0121-4004 0121-4004 S0121-40042006000200003 Colombia 00 00 2006 00 00 2006 13 2 21 25

1 2004 11 2 2 18-8 2 2001 5 7 7 451-6 3 1984 4 2004 1 14 14 121-8 5 2000 6 1996 27 229-240 7 2005 12 1 1 15-7 8 2000 10 491-9 9 2002 52 99-20 10 2000 293-312 11 2002 62 1 1 231-4 12 2000 10 3 3 501-5 13 Association of Official Analytical Chemist 1980 14 2000 15 2000 16 2000 17 1997 62 363-3 18 1995 30 1 1 35- 3 19 1995 30 1 1 18-4