Specificity of analytical methods used to determine the concentration of formaldehyde in workroom air

Chemosphere, Vol.13, No.4, P r i n t e d in Great B r i t a i n

pp 521 - 525,

1984

0 0 4 5 - 6 5 3 5 / 8 4 $3.00 + .00 ©1984 P e r g a m o n Press Ltd.

S P E C I F I C I T Y OF A N A L Y T I C A L M E T H O D S USED TO D E T E R M I N E THE C O N C E N T R A T I O N OF F O R M A L D E H Y D E IN W O R K R O O M A I R Ilpo Ahonen*, Tampere

Eero Priha

and M a r j a - L i i s a

Aij~l~

Regional Institute of O c c u p a t i o n a l Health Box 486, SF-33101 T a m p e r e i0 F i n l a n d

ABSTRACT

I n t e r f e r e n c e s from 17 c o m m o n l y occurring o r g a n i c c o m p o u n d s to the d e t e r m i n a t i o n of f o r m a l d e h y d e have b e e n studied. The tested m e t h o d s were a c e t y l a c e t o n e ( c o l o r i m e t r i c and fluorometric) c h r o m o t r o p i c acid (with and w i t h o u t evaporation), MBTH, p a r a r o s a n i l i n e and 2 , 4 - d i n i t r o p h e n y l h y d r a t z i n e - H P L C methods.

INTRODUCTION

Several

analytical

formaldehyde published serious

methods

in w o r k r o o m

m a n y other

respect

used

air p o l l u t a n t s

Specificity

is p e r h a p s

chromotropic

occur

with

retained

according

to an a c e t y l a c e t o n e

may

interferences

•

cause

be more

specific

knowledge method

about

the

sample level

actual

method

specific

with

methods

ketones

can

sampling

9 .

other

The

no other

or p o t e n t i a l

interfere

methods.

from m a n y

to dryness

of f o r m a l d e h y d e

aldehydes,

amines,

is one way is d e t e r m i n e d

and k e t o c o m p o u n d s

p r o c e d u r e 5 has been but there

of total

limited

claimed

hydrazone

aliphatic

(MBTH)

a l d e h y d e s 6. When

can be used

information

to

is no systematic

about

to d e t e r m i n e the effects

i n t e r f e r e n c e s I'7. A 2,4-dinitrophenylhydroazine

f o r m a l d e h y d e 8'9. with

in w h i c h

a l d e h y d e s I, phenol I, ethanol 2,

the M B T H m e t h o d

is only

air,

to suffer

3-methyl-2-benzothiazolone

HPLC or GC a n a l y s i s

for

reported

acid method,

aldehydes,

There

is e s p e c i a l l y

in w o r k r o o m

solution

level

for d e t e r m i n a t i o n s

of f o r m a l d e h y d e .

of n u m e r o u s

method,

the c h r o m o t r o p i c

used

contains

the

. The p a r a r o s a n i l i n e

interferences.

is c o m m o n l y

the

(DNPH)

than

4

When

of

study has been

lack

the s p e c t r o p h o t o m e t r i c

has been

such as a l c o h o l s I, other

interferences.

concentration

formaldehyde.

problem with

and x y l e n e s 2. E v a p o r a t i o n 3 of the a b s o r p t i o n to expel

This

of f o r m a l d e h y d e

acid p r o c e d u r e

the

no systematic

compounds.

together

the g r e a t e s t

interferences

to d e t e r m i n e

but v i r t u a l l y

from o r g a n i c

to m e a s u r e m e n t s

The c l a s s i c negative

air,

on i n t e r f e r e n c e s

with

have been

the m e t h o d

is c o m m o n l y Only

large

if 2 , 4 - D N P H

521

considered

amounts coated

one of the most

of other XAD-2

aldehydes

resin

is used

or for

522

This paper

discusses

formaldehyde. occur

Most

together

clinical

the

specificity

of the

with

studied

formaldehyde

laboratories,

and

studied

acetylacetone

TABLE

i.

and

Methods

are

five

potential

commonly

used methods

interferences

in t h e w o o d w o r k i n g

were

to determine

solvents,

industry,

which

foundries,

elsewhere.

