Broderick G A, Kang J H
J Dairy Sci. 1980 Jan;63(1):64-75. doi: 10.3168/jds.S0022-0302(80)82888-8.
Catalyzed phenol-hypochlorite and ninhydrin colorimetric procedures were adapted to the Technicon AutoAnalyzer for simultaneous determination of ammonia and total amino acids in ruminal fluid or ruminal in vitro media. The manifold developed was compatible with a sampling rate of 40/h without significant sample-to-sample carryover. With proper storage, reagents for both the phenol-hypochlorite and the air-stable ninhydrin systems were stable for 8 mo or more. Response of individual amino acids in the phenol-hypochlorite system were generally 1% or less than equimolar amounts of ammonia. Certain amino acids inhibited ammonia color yield 10 to 15% when with equimolar amounts of ammonia; however, the inhibitory effect of casein amino acids was only 2 to 3%. Although ninhydrin response, relative to leucine, of individual alpha-amino acids ranged from 62 (valine) to 151% (histidine), recoveries of casein amino acids from ruminal fluid had coefficients of variation of 1% or less. Coefficients of variation for ammonia recoveries from ruminal fluid by the phenol-hypochlorite procedure were about half of those for the Conway microdiffusion technique. Intraclass correlations for the adapted procedures indicated high degrees of accuracy and precision for both ammonia and amino acid analyses.
将催化苯酚 - 次氯酸盐和茚三酮比色法应用于Technicon自动分析仪，用于同时测定瘤胃液或瘤胃体外培养基中的氨和总氨基酸。所开发的流路系统能够以每小时40个样本的采样率运行，且样本间的交叉污染不显著。在适当储存条件下，苯酚 - 次氯酸盐和空气稳定的茚三酮系统的试剂可稳定保存8个月或更长时间。在苯酚 - 次氯酸盐系统中，单个氨基酸的响应通常为氨等摩尔量的1%或更低。某些氨基酸与等摩尔量的氨共存时，会使氨的显色量降低10%至15%；然而，酪蛋白氨基酸的抑制作用仅为2%至3%。尽管相对于亮氨酸，单个α - 氨基酸的茚三酮响应范围为62%（缬氨酸）至151%（组氨酸），但从瘤胃液中回收酪蛋白氨基酸的变异系数为1%或更低。通过苯酚 - 次氯酸盐法从瘤胃液中回收氨的变异系数约为康威微量扩散技术的一半。所采用方法的组内相关性表明，氨和氨基酸分析均具有高度的准确性和精密度。
