S @ 10000 µg/mL in H2O, 100ml

Cr @ 1000 µg/mL in 5% HCl, 100ml

Sulfide (S), 1000µg/mL in Tr. NaOH / Water, 3 x 20ml

Nitrite (NO2-) as N, 1000µg/ml in Water, 100ml