Neutralizing Aminesin Boiler Steam and Humidified Indoor Air

Objective: The health and comfort of the indoor population have been impacted by the humidity. While people are increasingly spending more time indoors, the presence of pollutants and lack of proper humidification in indoor air have significant risk factors that may lead to multiple health problems. Methods: By applying the right air purification and/or humidification system, the adverse effects of poor indoor air quality can be minimized. Direct steam addition is a common technique to humidify the indoor air of a building. Carbon dioxide or other acidic process contaminants may dissolve in steam or steam condensate that will consequently decrease the pH and make it corrosive for the steam distribution system. To avoid that, neutralizing amines are added to steam that keeps the pH neutral or slightly alkaline(pH 7.5-9.0). However, neutralizing amines have some toxic effects. OSHA, FDA, and NIOSH prescribe maximum concentration limits for them in indoor air. The Central Utility Plant (CUP) of National Institutes of Health (NIH) uses a 50:50 blend of cyclohexylamine and diethylaminoethanol as neutralizing agents for the steam. Results: The CUP at NIH presents the results of monitoring the concentration level of amines through mass balance, online monitoring at specified location of the steam distribution system and field measurement in humidified indoor air at buildings on campus. Conclusion Through theoretical calculation backed up by field measurement, the amine concentration of indoor air is determined to be well below the FDA regulated limits.

Free and bound MCPD and glycidyl esters in smoked and thermally treated fishery products of the German market

To provide a comprehensive overview of the amounts of unesterified and bound 2- and 3-monochloropropanediol (MCPD) and glycidyl esters (G–E) in processed fishery products sold in Germany, an analysis of various frequently consumed products was conducted. In total, 258 commercial samples of breaded and pre-fried fishery products (e.g., frozen fish fingers), fried fish products (e.g., products in marinade), canned fish, smoked fish and some smoked spice preparations were examined. In addition, the effect of different kitchen preparation methods (e.g., baking, frying and roasting) on the MCPD and G–E amounts of fish fingers was studied. The mentioned process contaminants, MCPD and G-E, were quantifiable in the majority of the samples. Although pre-fried and fried fishery products predominantly contained MCPD esters (MCPD-E), mainly free MCPD was found in smoked fish. Compared with other types of smoke generation, hot smoked fish prepared in traditional Altona smoking kilns contained, on average, the highest 3-MCPD contents (range: 12–246 µg/kg). The amounts of bound MCPD in the fried fish products (range for 3-MCPD-E: < LOQ-808 µg/kg) were not significantly different from the amounts in the investigated pre-fried fish samples (range for 3-MCPD-E: < LOQ-792 µg/kg). However, they differ significantly from the amounts in unfried products (< LOQ). After preparation in the kitchen, the contents in the ready-to-eat fish fingers depend primarily on the initial contaminant amounts of the frozen product and/or the frying oil, respectively.

Optimization and Validation of HS-SPME-GC-MS for the Determination of Furan and Alkylfurans in Chocolate-Based Products: Impact of Tempering and Laser Printing

Background Furan and its alkyl substituted (2-methylfuran, 3-methylfuran, 2,3-dimethylfuran, 2,5-dimethylfuran) are found in a range between ppm to sub-ppb levels in many foodstuffs undergoing heat treatments like coffee, chicory, or even chocolate. Objectives Two major objectives are presented. First, we aim at optimizing and validating a HS-SPME-GC-MS method for the quantification of five alkylfurans in chocolate. Second, we focus our study on measuring the quantitative impact of engraving technique on the formation of furan and its derivatives in chocolate, from the raw callets to processed end-products. Method HS-SPME-GC-MS method operating in SIM mode and using isotope dilution technique with deuterated homologue internal standards was used to quantify alkylfurans in chocolate. Results Good repeatability (RSD% = 0.1–8%, in duplicate) and intermediate precision (RSD% = 1.7–7%, n = 6) were obtained for these five process contaminants at 10, 25, and 50 µg/kg. Trueness was varying between 81 and 109%. LoQ ranged from 0.48 to 2.50 µg/kg. Relative expanded measurement uncertainties ranged from 6 to 30%. Finally, tempering is responsible for a 24% increase in furan contamination, while the laser engraving technique results in an additional 31% increase in furan. A similar trend was also observed for 2-methylfuran and 3-methylfuran, whereas no significant increases were observed for 2,3-dimethylfuran and 2,5-dimethylfuran. Conclusions and highlights A reliable and sensitive method of HS-SPME-GC-MS was reported for the first time for the analysis of furan and four alkylfurans in chocolate. This paper demonstrated that engraving using laser-based techniques can increase the levels of these compounds by up to 30%.