1,4-Dihydroxynaphthalene,neat,neat,100mg

Nitrate as NO3-, 1000µg/ml in water, 100ml

2,2',6,6'-Tetrachloro[13C12]biphenyl, 1.2ml x 50ug/ml, nonane

Sulfur Calibration Mixtures: Di-n-butyl sulfide in Heavy White Oil (less than 20mg/kg S) Unit : 10mL screw-capped bottle Light White Mineral Oil Heavy White Mineral Oil (20 cSt at 40°C) (70 cSt at 40°C)