Phosphate Furnace Slag vs. Limestone, A 10-Year Lysimeter Study of Soil Liming

Colorimetric Determination of Fluorine in Waters and Soil Extracts

“…These include gravimetric (3, 4, 7, 12, 16, 21), iodometric (5), Kjeldahl (17,18), acidimetric (1), and electrometric (18) methods. To date no spectrophotometric methods for the determination of caffeine and theobromine in cocoa samples have been presented, although they have been determined spectrophotometrically in other products (8,10). The absorption peaks of high intensity exhibited by theobromine and caffeine in the ultraviolet region (Figure 1) suggested their use as a basis for a very sensitive method for their determination in cocoa samples.…”

“…expeditious than the distillation and titration procedure of Willard and Winter (19), which is prescribed by the Association of Official Agricultural Chemists for fluorine in water (S). At this station the Sanchis procedure (13) has been employed for the determination of fluorine carried by rainwater leachings from added fluoric materials and phosphate furnace slag in lysimeter experiments (8)(9)(10). In the course of these determinations, a number of simplifications were introduced and checked against the original.…”