Hanna-instruments HI 4004 Manual do Utilizador descarregar pdf (Página 14)

XII. XII.

XII.

Other Measurement TOther Measurement T

Other Measurement T

echniquesechniques

echniques

Known additionKnown addition

Known addition

An unknown concentration can be determined by adding a

known volume and concentration of Ca

standard to the

sample. mV values are noted before and after the addition

of standard (∆E). An ideal sensor slope can be used in the

equation but actual determined slopes at the temperature

of measurement should be used if known (S). This method

is preprogrammed in the Hanna HI 4222 pH/ISE/mV meter,

which simplifies the method greatly.

Example:

Calcium ion determination with known addition.

1. A 50 mL sample of unknown (V

SAMPLE

) is placed in a

clean plastic beaker with an electrode (s). One mL of

ISA is added to the sample and permitted to mix. mV

1 is recorded.

2. 10 mL (V

STANDARD

) of 10

-1

M (C

STANDARD

) standard is added

to the beaker and the mV value increases. (Note: for

other concentration samples, add a known volume

and concentration of standard to produce approxi-

mately 30 mV change).

The unknown calcium concentration in the original

sample (C

SAMPLE

) can then be determined by using the

equation that follows.

3. The procedure can be repeated with second standard

addition to verify slope and operation of the method.

sample

)10

∆E/S

- (V

S’

)

standard

sample

S’

sample

standard

ISA

)= V

sample

ISA

)= V

S’

XIII.XIII.

XIII.

pH and InterferentspH and Interferents

pH and Interferents

HI 4004/ HI 4104 calcium electrodes can operate over a

1 2 ... 9 10 11 12 13 14 15 16

Comentários a estes Manuais

Sem comentários

Hanna-instruments HI 4004 Manual do Utilizador Página 14

Comentários a estes Manuais

Manuais e produtos relacionados com Instrumentos de medida Hanna-instruments HI 4004