{"id":3995,"date":"2025-10-10T16:51:03","date_gmt":"2025-10-10T08:51:03","guid":{"rendered":"https:\/\/www.pgeneral.com\/?p=3995"},"modified":"2025-10-10T16:51:03","modified_gmt":"2025-10-10T08:51:03","slug":"determination-of-lead-in-olive-oil-graphite-furnace-atomic-absorption-spectrometry-2","status":"publish","type":"post","link":"https:\/\/www.pgeneral.com\/id\/applications\/determination-of-lead-in-olive-oil-graphite-furnace-atomic-absorption-spectrometry-2\/","title":{"rendered":"Penentuan Timbal dalam Minyak Zaitun (Spektrometri Penyerapan Atom Tungku Grafit)"},"content":{"rendered":"

1. Method Overview<\/h2>\n
After the sample is digested by microwave, it is injected into the graphite furnace of an atomic absorption spectrophotometer. After electrothermal atomization, it absorbs the resonance line at 283.3 nm. Within a certain concentration range, the absorbance is proportional to the lead content. Quantitative determination is performed by comparison with a standard series.<\/div>\n
\n

2. Instruments and Reagents<\/h2>\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>\nLead Hollow Cathode Lamp<\/td>\n<\/tr>\n
2<\/td>\nArgon Gas<\/td>\n1 cylinder<\/td>\nPurity \u2265 99.99%<\/td>\n–<\/td>\n<\/tr>\n
3<\/td>\nCirculating Cooling Water System<\/td>\n1 set<\/td>\n–<\/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\n\n\n
Serial No.<\/th>\nName<\/th>\nQuantity<\/th>\nTechnical Requirements<\/th>\nAccessories<\/th>\n<\/tr>\n<\/thead>\n
1<\/td>\nMicrowave Digestion System<\/td>\n1 set<\/td>\nEquipped with platinum resistance and infrared temperature measurement; pressure measurement accuracy: \u00b10.1 \u2103<\/td>\n–<\/td>\n<\/tr>\n
2<\/td>\nTemperature-Controlled Hot Plate<\/td>\n1 set<\/td>\n–<\/td>\n–<\/td>\n<\/tr>\n
3<\/td>\nElectronic Balance<\/td>\n1 set<\/td>\nSensitivity: 0.1 mg<\/td>\n–<\/td>\n<\/tr>\n
4<\/td>\nUltrapure Water System<\/td>\n1 set<\/td>\n–<\/td>\n–<\/td>\n<\/tr>\n
5<\/td>\nVolumetric Flask<\/td>\nSeveral<\/td>\nVolume: 100 mL<\/td>\n–<\/td>\n<\/tr>\n
6<\/td>\nTest Tube<\/td>\nSeveral<\/td>\nVolume: 10 mL<\/td>\n–<\/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\n\n\n
Serial No.<\/th>\nName<\/th>\nTechnical Requirements<\/th>\nRemarks<\/th>\n<\/tr>\n<\/thead>\n
1<\/td>\nDiammonium Hydrogen Phosphate<\/td>\nAnalytical Reagent (AR)<\/td>\n–<\/td>\n<\/tr>\n
2<\/td>\nHydrochloric Acid<\/td>\nGuaranteed Reagent (GR)<\/td>\n–<\/td>\n<\/tr>\n
3<\/td>\nNitric Acid<\/td>\nMOS Grade<\/td>\n–<\/td>\n<\/tr>\n
4<\/td>\nPalladium Nitrate<\/td>\nAnalytical Reagent (AR)<\/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\n\n
Serial No.<\/th>\nName<\/th>\nPreparation Method<\/th>\nRemarks<\/th>\n<\/tr>\n<\/thead>\n
1<\/td>\n(1+99) Nitric Acid Solution<\/td>\nMeasure 10 mL of nitric acid, slowly add it to 990 mL of water, and mix well.<\/td>\n–<\/td>\n<\/tr>\n
2<\/td>\n(5+95) Nitric Acid Solution<\/td>\nMeasure 5 mL of nitric acid, slowly add it to 95 mL of water, and mix well.<\/td>\n–<\/td>\n<\/tr>\n
3<\/td>\nDiammonium Hydrogen Phosphate – Palladium Nitrate Solution<\/td>\nWeigh 0.02 g of palladium nitrate, dissolve it with a small amount of (1+9) nitric acid solution. Then add 2 g of diammonium hydrogen phosphate, and after dissolution, dilute to 100 mL with (5+95) nitric acid solution. 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>\nGBW 08619<\/td>\nLead Single-Element Standard Substance Solution<\/td>\nConcentration: 1000 \u03bcg\/mL<\/td>\nProvided by National Institute of Metrology, China<\/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
Accurately weigh 0.2 g of the solid sample (accurate to 0.001 g) into a microwave digestion tank, add 5 mL of nitric acid, and digest the sample according to the microwave digestion operation steps. After cooling, take out the digestion tank and evaporate the acid on a hot plate at 140\u2103~160\u2103 until the volume is about 1 mL. After the digestion tank cools down, transfer the digestion solution to a 25 mL volumetric flask with deionized water. Wash the digestion tank 2~3 times with a small amount of water, combine the washing solutions into the volumetric flask, and dilute to the marked volume with water. Mix well for use; this is the sample test solution. Conduct a reagent blank test simultaneously.<\/div>\n
<\/div>\n
Microwave Heating Program<\/strong><\/div>\n
<\/div>\n
\n
\n\n\n\n\n\n\n\n\n\n
Step<\/th>\nTemperature (\u2103)<\/th>\nHolding Time (min)<\/th>\n<\/tr>\n<\/thead>\n
1<\/td>\n100<\/td>\n3<\/td>\n<\/tr>\n
2<\/td>\n120<\/td>\n3<\/td>\n<\/tr>\n
3<\/td>\n140<\/td>\n3<\/td>\n<\/tr>\n
4<\/td>\n160<\/td>\n3<\/td>\n<\/tr>\n
5<\/td>\n180<\/td>\n30<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/div>\n

