Abstract:Gold is a strategically critical and precious metal, and its accurate determination is crucial for mineral resource exploration and evaluation. However, the analysis of gold faces significant challenges due to its extremely low abundance, complex occurrence states, and interference from various coexisting components. Traditional high-temperature roasting, a key pretreatment step for removing interferents such as arsenic, sulfur, and carbon, involves complex procedures and is susceptible to sample matrix and roasting temperature, often leading to incomplete decomposition or sample sintering. Particularly in antimony-bearing minerals, residual antimony after roasting tends to hydrolyze during acid digestion, forming precipitates that can encapsulate or adsorb gold, resulting in significantly low determination results. This study replaces high-temperature roasting with potassium chlorate pretreatment to eliminate interference from carbonaceous matter and sulfides. A novel bromine water–sodium chloride–hydrobromic acid system was employed to efficiently dissolve gold while simultaneously removing antimony through volatilization. Gold was then enriched using thiourea-loaded foam and determined by atomic absorption spectrometry, achieving accurate analysis of gold in complex ores. The research established that pretreating samples with 2g potassium chlorate and 20mL nitric acid completely oxidizes interfering components like carbon and sulfur. Through systematic optimization, the optimal gold dissolution conditions were determined: using 40mL of a mixed solvent containing 1.0% (v/v) Br?-H?O and 3.0% (w/v) NaCl, along with 15mL hydrobromic acid, for a reaction time of 30 minutes. This protocol achieves efficient gold dissolution and simultaneous antimony volatilization. Enrichment experiments demonstrated that polyurethane foam loaded with thiourea is significantly superior to ordinary foam for gold preconcentration. Under the optimal conditions, the method achieves a detection limit of 0.021 μg/g. Analysis of the antimony ore certified reference material GBW07174 yielded results consistent with certified values. The method precision (RSD) ranged from 1.47% to 2.67%, and accuracy (RE) from 0.32% to 5.29%, with all indicators complying with the requirements of the DZ/T 0130-2006 specification. This method exhibits good selectivity, high accuracy, and operational simplicity, making it suitable for the accurate determination of gold in high-antimony and other complex matrix ores.