{"id":3786,"date":"2025-07-28T15:05:00","date_gmt":"2025-07-28T07:05:00","guid":{"rendered":"https:\/\/www.pgeneral.com\/?p=3786"},"modified":"2025-07-28T15:05:17","modified_gmt":"2025-07-28T07:05:17","slug":"determination-of-cadmium-in-nettle-leaves-hydride-generation-atomic-fluorescence-spectrometry","status":"publish","type":"post","link":"https:\/\/www.pgeneral.com\/ja\/applications\/determination-of-cadmium-in-nettle-leaves-hydride-generation-atomic-fluorescence-spectrometry\/","title":{"rendered":"\u30cd\u30c8\u30eb\u306e\u8449\u306e\u30ab\u30c9\u30df\u30a6\u30e0\u306e\u6c7a\u5b9a\uff08\u6c34\u5316\u7269\u751f\u6210\u539f\u5b50\u6c34\u6c34\u539f\u539f\u5b50\u6c34\u6c34\u6c34\u6c34\u6c34\u5316\u7269\u767a\u751f\u539f\u5b50\u8367\u5149\u30b9\u30da\u30af\u30c8\u30ed\u30e1\u30c8\u30ea\uff09"},"content":{"rendered":"

1. Method Overview<\/h2>\n
After microwave digestion of the sample, atomic fluorescence is generated under excitation by a high-intensity cadmium hollow cathode lamp. The fluorescence intensity is proportional to the concentration of cadmium in the test solution under fixed conditions, and quantification 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
Serial No.<\/th>\nName<\/th>\nQuantity<\/th>\nTechnical Requirements<\/th>\nAccessories<\/th>\n<\/tr>\n<\/thead>\n
1<\/td>\nAtomic fluorescence spectrometer<\/td>\n1 set<\/td>\n<\/td>\nCadmium hollow cathode lamp<\/td>\n<\/tr>\n
2<\/td>\nArgon gas<\/td>\n1 cylinder<\/td>\nPurity \u2265 99.999%<\/td>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

2.1.2 Pretreatment Equipment<\/h4>\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>\nElectronic balance<\/td>\n1 set<\/td>\nSensitivity: 1 mg<\/td>\n<\/td>\n<\/tr>\n
2<\/td>\nMicrowave digestion system<\/td>\n1 set<\/td>\n<\/td>\nPTFE digestion inner tank, digestion and acid-removal device<\/td>\n<\/tr>\n
3<\/td>\nAdjustable electric hot plate<\/td>\n1 set<\/td>\n\/<\/td>\n<\/td>\n<\/tr>\n
4<\/td>\nMicropipette<\/td>\n1 each<\/td>\n100 \u03bcL~1000 \u03bcL; 1000 \u03bcL~5000 \u03bcL<\/td>\n<\/td>\n<\/tr>\n
5<\/td>\nColorimetric tube<\/td>\nSeveral<\/td>\n10 mL<\/td>\n<\/td>\n<\/tr>\n
6<\/td>\nVolumetric flask<\/td>\nSeveral<\/td>\n100 mL<\/td>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

2.2 Reagents<\/h3>\n

2.2.1 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>\nNitric acid<\/td>\nGuaranteed reagent<\/td>\n<\/td>\n<\/tr>\n
2<\/td>\nHydrochloric acid<\/td>\nGuaranteed reagent<\/td>\n<\/td>\n<\/tr>\n
3<\/td>\nThiourea<\/td>\nAnalytical reagent<\/td>\n<\/td>\n<\/tr>\n
4<\/td>\nPotassium hydroxide<\/td>\nAnalytical reagent<\/td>\n<\/td>\n<\/tr>\n
5<\/td>\nPotassium borohydride<\/td>\nAnalytical reagent<\/td>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

2.2.2 Prepared Reagents<\/h4>\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>\nHydrochloric acid solution (1+99)<\/td>\nMeasure 1 mL of hydrochloric acid into a 100 mL volumetric flask containing a small amount of water, then add water to the mark.<\/td>\n<\/td>\n<\/tr>\n
2<\/td>\nCarrier solution (1% thiourea + 0.5% hydrochloric acid + 0.1% cobalt standard solution)<\/td>\nWeigh 10 g of thiourea into a 1000 mL volumetric flask containing a small amount of water. After dissolution, add 5 mL of hydrochloric acid and 1 mL of 1000 \u03bcg\/mL cobalt standard solution, then dilute to the mark with deionized water.<\/td>\n<\/td>\n<\/tr>\n
3<\/td>\nReducing agent (1% potassium hydroxide + 1.5% potassium borohydride)<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

2.3 Reference Standards<\/h3>\n

2.3.1 Stock Solutions<\/h4>\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>\nGBW08619<\/td>\nCadmium single-element solution standard substance<\/td>\n1000 \u03bcg\/mL<\/td>\nNational Institute of Metrology, China<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