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

    Lead standard intermediate solution (1.0 \u03bcg\/mL): Accurately pipette 0.1 mL of the lead standard solution (1000 \u03bcg\/mL) into a 100 mL volumetric flask, dilute to the marked volume with (1+99) nitric acid solution, and mix well.<\/p><\/div>\n<\/li>\n

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

    Accurately pipette 0.0, 0.1, 0.2, 0.3, and 0.4 mL of the lead standard intermediate solution (1.0 \u03bcg\/mL) into separate 10 mL volumetric flasks respectively. Dilute to the marked volume with (1+99) nitric acid solution to obtain lead standard series solutions with concentrations of 0.0, 10.0, 20.0, 30.0, and 40.0 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
    Element<\/th>\nLead<\/th>\n<\/tr>\n<\/thead>\n
    Wavelength (nm)<\/td>\n283.3<\/td>\n<\/tr>\n
    Spectral Bandwidth (nm)<\/td>\n0.4<\/td>\n<\/tr>\n
    Element Lamp Current (mA)<\/td>\n2<\/td>\n<\/tr>\n
    Background Correction Method<\/td>\nDeuterium Lamp<\/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\n\n\n
    Step<\/th>\nProcedure<\/th>\nTemperature (\u2103)<\/th>\nHeating Time (s)<\/th>\nHolding Time (s)<\/th>\n<\/tr>\n<\/thead>\n
    1<\/td>\nDrying<\/td>\n120<\/td>\n10<\/td>\n10<\/td>\n<\/tr>\n
    2<\/td>\nAshing<\/td>\n650<\/td>\n10<\/td>\n15<\/td>\n<\/tr>\n
    3<\/td>\nAtomization<\/td>\n1900<\/td>\n0<\/td>\n2<\/td>\n<\/tr>\n
    4<\/td>\nCleaning<\/td>\n2000<\/td>\n1<\/td>\n2<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/div>\n

    2) Sample Testing<\/h4>\n
    Inject 10 \u03bcL of each lead standard series solution and 5 \u03bcL of the diammonium hydrogen phosphate – palladium nitrate solution into the graphite furnace simultaneously in ascending order of mass concentration. After atomization, measure the absorbance. Plot a standard curve with mass concentration as the abscissa and absorbance as the ordinate. Input the sample weight, then read and record the results.<\/div>\n<\/div>\n