i am using this method because the analyser i am supposed to make use of are not available, but i am afraid i am doing it wrong. help please, and is there is a better way?
Sure, but only water soluble components, like nitrate, sulphate, chloride but as has been said by Jeevan Lal Matawle it depends on the kind of photometer and other facilities at hand. For metals and organics you have to apply other methods. But most importantly, to give a precise answer, it depends on what you are looking for of what you are interested in. Good luck!