molecularly imprinted polymers (MIP) for the analysis of phenothiazines in urine (Figure d); for the fingerprinting and aging of ink in forensic investigations; as a rapid and secure screening method for street illegal drugs; to characterize noble and endangered woods; for the direct monitoring of known and unknown (or unexpected) drug degradation products as a function of time and manufacturing process, as exemplified for enalapril maleate (Figure c), via thermal imprinting for the analysis of TAG profiles in meat matrices; for petroleomic studies of ‘untouched’ crude oil samples; for the forensic investigation of counterfeit money bills; and, in its Venturi version, for real‐time analysis of brain tissue . These are illustrative of the ‘whole world’ (see cover picture) application of modern ‘simpler’ MS.…”

Monitoring binding affinity between drug and α1-acid glycoprotein in real time by Venturi easy ambient sonic-spray ionization mass spectrometry

“…V-EASI-MS is also a type of ambient ionization technique, as the samples are analyzed during the reaction process without ultrafiltration, washing, or displacement. Without electrical syringe pumping, the samples are extracted by the Venturi effect [20,21], it gives the possibility of directly visualizing the binding reaction and becoming an ideal method for real time online analysis. To the best of our knowledge, few method has been reported for measuring drug-AGP binding affinity in real time.…”