{"id":3270,"date":"2024-01-31T15:50:47","date_gmt":"2024-01-31T07:50:47","guid":{"rendered":"https:\/\/www.pgeneral.com\/?p=3270"},"modified":"2024-02-22T14:05:08","modified_gmt":"2024-02-22T06:05:08","slug":"determinacao-do-666-e-do-ddt-na-agua-potavel","status":"publish","type":"post","link":"https:\/\/www.pgeneral.com\/pt\/applications\/food-and-drugs\/determination-of-666-and-ddt-in-drinking-water\/","title":{"rendered":"Determina\u00e7\u00e3o de 666 e DDT em \u00e1gua pot\u00e1vel"},"content":{"rendered":"

(GB\/T 5750.9-2006 1 Standard inspection method for drinking water-Pesticide indicators- Gas Chromatography)<\/i><\/em><\/p>\n

 <\/p>\n

1 Overview of methods<\/b><\/strong><\/p>\n

Extract various isomers of DDT and BHC from water using cyclohexane, concentrate them, and separate and determine them using a gas chromatograph with an electron capture detector.<\/p>\n

2 Scope of application<\/b><\/strong><\/p>\n

This method is suitable for the determination of various isomers of BHC and DDT (\u03b1-666, \u03b3-666, \u03b2-666, \u03b4-666, p.p’- DDE, o.p’-DDT, p.p’- DDD, p.p’-DDT) determination.<\/p>\n

3 Reference basis<\/b><\/strong><\/p>\n

This method is based on the national standard GB\/T 5750.9-2006 1 Standard Test Methods for Drinking Water – Pesticide Indicators – Gas Chromatography.<\/p>\n

4 Instruments and reagents<\/b><\/strong><\/p>\n

4.1 Instruments and equipment<\/b><\/strong><\/p>\n

4.1.1 Testing instruments<\/b><\/strong><\/p>\n

\u00a0<\/b><\/strong><\/p>\n\n\n\n\n\n\n
Serial number<\/b><\/strong><\/td>\nName<\/b><\/strong><\/td>\nQuantity<\/b><\/strong><\/td>\nTechnical requirement<\/b><\/strong><\/td>\nAccessory<\/b><\/strong><\/td>\n<\/tr>\n
1<\/td>\ngas chromatography<\/td>\n1<\/td>\nInstrument model: Agilent 7890B<\/td>\nElectron capture detector<\/p>\n

(ECD)<\/td>\n<\/tr>\n

2<\/td>\nchromatographic column<\/td>\n1<\/td>\nDB-1701 Quartz Capillary Column (30m<\/p>\n

\u00d70.25mm\u00d70.25\u03bcm)<\/td>\n

\u00a0<\/b><\/strong><\/td>\n<\/tr>\n
3<\/td>\nhigh purity nitrogen<\/td>\n1<\/td>\n\uff1e99.999%<\/td>\n\u00a0<\/b><\/strong><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

\u00a0<\/b><\/strong><\/p>\n

4.1.2 Pre-treatment equipment<\/b><\/strong><\/p>\n\n\n\n\n\n\n\n
Serial number<\/b><\/strong><\/td>\nName<\/b><\/strong><\/td>\nQuantity<\/b><\/strong><\/td>\nTechnical requirement<\/b><\/strong><\/td>\nAccessory<\/b><\/strong><\/td>\n<\/tr>\n
1<\/td>\nRotary evaporator\/RE-2000B<\/td>\n1<\/td>\nSpeed: 0-200rpm; Temperature: Room<\/p>\n

