Determination of food contamination by mineral oil from jute sacks using coupled LC-GC.

Jute fibers are treated with about 5-7% of a high boiling mineral oil fraction ("batching oil") to render them flexible for making fabrics. Foods transported in jute bags are contaminated by this batching oil. A method involving automated on-line LC-GC is described for determining these hydrocarbons in various foods. Complete transfer of the LC fraction to GC is presupposed for obtaining the required sensitivity. Results are given for nuts, coffee, cocoa products, and rice. Contamination ranged between about 5 and 500 ppm.