DETERMINATION OF LOW NANOGRAM MILLILITRE LEVELS OF VOLATILE ORGANIC-COMPOUNDS IN ON-PURPOSE AND BY-PRODUCT HYDROCHLORIC ACIDS/

Hydrochloric acid (HCl) is used in the food industry as a processing a id in the manufacture of certain foods. HCl is manufactured, either di rectly from inorganic sources, i.e. 'on-purpose' or indirectly as a by -product from the production of organic compounds generally intended f or non-food applications. By-product HCl potentially may contain trace s of the manufactured product, its precursors, and other reaction by-p roducts. Many of the potential contaminants are volatile organic compo unds (VOCs) such as vinyl chloride and benzene. A study was conducted to determine whether there were differences between the levels of VOCs found in HCl samples collected from two on-purpose HCl manufacturers and two by-product HCl manufacturers. Process water used to manufactur e the HCl also was analysed. Twenty-nine VOCs were determined by purge -and-trap concentration and capillary gas chromatography/mass spectrom etry. Of these, nine were found in the process water and in both the b y-product and on-purpose HCl samples at total VOC levels of less than 116 ng/ml. The levels of total VOCs identified in the two on-purpose H Cl samples were 58 and 80 ng/ml; the levels of total VOCs identified i n the two by-product samples were 41 and 115 ng/ml. The process water appeared to be the source of most of the contaminants. These results s how that the levels of VOCs found in the two types of acid are compara ble.