Detection of silver protein complex injections in the bovine udder using X-ray fluorescence: a preliminary investigation.

To determine the feasibility of using x-ray fluorescence (XRF) to detect the presence of silver in the mammary gland of dairy cows injected with mild silver protein suspension. The XRF spectroscopy was conducted on cadaver udders with and without mild silver protein injected. Spectral analysis was performed in order to determine the amplitude of the silver K-alpha peak that was detected. By comparing the amplitude of the K-alpha peak to the background, a minimum time of collection was determined, as a measure of the time required to observe a silver signal that is significantly non-zero. The minimum detection time required for evidence of injected silver suspension was calculated to be 2.8 +/- 0.2 s. Even with an additional requirement that the net signal exceed 50 counts, the clear indication of the presence of silver will be observed within 4 min of interrogation. X-ray fluorescence spectroscopy was shown to be a viable method for the detection of injected silver protein in cadaver mammary glands of dairy cows. While these findings are promising, further studies must be conducted to investigate the time dependence of the silver signal when diffusion, absorption, and redistribution are involved, under conditions that better mimic those encountered at an exhibition. This technique, used in conjunction with screening ultrasound examinations, has the potential to confirm sites of injection of silver compounds.