Potential safety concerns of volatile constituents released from coffee-ground-blended single-use biodegradable drinking straws: A chemical space perspective.

Incorporating spent coffee grounds into single-use drinking straws for enhanced biodegradability also raises safety concerns due to increased chemical complexity. Here, volatile organic compounds (VOCs) present in coffee ground straws (CGS), polylactic acid straws (PLAS), and polypropylene straws (PPS) were characterized using headspace - solid-phase microextraction and migration assays, by which 430 and 153 VOCs of 10 chemical categories were identified by gas chromatography - mass spectrometry, respectively. Further, the VOCs were assessed for potential genetic toxicity by quantitative structure-activity relationship profiling and estimated daily intake (EDI) calculation, revealing that the VOCs identified in the CGS generally triggered the most structural alerts of genetic toxicity, and the EDIs of 37.9% of which exceeded the threshold of 0.15 µg person-1 d-1, also outnumbering that of the PLAS and PPS. Finally, 14 VOCs were prioritized due to their definite hazards, and generally higher EDIs or detection frequencies in the CGS. Meanwhile, the probability of producing safer CGS was also illustrated. Moreover, it was uncovered by chemical space that the VOCs with higher risk potentials tended to gather in the region defined by the molecular descriptor related to electronegativity or octanol/water partition coefficient. Our results provided valuable references to improve the chemical safety of the CGS, to promote consumer health, and to advance the sustainable development of food contact materials.

Non-target screening of (semi-)volatiles in food-grade polymers by comparison of atmospheric pressure gas chromatography quadrupole time-of-flight and electron ionization mass spectrometry.

Atmospheric pressure gas chromatography (APGC) coupled to quadrupole time-of-flight (QTOF) and electron ionization mass spectrometry together with commercial library search are two complementary techniques for non-target screening of volatile and semi-volatile compounds. Optimization was first conducted to achieve easier search of correspondent peaks between the two systems. Analytical strategy for the determination of volatile and semi-volatile compound with different identification confidence levels was then proposed and applied to food contact grade polypropylene (PP) samples. Identification was found to be much easier and less time-consuming especially when correspondent peak was found in the two systems with the help of library search, exact mass of precursor and fragment ions as well as Kovats Index (KI). The behavior of APGC-QTOF-MS was also further investigated. Apart from the M+. ion and the well-known adduct [M+H]+ others such as [M-3H + O]+, [M-3H+2O]+ and [M-H+3O]+ were also observed for n-alkanes. Besides, new reaction products were found, formed by diol compounds (1-Monostearoylglycerol, 2-Monostearoylglycerol and NX 8000K) and silanediol dimethyl, which would be a transformation product of the silicone base septum or the methyl 5% phenyl polysiloxane based column. These new compounds were only detected in APGC-MS-QTOF as EI-GC-MS was not enough sensitive for this purpose.

[Determination of organochlorine pesticide residue in nine Chinese herbs by gas chromatography].

OBJECTIVE: To determine organochlorine pesticide residue in 9 Chinese herbs. METHODS: The organochlorine pesticides were extracted from the herbs with mixed solvents of n-hexane and acetone by a solid-phase extraction cartridge Florisil. Capillary gas chromatography was used to separate the samples. RESULTS: Good linearities were obtained for 11 organochlorine pesticides. The average recoveries at two concentration levels ranged from 79.9% to 89.0%,and from 86.3% to 104.8%, with relative standard deviations of 1.8% to 7.1%, respectively and detection limit of 2 g/kg. The residues of the organic pesticides exceeded national standard in Pogostemon cablin and Panax notoginseng. CONCLUSION: Capillary gas chromatography combined with electron capture detection provides a practical means for detecting organic pesticide residue in Chinese herbal medicines, and the limits of pesticide residues should be formulated in Chinese pharmacopoeia.