3. Operational Procedures<\/h2>\n

3.1 Preparation of Test Solution<\/h3>\n
Weigh 0.5 g of the sample into a digestion tube, add 8 mL of nitric acid, shake to mix evenly, and digest in a microwave digestion instrument. The recommended microwave digestion conditions are shown in the table below (digestion conditions can be adjusted according to different instruments). After digestion, cool the tube, place it in a digestion and acid-removal device, and heat at 140\u00b0C until completely dry. Add a small amount of water and continue heating to dryness (repeat three times). Remove and cool, add 0.1 mL of hydrochloric acid, transfer to a 10 mL colorimetric tube with deionized water, dilute to the mark, and mix well for testing. Perform a reagent blank test simultaneously.<\/div>\n
Microwave Digestion Heating Program<\/strong><\/div>\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>\n80<\/td>\n3<\/td>\n<\/tr>\n
2<\/td>\n120<\/td>\n5<\/td>\n<\/tr>\n
3<\/td>\n140<\/td>\n5<\/td>\n<\/tr>\n
4<\/td>\n160<\/td>\n5<\/td>\n<\/tr>\n
5<\/td>\n180<\/td>\n30<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

3.2 Preparation of Standard Solutions<\/h3>\n
    \n
  1. \n
    Preparation of cadmium standard intermediate solution (1 \u03bcg\/mL): Accurately pipette 0.10 mL of cadmium standard stock solution (1000 \u03bcg\/mL) into a 100 mL volumetric flask, dilute to the mark with (1+99) hydrochloric acid solution, and shake well.<\/div>\n<\/li>\n
  2. \n
    Preparation of cadmium standard working solution (1 ng\/mL): Accurately pipette 0.1 mL of cadmium standard intermediate solution (1 \u03bcg\/mL) into a 100 mL volumetric flask, dilute to the mark with (1+99) hydrochloric acid solution, and shake well.<\/div>\n<\/li>\n
  3. \n
    Preparation of cadmium standard series: The instrument automatically dilutes to prepare a standard series with concentrations of 0.00 ng\/mL, 0.10 ng\/mL, 0.20 ng\/mL, 0.40 ng\/mL, 0.80 ng\/mL, and 1.00 ng\/mL.<\/div>\n<\/li>\n<\/ol>\n

    3.3 Sample Testing<\/h3>\n
      \n
    1. Testing Conditions<\/strong> Reference Conditions for Atomic Fluorescence Spectrometer<\/strong><\/li>\n<\/ol>\n
      \n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
      Parameter<\/th>\nValue<\/th>\n<\/tr>\n<\/thead>\n
      Negative high voltage (V)<\/td>\n280<\/td>\n<\/tr>\n
      Lamp current (mA)<\/td>\n40\/40<\/td>\n<\/tr>\n
      Atomization temperature (\u2103)<\/td>\n200<\/td>\n<\/tr>\n
      Carrier gas flow rate (mL\/min)<\/td>\n300<\/td>\n<\/tr>\n
      Shielding gas flow rate (mL\/min)<\/td>\n600<\/td>\n<\/tr>\n
      Measurement method<\/td>\nStandard curve method<\/td>\n<\/tr>\n
      Reading mode<\/td>\nPeak area<\/td>\n<\/tr>\n
      Delay time (s)<\/td>\n2.0<\/td>\n<\/tr>\n
      Reading time (s)<\/td>\n20<\/td>\n<\/tr>\n
      Sample injection volume (mL)<\/td>\n1.0<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
        \n
      1. Sample Testing<\/strong> Adjust the instrument to the optimal state. Use the mixed solution of 1% thiourea + 0.5% hydrochloric acid + 0.1% cobalt standard solution as the carrier solution, and the mixed solution of 1% potassium hydroxide + 1.5% potassium borohydride as the reducing agent. After the carrier blank discriminant value is less than 10, inject the cadmium standard working solution to determine its fluorescence intensity. Plot a standard curve with mass concentration as the abscissa and fluorescence intensity as the ordinate.<\/li>\n<\/ol>\n
        Under the same experimental conditions as the standard series, introduce the blank solution and sample solution into the instrument respectively, determine their fluorescence intensities, and quantify by comparison with the standard series.<\/div>\n

        3.4 Result Calculation<\/h3>\n
        The concentration of cadmium in the sample is calculated by the following formula:<\/div>\n
        \"\"<\/div>\n
        Where:<\/div>\n
        \u03c1(Cd)<\/span>\u00a0\u2014\u2014 Mass concentration of cadmium in the sample, in milligrams per kilogram (mg\/kg);<\/div>\n
        \u03c11<\/span> \u2014\u2014 Concentration of cadmium in the sample obtained from the calibration curve, in nanograms per milliliter (ng\/mL);<\/div>\n
        V1<\/span>\u2014\u2014 Volume of the sample solution for determination, in milliliters (mL);<\/div>\n
        m<\/span>\u00a0\u2014\u2014 Mass of the sample, in grams (g);<\/div>\n
        1000 \u2014\u2014 Conversion factor.<\/div>\n<\/div>\n<\/div>\n