Exposure Assessment of Acetamide in Milk, Beef, and Coffee Using Xanthydrol Derivatization and Gas Chromatography/Mass Spectrometry

Abstract

Acetamide has been classified as a possible human carcinogen, but uncertainties exist about its levels in foods. This report presents evidence that thermal decomposition of N-acetylated sugars and amino acids in heated gas chromatograph injectors contributes to artifactual acetamide in milk and beef. An alternative gas chromatography/mass spectrometry protocol based on derivatization of acetamide with 9-xanthydrol was optimized and shown to be free of artifactual acetamide formation. The protocol was validated using a surrogate analyte approach based on d3-acetamide and applied to analyze 23 pasteurized whole milk, 44 raw sirloin beef, and raw milk samples from 14 different cows, and yielded levels about 10-fold lower than those obtained by direct injection without derivatization. The xanthydrol derivatization procedure detected acetamide in every food sample tested at 390 ± 60 ppb in milk, 400 ± 80 ppb in beef, and 39 000 ± 9000 ppb in roasted coffee beans.

Symposium review: Technologies for improving fiber utilization

“…However, acetamide, a co-product of the AFEX treatment produced during cleavage of acetyl groups from hemicellulose (Weimer et al, 1986), is not volatile, rather it can remain with the treated biomass thereby increasing its N content (Bals et al, 2011). Acetamide has been classified as Group 2B possible human carcinogen by the International Agency for Research on Cancer (Vismeh et al, 2018) because of incidences of liver carcinoma during feeding trials in rats (Jackson and Dessau, 1961;Fleischman et al, 1980). Recent studies suggest that ruminal accumulation of acetamide from AFEX treatment is transient and certain ruminal bacteria can grow on the amide (Mor et al, 2019).…”

The food contaminant acetamide is not an in vivo clastogen, aneugen, or mutagen in rodent hematopoietic tissue

“…Acetamide has been investigated as a residue from some pesticides (WHO, 2005), as a solvent with unique properties (Zhang et al, 2012), as an impurity in the manufacture of pharmaceuticals (Snodin, 2011), and as a metabolite of drugs such as phenacetin (Hinson, 1983), metronidazole (Koch et al, 1979) and acetohydroxamic acid (Putcha et al, 1984). However, more recent findings show that acetamide is present throughout the universe from intra-stellar clouds (Hollis et al, 2006) to common foods (Vismeh et al, 2018). Earlier reports indicating that acetamide was present in milk, eggs, and meat have been recently confirmed by Vismeh et al (2018) who surveyed milk and beef samples from different states in the US.…”

“…However, more recent findings show that acetamide is present throughout the universe from intra-stellar clouds (Hollis et al, 2006) to common foods (Vismeh et al, 2018). Earlier reports indicating that acetamide was present in milk, eggs, and meat have been recently confirmed by Vismeh et al (2018) who surveyed milk and beef samples from different states in the US. Wei, 2016 reported the appearance of acetamide in the NMR spectra of roasted chicory roots which was also confirmed by Vismeh et al (2018) who reported the presence of acetamide in roasted coffee beans and instant coffee but not raw coffee beans.…”

Presence of Acetamide in Milk and Beef from Cattle Consuming AFEX-Treated Crop Residues

“…The limit of detection for milk and beef was determined to be 10 and 11 ng/g, respectively, and the limit of quantitation for milk and beef was determined to be 19 and 23 ng/g, respectively. 15…”

“…Previous research suggests that acetamide can pass through the rumen wall 14 and thus may enter the bloodstream. Recently, it has been shown that acetamide is already present as a food contaminant in many foods, including milk, beef, roasted coffee, 15 and chicory root. 16…”