1,6-Hexanediamine for industrial use (3)

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The polarographic spectrometer was used to determine the polarographic wave around -1.

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Weigh 1,6 hexamethylene diamine (50±0.

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To pre-filled with 200mL ~ 300mL.

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3 Preparation of standard solution

As shown in Table 2, prepare 0#～3# standard solutions in four 100mL volumetric flasks and shake them evenly
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Table 2 Preparation of standard solution

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4 Determination of polarographic waves

Take 15mL of 0#～3# standard solution (i=0, 1, 2, 3) in sequence, add it to the electrolytic cell, bubbling nitrogen for 10 minutes to remove oxygen, and measure the 6 sensitivity of the polarograph (j=1, 2.
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…, 6) The extreme harmonic height h(i,j) in the gear
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5 Numerical calculation

The corresponding polarographic value PI _{(i) of} 1#～3# standard solution , the value is expressed in [mmol( isobutyraldehyde )/t( 1,6-hexanediamine )], calculated according to formula (2):

Where:

m— The mass of isobutyraldehyde added in solution A, in grams (g);

T ₁ - the mass fraction of isobutyraldehyde (5.
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1), the unit is percentage (%);

V _i —1#～3# The volume of solution A added to the standard solution, in milliliters (mL);

M— The value of the molar mass of isobutyraldehyde , in grams per mole (g/mol) (M=72.
107);

T2—The concentration of 1,6-hexamethylenediamine in solution B, the unit is percentage (%);

500—The volume of the volumetric flask, in milliliters (mL)
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The corresponding polarographic wave height difference of 1#～3# standard solution △h(i,j), the value is expressed in mm, calculated according to formula (3):

△h(i,j)=h(i,j)-h(0,j)……(3)

Where:

h(i,j)—1#～3# The polarographic wave height of the standard solution measured at the sensitivity of j block, the unit is millimeter (mm);

h(0,j)—0# The polarographic wave height of the standard solution measured at the sensitivity of j block, the unit is millimeter (mm)
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The corresponding coefficient f(i,j) of 1#～3# standard solution is calculated according to formula (4):

Where:

PI _(i) —1#～3# Polarographic value of standard solution, the unit is [mmol(isobutyraldehyde)/t(1,6-hexanediamine)];

△h(i,j)—The polarographic wave height difference, in millimeters (mm)
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The arithmetic mean fj of 1#～3# standard solution coefficients is calculated according to formula (5):

Where:

f(i,j)—The coefficients of various standard solutions at each sensitivity of the instrument
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6 Drawing standard curve

On logarithmic graph paper, plot the sensitivity of the polarograph versus f
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5 Analysis steps

Weigh a laboratory sample equivalent to 10g of 1,6-hexamethylenediamine with a mass fraction of 100%, accurate to 0.
01g, place it in a 100mL volumetric flask, dilute to the mark, shake well, take 15mL of this solution and add it to the electrolytic bubble.
Blow nitrogen until the start of bubbling, continue deoxygenation for 10 minutes, select appropriate sensitivity, and determine the extreme harmonics of the sample solution
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6 Result calculation

Polarographic value PI, the value is expressed in [mmol( isobutyraldehyde )/t(1,6-hexanediamine)], calculated according to formula (6):

Pl=hfj……(6)

Where:

h—The polarographic wave height of the sample solution, in millimeters (mm);

f _j — The arithmetic mean of the standard solution coefficients at the selected sensitivity
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Take the arithmetic average of the two measurement results as the measurement result, and the absolute difference between the two measurement results is not more than 12 [mmol ( isobutyraldehyde )/t (1,6-hexamethylene diamine)]
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Related links: Industrial 1,6-Hexanediamine (2)