Page:NIOSH Manual of Analytical Methods - 5040.pdf/2

 ELEMENTAL CARBON (DIESEL PARTICULATE): METHOD 5040, Issue 3, dated 15 March 2003 - Page 2 of 5 REAGENTS:

EQUIPMENT:

1. A qu eo us so lu tio ns of re ag en t g ra de (99+ % ) sucrose, 0.1 to 3 mg C per m L solution. Ensure filter spike loading range brackets that of samples. 2. Ultra pure H 20, Type I, or equiva lent. 3. UHP helium (99.999%), scrubber also required for removal of oxygen. 4. Hydrogen, purified (99.995%), cylinder or hydrogen generator source. 5. Ultra Zero air (low hydrocarbon). 6. 10% oxygen in helium balance, both gases UHP, certified mix. 7. 5% m ethane in helium balance, both gases UHP, certified mix.

1. Sam pler: Quartz-fiber filter, precleaned (in low temperature asher 2 to 3 h, or muffle furnace for 1 to 2 h at ~ 800 °C), 37-mm, in a 3-piece cassette with filter support (stainless steel screen, cellulose pad, or a second quartz filter). Altern ative sam plers m ay be requ ired in dusty environments. See ref. [2] for details. NOT E 1: High purity, high efficiency, binderfree quartz-fiber filters must be used (e.g., Pall Gelman Sciences Pallflex Tissue qua rtz 250 0Q AT -UP . Precleaned filters are available from several laboratories. Filters also can be p urchas ed a nd c leaned in-hou se. Filte rs should be cleaned in a m uffle furnace operated at 800-900 oC for 12 ho urs. Che ck (ana lyze) filters to ens ure rem oval of OC conta m inants. A shorter cleaning period may be effective. O C res ults im m ediate ly after clean ing sh ould be below 0.1 µg/cm 2. OC vap ors readily adsorb onto clean filters. Even when stored in closed containers, OC loadings may range from 0.5 µg/cm 2 after several weeks. NOT E 2: Cellulose supports give higher O C blanks than screen s an d qu artz filters. Bottom quartz filters can be used to correc t for adsorbed vap or; see ref. [2]. 2. Personal sampling pump with flexible tubing. 3. Th erm al-optical analyzer; se e ref. [2]. 4. Metal punch for removal of 1.5 cm 2 rectangular portion of filter. NOTE: A sm aller portion (e.g., taken with cork borer) may be used, but the area must be large enough to accomm odate the entire laser beam (i.e., be am should pass through the sample, not around it). The area of the portion must be accurately k nown, and the sam ple must be carefully positioned (the filter transmittance will decrease dram atic ally when the sam ple is properly aligned). A filter portion $0.5 cm 2 with diameter or width # 1 cm is recomm ended. 5. Syringe, 10-:L. 6. Alum inum foil. 7. Needle (for lifting filter punch portion). 8. Forceps 9. Volumetric flasks, Class A. 10. Analytical balance.

NIOSH Manual of Analytical Methods (NMAM), Fourth Edition