Temperature~99 \u2103<\/td>\n

Equipped with a standard port collection<\/p>\n

Bottle (500ml)<\/td>\n<\/tr>\n

2<\/td>\nVacuum pump\/SHZ-iii<\/td>\n1<\/td>\nMaximum vacuum degree 0.09Mpa<\/td>\n\u00a0<\/b><\/strong><\/td>\n<\/tr>\n
3<\/td>\nLow-temperature thermostat\/YRDC<\/td>\n1<\/td>\nTemperature range -5 to 100 \u2103<\/td>\nPump flow rate 8L\/min<\/td>\n<\/tr>\n
4<\/td>\nanalytical balance<\/td>\n1<\/td>\nSensitivity: 0.0001g<\/td>\n\u00a0<\/b><\/strong><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

4.2 Reagents<\/b><\/strong><\/p>\n

4.2.1 Reagents<\/b><\/strong><\/p>\n

\u00a0<\/b><\/strong><\/p>\n\n\n\n\n\n
Serial number<\/b><\/strong><\/td>\nName<\/b><\/strong><\/td>\nQuantity<\/b><\/strong><\/td>\nTechnical requirement<\/b><\/strong><\/td>\nAccessory<\/b><\/strong><\/td>\n<\/tr>\n
1<\/td>\ncyclohexane<\/td>\n1<\/td>\nHPLC<\/td>\n\u00a0<\/b><\/strong><\/td>\n<\/tr>\n
2<\/td>\nAnhydrous sodium sulfate<\/td>\n1<\/td>\nanalytical grade<\/td>\n\u00a0<\/b><\/strong><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

\u00a0<\/b><\/strong><\/p>\n

4.2.2 Preparation of reagents<\/b><\/strong><\/p>\n

\u00a0<\/b><\/strong><\/p>\n\n\n\n\n
Serial number<\/b><\/strong><\/td>\nName<\/b><\/strong><\/td>\nPreparation method<\/b><\/strong><\/td>\nRemarks<\/b><\/strong><\/td>\n<\/tr>\n
1<\/td>\n<\/td>\n<\/td>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

\u00a0<\/b><\/strong><\/p>\n

4.3 Standard products<\/b><\/strong><\/p>\n

4.3.1 Stock solution<\/b><\/strong><\/p>\n

\u00a0<\/b><\/strong><\/p>\n\n\n\n\n\n
Number<\/b><\/strong><\/td>\nSerial number<\/b><\/strong><\/td>\nName<\/b><\/strong><\/td>\nTechnical requirement<\/b><\/strong><\/td>\nRemarks<\/b><\/strong><\/td>\n<\/tr>\n
1<\/td>\nYJLHH(L)20200617-1 ~2<\/td>\n666, DDT standard solution<\/td>\n100\u03bcg\/mL<\/td>\n\u00a0<\/b><\/strong><\/td>\n<\/tr>\n
<\/td>\n<\/td>\n<\/td>\n\u00a0<\/b><\/strong><\/td>\n\u00a0<\/b><\/strong><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

5 Operation process<\/b><\/strong><\/p>\n

5.1 Sample processing<\/b><\/strong><\/p>\n

5.1.1 Preparation of test solution<\/b><\/strong><\/p>\n

5.1.2 Preparation of standard solution<\/b><\/strong><\/p>\n

\u00a0<\/b><\/strong><\/p>\n

    \n
  1. 666, DDT standard stock solution: 100\u03bcg\/mL.<\/li>\n
  2. 666, DDT standard intermediate solution (10 \u03bcg\/mL): Accurately draw 100 \u03bcL of standard stock solution in a 1mL volumetric flask, dilute to volume with cyclohexane and shake well. Prepare when needed.<\/li>\n
  3. 666, DDT standard working solution 1~5: accurately draw 5\u03bcL, 10\u03bcL, 20\u03bcL, 40\u03bcL, and 50\u03bcL in a 1mL volumetric flask, dilute with cyclohexane and make it to volume. The concentration of the standard working solutions becomes 0.05\u03bcg\/mL, 0.1\u03bcg\/mL, 0.2\u03bcg\/mL, 0.4\u03bcg\/mL, and 0.5\u03bcg\/mL. These standard working solutions are prepared for temporary use.<\/li>\n<\/ol>\n

