Although melamine and cyanuric acid appeared to have low toxicity when administered separately, they induced extensive renal crystal formation when administered together. The subsequent renal failure may be similar to acute uric acid nephropathy in humans, in which crystal spherulites obstruct renal tubules.

We developed a new method to analyze animal feed and feed ingredients for melamine and cyanuric acid. The method is capable of extracting and detecting both melamine and cyanuric acid in a single procedure, whether present as free compounds or bound together as the melamine:cyanurate complex. A novel chromatographic system based on zwitterionic hydrophilic interaction chromatography (ZIC-HILIC) columns enables separation and detection of both compounds in one run. Samples are extracted with a strong aqueous acid which is then diluted to bring the concentration within the working range of the method. The method is applicable over the range of 0.5 to 50 micrograms/gram (microg/g). Samples at higher concentrations may be diluted into this range, which is equivalent to 3.6-360 ng/mL in the injection solvent. Analytes are detected using liquid chromatography/tandem mass spectrometry. The data confirm the presence of both compounds according to criteria recommended by the US FDA Center for Veterinary Medicine. The LC/MS/MS method provides an alternative to derivatization and gas chromatography-mass spectrometry for regulatory analysis of feed samples. Published in 2008 by John Wiley & Sons, Ltd.

The volatile and soil loss profiles of six agricultural pesticides were measured for 20 days following treatment to freshly tilled soil at the Beltsville Agricultural Research Center. The volatile fluxes were determined using the Theoretical Profile Shape (TPS) method. Polyurethane foam plugs were used to collect the gas-phase levels of the pesticides at the TPS-defined critical height above a treated field. Surface-soil (0-8 cm) samples were collected on each day of air sampling. The order of the volatile flux losses was trifluralin > alpha-endosulfan > chlorpyrifos > metolachlor > atrazine > beta-endosulfan. The magnitude of the losses ranged from 14.1% of nominal applied amounts of trifluralin to 2.5% of beta-endosulfan. The daily loss profiles were typical of those observed by others for volatile flux of pesticides from moist soil. Even though heavy rains occurred from the first to third day after treatment, the majority of the losses took place within 4 days of treatment, that is, 59% of the total applied atrazine and metolachlor and >78% of the other pesticides. Soil losses generally followed pseudo-first-order kinetics; however, leaching due to heavy rainfall caused significant errors in these results. The portion of soil losses that were accounted for by the volatile fluxes was ordered as follows: alpha-endosulfan, 34.5%; trifluralin, 26.5%; chlorpyrifos, 23.3%; beta-endosulfan, 14.5%; metolachlor, 12.4%; and atrazine, 7.5%.