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Tester for Pesticide residues introduction 1

           Tester for Pesticide residues introduction 1

Testing Principle

After digestion to the sample , all metals (Arsenic, Lead,Mercury, Cadmium, Chromium) are into ionic form , heavy metal
and dithizone solution can form purple solution in near-neutralconditions . Solution color is proportional with content of
heavy metal in a certain concentration range , it obey“ Lambert-Beer Law “ :
E=K*C*L
E:Extinction; K:Extinction Coefficient; C: SolutionConcentration; L: Solution Thickness .
We can get : C=E/KL
Suppose solution to be tested is C2,if K,L is same,
Then , C2=E2/E1*C1
We can get E2/E1 from instrument test , C1 is standardsolution ,when we input C1 ,instrument can calculate and
display C2 automatically .
B、Technical Index :
1,Stability : displayed number(transmittance measurement) drift is less than 0.7 % (A) , within 3
minutes after powering on for 20 minutes .
2,Sensitivity : Kλ≥3.4×10-3 , (testing in Potassium dichromate standard solution).
3,Repeatability : error ≤ 0.003 (A) , (testing in Potassium dichromate standard solution).
4,Linear error : Absorbance range : 0.1~0.3,linear error ≤±6% ;0.3~0.6 , linear error : ≤
±4% ;0.6~0.8,linear error ≤ ±5%(testing in Potassium dichromate standard solution) .
1. Power consumption : ≤ 5W .
2. Cultivate heating power : ≤ 100W .
C、Testing Items :
1. Heavy metal in the food .
2. Pesticide residue in the food .
Nitrate and nitrite in the food .
Formaldehyde, sulfoxylate, Sulfur dioxide

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