     <\/p>\n

    5.2 Sample testing<\/b><\/strong><\/p>\n

    1) Testing conditions<\/b><\/strong><\/p>\n\n\n\n\n\n\n\n\n\n\n
    Injector temperature<\/td>\n260\u2103<\/td>\n<\/tr>\n
    Split flow mode<\/td>\nSplit flow, split ratio 10:1<\/td>\n<\/tr>\n
    Injection volume<\/td>\n1\u03bcL<\/td>\n<\/tr>\n
    Column oven<\/td>\nMaintain 210 \u2103 for 30 minutes<\/td>\n<\/tr>\n
    Detector temperature<\/td>\n260\u2103<\/td>\n<\/tr>\n
    Column flow<\/td>\n1mL\/min<\/td>\n<\/tr>\n
    Makeup airflow<\/td>\n40 mL\/min<\/td>\n<\/tr>\n
    Carrier gas<\/td>\nHigh purity nitrogen<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

    2) Sample testing<\/b><\/strong><\/p>\n

    Take 500mL of water sample and place it in a 1000mL separating funnel. Add 70mL of cyclohexane or petroleum ether and extract it three times (30mL, 20mL, 20mL). Shake thoroughly for 3 minutes each time, let it stand for layering, combine the cyclohexane extraction solution, dehydrate it with anhydrous sodium sulfate, and concentrate it to 1mL for measurement.<\/p>\n

    5.3 Result Calculation<\/b><\/strong><\/p>\n

    \u03c1(B)=\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0(1)<\/p>\n

    In the formula:<\/p>\n

    \u03c1(B)\u2014The mass concentration of each monomer DDT or various isomers of BHC in the water sample, in micrograms<\/p>\n

    per liter (ug\/L);<\/p>\n

    \u03c11<\/sub>\u00a0\u2014The mass concentration equivalent to the standard curve, in micrograms per milliliter (ug\/mL);<\/p>\n

    \u2014The total volume of the extraction solution, in milliliters (mL)\u00a0;<\/p>\n

    V \u2014The volume of the water sample, in milliliters (mL).<\/p>\n

    6 Appendix (applicable to method validation, etc.)<\/b><\/strong><\/p>\n

    6.1 Detection limit<\/b><\/strong><\/p>\n

    This method has a detection limit of 0.02 \u03bcg\/L for each isomer of DDT when the sampling volume of drinking water is 500 mL, and each isomer of 666 is 0.01\u03bcg\/L.<\/p>\n

    6.2 Precision<\/b><\/strong><\/p>\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
    Test items<\/td>\nSerial number<\/td>\n1<\/td>\n2<\/td>\n3<\/td>\n4<\/td>\n5<\/td>\n6<\/td>\n7<\/td>\n<\/tr>\n
     <\/p>\n

    \u03b1-666<\/td>\n

    		Spike concentration (\u03bcg\/L)<\/td>\n25<\/td>\n<\/tr>\n
    Actual value (\u03bcg\/L)<\/td>\n24.8<\/td>\n25.4<\/td>\n25.2<\/td>\n25.1<\/td>\n26.0<\/td>\n25.6<\/td>\n25.5<\/td>\n<\/tr>\n
    RSD\uff08%\uff09<\/td>\n1.19<\/td>\n<\/tr>\n
     <\/p>\n

    \u03b3-666<\/td>\n

    		Spike concentration (\u03bcg\/L)<\/td>\n25<\/td>\n<\/tr>\n
    Actual value (\u03bcg\/L)<\/td>\n26.0<\/td>\n26.1<\/td>\n26.0<\/td>\n26.1<\/td>\n26.2<\/td>\n26.8<\/td>\n26.0<\/td>\n<\/tr>\n
    RSD\uff08%\uff09<\/td>\n1.1<\/td>\n<\/tr>\n
     <\/p>\n

