嘉磷塞[glyphoste, N-(phosphonomethyl)glycine]在薄膜狀態下及在水溶液中，以波長254nm之紫外燈在距離10公分處照射72小時，其主要光分解產物是AMPA[(aminomethyl)phosphonic acid]。其半衰期均約為8小時，但8小時以後，在水溶液中比在薄膜狀態下之分解更為快速。在水溶液中置於黑暗下72小時，有25.8%之嘉磷塞分解。在pH為7之中性環境中嘉磷塞顯得很安定，在72小時後，未分解之嘉磷塞達86.5%以上。溶液中之酸鹼度明顯的影響光分解作用，在pH為4之酸性狀態及pH為10之鹼性狀態下，經過72小時之紫外光照射，其未分解之嘉磷塞分別為44.8%及56.2%。

Glyphosate[N-(phosphonomethyl)glycine]was irradiated under the UV-light at 251 nm from a distance of 10 cm. in a thin film as a solid state and in the aqueous solution for 72 hr. the major photodegradation product was AMPA [(aminomethyl)phos-phonic acid]. The half life was about 8 hr, both in solid state and in aueous solution. After 8 hr. degradation rate was more rapid with an aqueous solution than that in the solid state. In the aqueous solution. 25.8% of glyphosate decomposed in dark for 72 hr. Glyphosate was relatively stable when it was kept neutral at pH 7. 86.5% of this herbicide remained unchanged at 72 hr. The effect of pH apparently gave a great influence for the photodegradation. At the acid state at pH 4. the unchanged glyphosate was 44.8%. and in the alkaline state at pH 10. it was 56.2% under UV-light for 72 hr.