CWEA - LAB ANALYST III with Correct Answers 2024

CWEA - LAB ANALYST III with Correct Answers 2024 What does COLOR measure? - Answer -Amount of color units (CU) in a sample. Color caused by natural metallic ions (Fe & Mg) & industrial wastes. What is the test summary for COLOR? - Answer -Sample -> Tubes -> Compare to color standards over light source Which of the following techniques is used to isolate anionic surfactants (as MBAS) from the sample matrix? - Answer -Extraction In the cyanide determination, which one of the following is not an interference? - Answer -Halogenated aromatics Which of the following is not a major interference in phenol determination? - Answer -Hydroxy derivatives of benzene A freshly prepared sodium hydroxide (NaOH) solution is standardized against primary standard potassium acid phthalate (KHC8H4O4). 0.8000 grams of potassium acid phthalate was dissolved into 50 mL CO2-free water. 2-3 drops of phenolphthalein were added. The sample was titrated to a faint pink endpoint with 22 mLs sodium hydroxide. What is the normality of the sodium hydroxide? - Answer - 0.178 N What does an ICP source consist of? - Answer -A flowing stream of argon gas ionized by an applied radio frequency In gas chromatography, electron capture detectors (ECD) are used to detect which of the following compounds? - Answer -Chlorinated hydrocarbon pesticides Why is methlyene chloride replaced by hexane in sample preparation for analyses detected by GC electron capture detection (ECD)? - Answer -Chlorine compounds are detected by ECD Which of the following methods is used to determine pesticides? - Answer -EPA Method 608 What analysis uses the purge and trap technique? - Answer -Volatile organic compound analysis The test for inhibitory residues on glassware and plastic ware determines the toxic or stimulatory e