    \u03b2-666<\/td>\n

    		Spike concentration (\u03bcg\/L)<\/td>\n25<\/td>\n<\/tr>\n
    Actual value (\u03bcg\/L)<\/td>\n25.5<\/td>\n24.5<\/td>\n27.2<\/td>\n27.4<\/td>\n27.9<\/td>\n27.8<\/td>\n28.0<\/td>\n<\/tr>\n
    RSD\uff08%\uff09<\/td>\n5.54<\/td>\n<\/tr>\n
     <\/p>\n

    \u03b4-666<\/td>\n

    		Spike concentration (\u03bcg\/L)<\/td>\n25<\/td>\n<\/tr>\n
    Actual value (\u03bcg\/L)<\/td>\n25.5<\/td>\n25.2<\/td>\n26.5<\/td>\n27.1<\/td>\n26.9<\/td>\n25.0<\/td>\n25.0<\/td>\n<\/tr>\n
    RSD\uff08%\uff09<\/td>\n4.26<\/td>\n<\/tr>\n
     <\/p>\n

    p.p’- DDE<\/td>\n

    		Spike concentration (\u03bcg\/L)<\/td>\n50<\/td>\n<\/tr>\n
    Actual value (\u03bcg\/L)<\/td>\n46.3<\/td>\n48.0<\/td>\n46.0<\/td>\n46.0<\/td>\n45.8<\/td>\n45.0<\/td>\n46.1<\/td>\n<\/tr>\n
    RSD\uff08%\uff09<\/td>\n1.95<\/td>\n<\/tr>\n
     <\/p>\n

    o.p’-DDT<\/td>\n

    		Spike concentration (\u03bcg\/L)<\/td>\n50<\/td>\n<\/tr>\n
    Actual value (\u03bcg\/L)<\/td>\n46.2<\/td>\n48.0<\/td>\n44.8<\/td>\n48.3<\/td>\n48.1<\/td>\n48.0<\/td>\n49.0<\/td>\n<\/tr>\n
    RSD\uff08%\uff09<\/td>\n3.11<\/td>\n<\/tr>\n
     <\/p>\n

    p.p’- DDD<\/td>\n

    		Spike concentration (\u03bcg\/L)<\/td>\n50<\/td>\n<\/tr>\n
    Actual value (\u03bcg\/L)<\/td>\n45.5<\/td>\n46.8<\/td>\n45.3<\/td>\n45.6<\/td>\n46.0<\/td>\n46.2<\/td>\n49.1<\/td>\n<\/tr>\n
    RSD\uff08%\uff09<\/td>\n2.86<\/td>\n<\/tr>\n
     <\/p>\n

    p.p’-DDT<\/td>\n

    		Spike concentration (\u03bcg\/L)<\/td>\n50<\/td>\n<\/tr>\n
    Actual value (\u03bcg\/L)<\/td>\n47.0<\/td>\n47.6<\/td>\n45.7<\/td>\n47.2<\/td>\n47.4<\/td>\n46.5<\/td>\n46.5<\/td>\n<\/tr>\n
    RSD\uff08%\uff09<\/td>\n1.38<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

    \u00a0<\/b><\/strong><\/p>\n

     <\/p>\n

     <\/p>\n

    6.3 Accuracy<\/b><\/strong><\/p>\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
    Testing items<\/td>\nAdded concentration (mg\/L)<\/td>\nAdded concentration (mg\/L)<\/td>\nAverage recovery rate<\/p>\n

    (%)<\/td>\n<\/tr>\n

     <\/p>\n

    \u03b1-666<\/td>\n

    		0.05<\/td>\n100.2<\/td>\n97.8<\/td>\n100.3<\/td>\n99.4<\/td>\n<\/tr>\n
    0.1<\/td>\n91.5<\/td>\n93.3<\/td>\n89.5<\/td>\n91.4<\/td>\n<\/tr>\n
    0.5<\/td>\n91.3<\/td>\n90.7<\/td>\n88.4<\/td>\n90.1<\/td>\n<\/tr>\n
     <\/p>\n

