Direct analysis of human breath ammonia using corona discharge ion mobility spectrometry

In this study, ammonia in human breath was directly determined using corona discharge ionization ion mobility spectrometry (CD-IMS) technique with several important advantages including high sensitivity, low cost, high speed, and ease of maintenance. The temperature effect on the ammonia signal was evaluated too. The results indicated that the best temperature for the investigation of breath ammonia was 150 degrees C. The analytical results showed that the linear dynamic range was between 12 and 810 ppb and the detection limit was 6.6 ppb. The relative standard deviation (RSD) was obtained to be 5, 3, and 3 for 290, 348, and 522 ppb, respectively. The amounts of ammonia in breath of eight healthy volunteers were measured. The values were between 236 and 1218 ppb. Also, the inequality in breath ammonia levels was scrutinized over a 6 h working day for three healthy volunteers. The results showed a drop in breath ammonia from the morning amount to the mid-day measurement and then, a progressive increase while the day continued. In addition, the amounts of ammonia were determined to be 1494-1553 ppb in exhaled breath of two renal failure patients. The results obtained in this work revealed that the method was conveniently established without any considerable sample pretreatment for direct analysis of ammonia in human breath. (C) 2013 Elsevier B.V. All rights reserved.