{"id":3993,"date":"2025-10-10T16:45:18","date_gmt":"2025-10-10T08:45:18","guid":{"rendered":"https:\/\/www.pgeneral.com\/?p=3993"},"modified":"2025-10-10T16:45:18","modified_gmt":"2025-10-10T08:45:18","slug":"determination-of-chromium-in-refined-sulfur-graphite-furnace-atomic-absorption-spectrometry-2","status":"publish","type":"post","link":"https:\/\/www.pgeneral.com\/ja\/applications\/determination-of-chromium-in-refined-sulfur-graphite-furnace-atomic-absorption-spectrometry-2\/","title":{"rendered":"\u7cbe\u88fd\u786b\u7cbe\u7cbe\u88fd\u786b\u7cbe\u7cbe\u88fd\u786b\u7cbe\u7cbe\u88fd\u786b\u7cbe\u7cbe\u88fd\u786b\u7cbe\u7cbe\u88fd\u786b\u7cbe\u7cbe\u88fd\u7cbe\u88fd\u7cbe\u7cbe\u88fd\u7cbe\u88fd\u7cbe\u7cbe\u88fd\u7cbe\u88fd\u7cbe\u7cbe\u88fd\u7cbe\u7cbe\u7cbe\u88fd\u7cbe\u88fd\u7cbe\u88fd\u7cbe\u88fd\u786b\u7cbe\u5149\u7cbe\u5149\u5206\u5149\u5149\u5206\u5149\u8a08\uff08\u30b0"},"content":{"rendered":"

1. Method Overview<\/h2>\n
After the sample is digested, its absorbance is measured at a wavelength of 357.9 nm via graphite furnace atomization. Within a certain concentration range, the absorbance of chromium is proportional to its content. Quantitative determination is conducted by comparing with a standard series.<\/div>\n
\n

2. Instruments and Reagents<\/h2>\n<\/div>\n
\n

2.1 Instruments and Equipment<\/h3>\n

2.1.1 Testing Instruments<\/h4>\n
\n
\n\n\n\n\n\n\n\n
Serial No.<\/th>\nName<\/th>\nQuantity<\/th>\nTechnical Requirements<\/th>\nAccessories<\/th>\n<\/tr>\n<\/thead>\n
1<\/td>\nGraphite Furnace Atomic Absorption Spectrophotometer<\/td>\n1 set<\/td>\n–<\/td>\nChromium Hollow Cathode Lamp<\/td>\n<\/tr>\n
2<\/td>\nCirculating Water System<\/td>\n1 set<\/td>\n–<\/td>\n–<\/td>\n<\/tr>\n
3<\/td>\nArgon Gas<\/td>\n1 cylinder<\/td>\nPurity \u2265 99.99%<\/td>\n–<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/div>\n

2.1.2 Sample Pretreatment Equipment<\/h4>\n
\n
\n\n\n\n\n\n\n\n
Serial No.<\/th>\nName<\/th>\nQuantity<\/th>\nTechnical Requirements<\/th>\nAccessories<\/th>\n<\/tr>\n<\/thead>\n
1<\/td>\nPorcelain Crucible<\/td>\nSeveral<\/td>\nVolume: 100 mL<\/td>\n–<\/td>\n<\/tr>\n
2<\/td>\nElectric Furnace<\/td>\n1 set<\/td>\n–<\/td>\n–<\/td>\n<\/tr>\n
3<\/td>\nMicropipette<\/td>\n1 each<\/td>\nRanges: 100 \u03bcL ~ 1000 \u03bcL, 1000 \u03bcL ~ 5000 \u03bcL<\/td>\nTips: 1 mL, 5 mL<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/div>\n

2.2 Reagents<\/h3>\n

2.2.1 Raw Reagents<\/h4>\n
\n
\n\n\n\n\n\n
Serial No.<\/th>\nName<\/th>\nTechnical Requirements<\/th>\nRemarks<\/th>\n<\/tr>\n<\/thead>\n
1<\/td>\nNitric Acid<\/td>\nMOS Grade<\/td>\n–<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/div>\n

2.2.2 Prepared Reagents<\/h4>\n
\n
\n\n\n\n\n\n
Serial No.<\/th>\nName<\/th>\nPreparation Method<\/th>\nRemarks<\/th>\n<\/tr>\n<\/thead>\n
1<\/td>\nNitric Acid Solution (1+99)<\/td>\nMeasure 1 mL of nitric acid, add it to 99 mL of water, and mix well.<\/td>\n–<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/div>\n