    \u03b3-666<\/td>\n

    		0.05<\/td>\n99.95<\/td>\n97.9<\/td>\n101.7<\/td>\n99.85<\/td>\n<\/tr>\n
    0.1<\/td>\n92.3<\/td>\n93.7<\/td>\n90.2<\/td>\n92.1<\/td>\n<\/tr>\n
    0.5<\/td>\n93.6<\/td>\n93.6<\/td>\n90.7<\/td>\n92.6<\/td>\n<\/tr>\n
     <\/p>\n

    \u03b2-666<\/td>\n

    		0.05<\/td>\n102.4<\/td>\n100.9<\/td>\n105.8<\/td>\n103.0<\/td>\n<\/tr>\n
    0.1<\/td>\n93.0<\/td>\n95.0<\/td>\n91.5<\/td>\n93.2<\/td>\n<\/tr>\n
    0.5<\/td>\n95.3<\/td>\n95.5<\/td>\n93.2<\/td>\n94.7<\/td>\n<\/tr>\n
     <\/p>\n

    \u03b4-666<\/td>\n

    		0.05<\/td>\n97.0<\/td>\n96.1<\/td>\n99.0<\/td>\n97.4<\/td>\n<\/tr>\n
    0.1<\/td>\n92.0<\/td>\n91.1<\/td>\n92.4<\/td>\n91.8<\/td>\n<\/tr>\n
    0.5<\/td>\n94.5<\/td>\n94.9<\/td>\n91.6<\/td>\n93.7<\/td>\n<\/tr>\n
     <\/p>\n

    p.p’- DDE<\/td>\n

    		0.05<\/td>\n100.8<\/td>\n98.7<\/td>\n102.9<\/td>\n100.8<\/td>\n<\/tr>\n
    0.1<\/td>\n92.3<\/td>\n93.7<\/td>\n91.7<\/td>\n92.6<\/td>\n<\/tr>\n
    0.5<\/td>\n95.0<\/td>\n95.5<\/td>\n92.5<\/td>\n94.3<\/td>\n<\/tr>\n
     <\/p>\n

    o.p’-DDT<\/td>\n

    		0.05<\/td>\n96.1<\/td>\n95.9<\/td>\n100.3<\/td>\n97.4<\/td>\n<\/tr>\n
    0.1<\/td>\n89.7<\/td>\n92.2<\/td>\n89.2<\/td>\n90.4<\/td>\n<\/tr>\n
    0.5<\/td>\n94.8<\/td>\n95.9<\/td>\n93.0<\/td>\n95.6<\/td>\n<\/tr>\n
     <\/p>\n

    p.p’- DDD<\/td>\n

    		0.05<\/td>\n100.2<\/td>\n100.3<\/td>\n104.2<\/td>\n101.6<\/td>\n<\/tr>\n
    0.1<\/td>\n91.3<\/td>\n94.4<\/td>\n91.0<\/td>\n92.2<\/td>\n<\/tr>\n
    0.5<\/td>\n94.6<\/td>\n95.7<\/td>\n92.8<\/td>\n94.4<\/td>\n<\/tr>\n
     <\/p>\n

    p.p’-DDT<\/td>\n

    		0.05<\/td>\n98.3<\/td>\n94.4<\/td>\n99.7<\/td>\n97.5<\/td>\n<\/tr>\n
    0.1<\/td>\n92.8<\/td>\n92.6<\/td>\n90.3<\/td>\n91.9<\/td>\n<\/tr>\n
    0.5<\/td>\n96.2<\/td>\n96.2<\/td>\n93.3<\/td>\n95.2<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

    6.4 Linear range<\/b><\/strong><\/p>\n

    The linear range of this method is 0.05mg\/L~0.5mg\/L.<\/p>\n

    6.5 Other<\/b><\/strong><\/p>\n

     
    \n