{'fraction_non_alphanumeric': 0.05238970588235294, 'fraction_numerical': 0.04044117647058824, 'mean_word_length': 5.05, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
SIMULTANEOUS DETERMINATION OF IRON AND COPPER BY THIRD-DERIVATIVE SOLID-PHASE SPECTROPHOTOMETRY

ABSTRACT A simultaneous microdetermination of iron and copper at sub-µg/L level by solid phase derivative spectrophotometry has been developed. The compounds TPTZ (2,4,6-tripyridyl-1,3,5-triazine) and Neocuproine (2,9-dimethyl-1,10-phenanthroline hydrochloride), were used as chromogenic reagents to form a blue iron complex and an orange copper complex, respectively (pH = 5.0), which are fixed and concentrated on a cation-exchange resin sephadex sp C-25. The influence of experimental variables on the retention of the complexes on the resin are discussed. The signals in derivative units were measured directly on the solid, packed in a 1 mm spectrophotometric cell. The characteristic amplitude of the signals at 622.0 and 477.0 nm in third-derivative spectra are useful for quantitative determination of iron (0.195–120 ng mL−1; RSD = 1.8%) and copper (0.451–300 ng mL−1; RSD 1.3%). The method was applied to the iron and copper determination in different types of water, respectively.