An ion chromatography system employing a low-cost 3D printed absorbance detector for indirect UV detection towards portable phosphate analysis of environmental and industrial waters has been developed. The optical detection cell was fabricated using stereolithography 3D printing of nanocomposite material. Chromatographic analysis and detection of phosphate was carried out using a CS5A 4×250 mm analytical column with indirect UV detection using a 255 nm light emitting diode. Isocratic elution using a 0.6 mM potassium phthalate eluent combined with 1.44 mM sodium bicarbonate was employed at a flow rate of 0.75 ml min-1. A linear calibration range of 0.5 to 30 mg L-1 PO4 3- applicable to environmental and wastewater analysis was achieved. For retention time and peak area repeatability, RSD values were 0.68 % and 4.09 %, respectively. Environmental and wastewater samples were analysed with the optimised ion chromatography platform and the results were compared to values obtained by an accredited ion chromatographer. For the analysis of environmental samples, relative errors of < 14 % were achieved. Recovery analysis was also carried out on both freshwater and wastewater samples and recovery results were within the acceptable range for water analysis using standard ion chromatography methods.