Glycerol, Surface tension 63mN/m at 20°C, 30ml

ISO 17495 Internal Standard Stock Solution 2 Internal standards, each 10µg/mL in acetone; unit: 1x5mL 2061.6 2,4-Dibromophenol [615-58-7] 2060.6 2,4,6-Tribromophenol [118-79-6] The following compounds are suggested as alternative I

Nitrite (NO2-) as N, 100µg/ml in Water, 100ml

Bis(3-isopropylphenyl) phenyl phosphate, 1.2ml x 50ug/ml, toluene