Nontargeted NMR Analysis To Rapidly Detect Hazardous Substances in Alcoholic Beverages

Abstract

Nuclear magnetic resonance spectroscopy is introduced for the analysis of alcoholic beverages in the context of governmental health and safety control. For sample preparation of all types of alcoholic beverages, only addition of buffer is required as single step. To detect potentially unsafe samples especially in the context of unrecorded alcohol (i.e., illegally or informally produced alcohol), a nontargeted approach based on principal component analysis (PCA) was applied. The PCA scores plot of 304 samples clearly shows seven conspicuous samples with highly divergent scores from the rest of the samples. These samples contained hazardous substances such as diethyl phthalate or polyhexamethyleneguanidine, as well as extremely high concentrations of methanol or ethyl carbamate. In addition to the nontargeted approach, partial least squares regression allowed us to quantify several parameters such as methanol, higher alcohols, 2-phenyl alcohol and ethyl acetate with high correlation to gas chromatographic reference analysis (R 2 = 0.92-0.98).

Improved classification of fused data: Synergetic effect of partial least squares discriminant analysis (PLS-DA) and common components and specific weights analysis (CCSWA) combination as applied to tomato profiles (NMR, IR and IRMS)

“…For example, PCA and cluster analysis are often applied to detect outliers and for exploratory analysis of the data [36][37][38][39]. Based on this preliminary investigation, it can be decided if the application of more advanced multivariate approaches aiming at discrimination or prediction of analytical parameters is reasonable.…”

Investigation into the structural composition of hydroalcoholic solutions as basis for the development of multiple suppression pulse sequences for NMR measurement of alcoholic beverages

“…After application of two dummy scans, 128 scans were collected into a time domain of 131 072 (131 K) complex data points using a 20.5503 ppm spectral width and a receiver gain of 101. The acquisition time was set to 7.96917 s and the recycle delay was 4 s. Sample preparation and acquisition parameters for 1 H NMR measurements of alcoholic beverages were detailed in the previous publications . The NMR data were acquired automatically under the control of ICON‐NMR (Bruker Biospin, Rheinstetten, Germany).…”

Rapid detection of toxic compounds in tobacco smoke condensates using high-resolution 1H-nuclear magnetic resonance spectroscopy

“…For example, it has been successfully used to detect unknown contaminants in potable water, 36 carbonated 37 and alcoholic 38,39 beverages. In particular, Charlton et al 36 demonstrated that NMR spectroscopy is an ideal technique for the non-targeted detection of unknown contaminants, showing that mixtures of pesticides, industrial solvents, toxins and explosives could be identied under the same experimental conditions.…”