Which statement is TRUE regarding BOD and COD sample values?
a. BOD is always greater than or equal to COD b. The same amount of time is required to conduct both analysis c. COD is always greater than or equal to BOD d. None of the above 4. An atomic absorption (AA) instrument is used to determine the presence of ___. a. Metals b. Organics c. Nitrates d. Ammonia 5. Samples for oil and grease analysis may be preserved with ___. a. Phospheric acid b. Nitric acid c. Sulfuric acid or hydrochloric acid d. Sodium hydroxide 6. An important requirement for the collection of groundwater samples for VOC analysis in 40 ml vials is that ___ a. The temperature remains constant b. The temperature remains at -20oF c. The vials are free of air bubbles d. The samples are preserved with ascorbic acid 7. Polynuclear aromatic hydrocarbons (PAH) are classified as ___. a. Semivolatile organic compounds b. Pesticides c. Volatile organic compounds d.