[2] [2] Sarkar A, Alamelu D-Aggarwal S K. Optics and Laser Technology, 2012, 1(44): 30.

[3] [3] Ermalitskaia F E, Voropay Y S, Zajogin A P. Journal of Applied Spectroscopy, 2012, 77(2): 153.

[4] [4] Gondal M A, Dastageer A, Maslehuddin M, et al. Optics and Laser Technology, 2012, 3(44): 566.

[5] [5] Haider A F, Khan Z H. Optics & Laser Technology, 2012, 6(44): 1654.

[6] [6] Elsayed K, Imam H, Harfoosh A, et al. Optics and Laser Technology, 2012, 1(44): 130.

[7] [7] Zhang J, Ma H H, Xi J H, et al. Journal of Analytical Atomic Spectrometry, 2012, 27: 1903.

[8] [8] Sabsabi M, CIelo P. Applied Spectroscopy, 1995, 49, (4): 499.

[9] [9] Aragon C, Aguilera J A, Penalba F. Applied Spectrosc., 1999, 53: 1259.

[10] [10] Sabsabi M, Cielo P. Applied Spectroscopy, 1995, 49(4): 499.

[11] [11] Sherbini A M, Aamer A A. Scientific Research, 2012, 3: 502.

[12] [12] Andrey M P, Francesco C, Roberta F. Journal of Analytical Atomic Spectromery, 2009, 24: 602.

[13] [13] Ahmed A I, Khalil A I. Optical & Laser Technology, 2013, 45: 443.

[15] [15] Griem H R. Plasma Spectroscopy. New York: McGraw-Hill, 1964: 375.

[16] [16] Ashraf M E, Abdel A S. Scientific Research, 2012, 2: 278.