| 摘要 |
<p>The residual oil and/or the oil content in effluents of grease separators, metal cleaning liquor and other industrial wastes is checked by extracting a sample with a readily volatile solvent. The extract is freed from solvent at a temp. below the b. pt. of the solvent in a dish, lined with an optically and chemically inert non-hygroscopic gel and an added fluorescene indicator. The dried out mass is exposed to short-or long-wave ultraviolet light and compared against a reference sample for fluorescence intensity differences. This system is applicable to a very wide range from 0.1 to 1000 mg litre in aq. phase and is extremely rapid. The usual two days delay for conventional methods is saved.</p> |