2.3 Reference Standards<\/h3>\n

2.3.1 Stock Solution<\/h4>\n
\n
\n\n\n\n\n\n
Serial No.<\/th>\nNo.<\/th>\nName<\/th>\nTechnical Requirements<\/th>\nRemarks<\/th>\n<\/tr>\n<\/thead>\n
1<\/td>\nGSB 04-1740-2004<\/td>\nNational Liquid Standard Sample – Chromium<\/td>\nConcentration: 1000 \u03bcg\/mL<\/td>\nProvided by National Analysis and Testing Center for Nonferrous Metals and Electronic Materials<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/div>\n

3. Operational Procedures<\/h2>\n

3.1 Sample Preparation<\/h3>\n

3.1.1 Preparation of Test Solution<\/h4>\n
Weigh 5 g of the sample (accurate to 0.1 g) and place it in a 100 mL porcelain crucible. Heat the crucible on an electric furnace until the sample burns. Move the crucible to a fume hood and wait until the sulfur is completely burned out. Then, heat it on the electric furnace for another 5 minutes. Remove the crucible and let it cool. Add 5 mL of nitric acid and 15 mL of water, then heat until the residue is completely dissolved. After cooling, transfer the solution to a 25 mL colorimetric tube, dilute to the marked volume with water, and mix well.<\/div>\n

3.1.2 Preparation of Standard Solutions<\/h4>\n
    \n
  1. \n
    Preparation of Chromium Standard Intermediate Solution<\/p>\n
    <\/div>\n

    Accurately pipette 100 \u03bcL of the national chromium standard solution into a 100 mL volumetric flask. Dilute to the marked volume with (1+99) nitric acid solution to obtain a chromium standard intermediate solution with a concentration of 1 \u03bcg\/mL.<\/p><\/div>\n<\/li>\n

  2. \n
    Preparation of Chromium Standard Series<\/p>\n
    <\/div>\n

    Pipette 0.0, 0.25, 0.5, 1.0, and 2.0 mL of the chromium standard intermediate solution (1 \u03bcg\/mL) into separate 100 mL volumetric flasks respectively. Add (1+99) nitric acid solution to the marked volume to obtain a chromium standard series with concentrations of 0.0, 2.5, 5.0, 10.0, and 20.0 ng\/mL.<\/p><\/div>\n<\/li>\n<\/ol>\n

    3.2 Sample Testing<\/h3>\n

    (1) Testing Conditions<\/h4>\n
    Reference Conditions for Graphite Furnace Atomic Absorption Spectrophotometer<\/strong><\/div>\n
    <\/div>\n
    \n
    \n\n\n\n\n\n\n\n\n\n\n
    Parameter<\/th>\nSpecification<\/th>\n<\/tr>\n<\/thead>\n
    Element<\/td>\nChromium (Cr)<\/td>\n<\/tr>\n
    Wavelength (nm)<\/td>\n357.9<\/td>\n<\/tr>\n
    Spectral Bandwidth (nm)<\/td>\n0.4<\/td>\n<\/tr>\n
    Element Lamp Current (mA)<\/td>\n2.0<\/td>\n<\/tr>\n
    Filter Coefficient<\/td>\n0.1<\/td>\n<\/tr>\n
    Integration Time (s)<\/td>\n2<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/div>\n
    <\/div>\n
    Graphite Furnace Heating Program<\/strong><\/div>\n
    <\/div>\n
    \n
    \n\n\n\n\n\n
    Element<\/th>\nDrying Temperature (\u2103)<\/th>\nDrying Time (s)<\/th>\nAshing Temperature (\u2103)<\/th>\nAshing Time (s)<\/th>\nAtomization Temperature (\u2103)<\/th>\nAtomization Time (s)<\/th>\nCleaning Temperature (\u2103)<\/th>\nCleaning Time (s)<\/th>\n<\/tr>\n<\/thead>\n
    Cr<\/td>\n110<\/td>\n20<\/td>\n600<\/td>\n20<\/td>\n2300<\/td>\n3<\/td>\n2400<\/td>\n2<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/div>\n

    (2) Sample Testing<\/h4>\n
    Open the argon cylinder and adjust the argon pressure gauge to 0.5 MPa. Set the instrument to its optimal working state, and measure the absorbance of the reagent blank, standard series, and sample solution at a wavelength of 357.9 nm.<\/div>\n
    <\/div>\n
    Subtract the absorbance of the zero-standard solution from the absorbance of each standard solution. Plot a working curve with the mass concentration of chromium (\u03bcg\/L) as the abscissa and the corresponding absorbance as the ordinate. Based on the measured absorbance of the test solution and the blank test solution, find the mass of chromium from the working curve.<\/div>\n<\/div>\n