Increase of methanol in exhaled breath quantified by SIFT-MS following aspartame ingestion

Abstract

Aspartame, methyl-L-α-aspartyl-L-phenylalaninate, is used worldwide as a sweetener in foods and drinks and is considered to be safe at an acceptable daily intake (ADI) of 40 mg per kg of body weight. This compound is completely hydrolyzed in the gastrointestinal tract to aspartic acid, phenylalanine and methanol, each being toxic at high levels. The objective of the present study was to quantify the volatile methanol component in the exhaled breath of ten healthy volunteers following the ingestion of a single ADI dose of aspartame.Direct on-line measurements of methanol concentration were made in the mouth and nose breath exhalations using selected ion flow tube mass spectrometry, SIFT-MS, several times before aspartame ingestion in order to establish individual pre-dose (baseline) levels and then during two hours post-ingestion to track their initial increase and subsequent decrease. The results show that breath methanol concentrations increased in all volunteers by 1082 ±205 parts-per-billion by volume, ppbv, from their pre-ingestion values, which ranged from 193 to 436 parts-per-billion by volume, ppbv, to peak values ranging from 981-1622 ppbv, from which they slowly decreased. These observations agree quantitatively with a predicted increase of 1030 ppbv estimated using a one-compartment model of uniform dilution of the methanol generated from a known amount of aspartame throughout the total body water (including blood). In summary, an ADI dose of aspartame leads to a 3 -6 fold increase of blood methanol concentration above the individual baseline values.2

Metabolic Signatures of Lung Cancer in Sputum and Exhaled Breath Condensate Detected by 1H Magnetic Resonance Spectroscopy: A Feasibility Study

“…Ingested fruits, vegetables, and aspartame can effect the endogenous production of methanol and hence its level of concentration in body fluids. [25][26][27][28] So far, there has not been any previous report explaining the altered metabolism of methanol in malignant cells. Significantly reduced levels of methanol in the breath of lung cancer patients observed in this study and in the study by Bajtarevic et al 24 indicated a possible alteration in its metabolic pathway triggered by the malignant transformation of the normal cells and warrants further investigation.…”

Quantification of Methanol in the Presence of Ethanol by Selected Ion Flow Tube Mass Spectrometry

“…In the absence of ethanol, methanol reacts with H 3 O + to produce the expected protonated product ion CH 3 OH 2 + (m/z 33), along with its monohydrate (m/z 51) and dihydrate (m/z 69). 30 The ions are still produced with ethanol present [illustrated for 5% (v/v) ethanol in Figure 3] but are accompanied by a number of other reaction products deriving (C 2 H 5 OH) 2 (CH 3 OH) (m/z 171) was also the product of an association reaction, with this reaction occurring between the ethanol cluster ion (m/z 139) and methanol. The product ion C 2 H 5 + (C 2 H 5 OH) 2 (CH 3 OH) (m/z 153) is the result of a combination of association and water elimination reactions from the m/z association product.…”

Biochemical Methanol Gas Sensor (MeOH Bio-Sniffer) for Non-Invasive Assessment of Intestinal Flora from Breath Methanol

“…MeOH in exhaled breath has been analyzed by various methodologies, such as gas-liquid chromatography [ 21 ], proton-transfer-reaction mass spectrometry (PTR-MS) [ 20 ], and selected-ion flow-tube mass spectrometry (SIFT-MS) [ 22 , 23 ]. Despite their capability of identifying MeOH in gas mixture, the size and complexity of the system are drawbacks for the on-site MeOH assessment.…”