Detection of low molecular weight adulterants in beverages by direct analysis in real time mass spectrometry

Abstract

Direct Analysis in Real Time Mass Spectrometry (DART-MS) has been used to detect the presence of non-narcotic adulterants in beverages. The non-narcotic adulterants that were examined in this work incorporated a number low molecular weight alcohols, acetone, ammonium hydroxide, and sodium hypochlorite. Analysis of the adulterants was completed by pipetting 1 µL deposits onto glass microcapillaries along with an appropriate dopant species followed by introduction into the DART gas stream. It was found that detection of these compounds in the complex matrices of common beverages (soda, energy drinks, etc.) was simplified through the use of a dopant species to allow for adduct formation with the desired compound(s) of interest. Other parameters that were investigated included DART gas stream temperature, in source collision induced dissociation, ion polarity, and DART needle voltage. Sensitivities of the technique were found to range from 0.001 % volume fraction to 0.1 % volume fraction, comparable to traditional analyses completed using headspace gas chromatography mass spectrometry (HS-GC/MS). Once a method was established using aqueous solutions, , fifteen beverages were spiked with each of the nine adulterants, to simulate real world detection, and in nearly all cases the adulterant could be detected either in pure form, or complexed with the added dopant species. This technique provides a rapid way to directly analyze beverages believed to be contaminated with non-narcotic adulterants at sensitivities similar to or exceeding those of traditional confirmatory analyses.

Applications of direct analysis in real time mass spectrometry in food analysis: A review

“…DART‐MS has been used for the rapid detection of nonnarcotic adulterants such as low‐molecular‐weight alcohols, acetone, ammonium hydroxide, and sodium hypochlorite in beverages (soda, energy drinks, etc. ), 66,67 the screening of trace pesticides in different fruit juices with a lower LOD, 68 the rapid identification and quantification of phthalate plasticizers in beverages at sub‐nanogram per milliliter levels, 69 and phthalate plasticizers in beverages including various juices and tea, 70 and the sensitive and high‐throughput screening of illegally adulterated sulfonylureas in antidiabetic health‐care teas 71 (Figure 3). These studies indicate the suitability of DART‐MS for the rapid quality control analysis of beverages with regard to chemical contamination at sensitivities similar to or exceeding those of traditional confirmatory routines.…”

Determination of ethanol concentration in alcoholic beverages by direct analysis in real time mass spectrometry (DART-MS)

“…Studies have also been completed utilizing DART-MS to analyze beverages for qualitative purposes to identify compounds of interest such as caffeine [17], phthalates [18], and gamma hydro-xybutyric acid (GHB) [19]. While the compounds of interest analyzed by DART-MS are normally higher in molecular weight than ethanol, recent work has highlighted the ability of this tool to detect low molecular weight adulterants, such as ammonia, bleach, methanol, and butanol in beverages [20]. Detection of these compounds, especially methanol, and others, such as iso-amyl alcohol, are crucial for adulteration detection [4].…”

Quantification of adulterants in mezcal by means of FT-MIR and FT-NIR spectroscopy coupled to multivariate analysis

“…Adulteration of alcoholic beverages is an illegal, clandestine, and fraudulent practice that involves different fields: forensics, food safety, and quality control because it can occur at any stage of the elaboration process (Sisco & Dake, 2016). Alcoholic beverages are adulterated by substituting or diluting the original liquid with other of lesser quality like water, ethanol, or methanol.…”