Both the methods differed non significantly when calcium was added at a concentration of 534 mg per litre milk samples. In case of mixed milk, the calcium concentration of control milk was 1,576 and 1,565 ppm which proportionately increased to 2,258 and 2,203 ppm for neutralized milk (with added calcium of 648 mg per litre), respectively using DD HNO3 and DD HCl methods.