RESULTS

The methods

of

shown

chromotropic

AND DISCUSSION

in t a b l e acid

i. T w o d i f f e r e n t

methods

were

modifications

of the

tested.

studied

Method

Absorption

Wavelength

solution

nm

Reference

or adsorbent

acetylacetone

i0 % m e t h a n o l

- colorimetric

(AAcolor.)

- fluorometric

(AAfluor.)

chromotropic - without (CTA - with (CTA

4,

in w a t e r

i0

415 410ex/510em

acid

1%

evaporation

sodium

580

ii

340

9,

610

13

570

5

bisulfite

)

no evap. evaporation evap.

)

2,4-dinitrophenylhydrazine-

XAD-2

HPLC

with

2,4-DNPH

0.05

% MBTH

(DNPH)

3-methyl-2-benzothiazolone hydrazone

coated

12

(MBTH)

pararosaniline

(PRA)

distilled water

As

can be

seen

from table

the d e t e r m i n a t i o n deviation

of

2,

several

formaldehyde.

of each method

are here

o f the

compounds

Only differences considered

studied

over

as a c t u a l

twice

interfered the

with

standard

interferences.

523

TABLE

2.

Effects

of

the

compounds

tested

on

the

results

of

formaldehyde

Relative

result I

(i p p m

HCHO

= i00)

Mole AA

ratio

CTA

DNPH

color

Compound

MBTH

PRA

fluor

no evap.

evap.

i00

i01

96*

102

i00

100

i00

n-propanol

99

98

96*

103

i00

i00

i00

i-propanol

ethanol

i00:i

i00

99

85*

102

i00

i01

99

n-butanol

99

I00

88*

103

i00

i00

i00

i-butanol

99

i00

67*

i01

i00

i01

i00

methyl

i-butylketone

i00

96

95*

109"

I00

103"

i01

113"

115"

117"

129"

114"

152"

119"

"

I00

98

98

106"

92

i01

i00

"

i01

98

92*

106"

92

103"

i01

"

99

103

26*

102

i00

I00

"

99

98

70*

104"

92

113"

i01

"

i00

99

35*

107"

92

112"

103"

i01

2-ethoxyethanol (cellosolve) ethyl

acetate

n-butyl

acetate

xylene white

spirit

aromatic

white

(Shellosol furfuryl

spirit

i00

A) 5:1

i01

93*

acetaldehyde

"

i01

95

acrolein

"

i01

102

"

i00

99

96*

104"

102

i00

i00

"

i00

i00

17"

109"

102

i00

99

formic

alcohol

acid

phenol

*

interference

i)

each

The

compounds

excess. pling and

is

way

procedure A)

Therefore

concluded

2 x relative the

tested

In t h i s

Shellsol

utions. be

>+

result

on

mean

were the

not

the the

standard three

injected

maximum

especially are

of

actual

basis

of

into

table

158"

103

>>150"

120"

98

103

102

>>150"

112"

of

absorption was

compounds

2.

102

104"

in

the

method

determinations

solutions obtained.

(such

quantitatively

interference

134"

88*

deviation

duplicate

interference

nonpolar

absorbed

i00

into

such

as

at

xylene,

aqueous

case

a certain

In n o r m a l white

air

spirit,

absorption

is m u c h

lower

molar sam-

sol-

than

can

524

It is o b v i o u s aldehyde results

Mole

compound

since

(Riedel

it c a u s e d

de H a e n

a positive

corresponding

that

to interference

an e r r o r

the

over

of

i0 % ( t a b l e

interference

3.

Interpolated

Compound

is

i0 % w e r e 3).

linearly

mole

ratios

Mole

(about

some

15 %)

The

calculated

calculation

correlated

that

ratio

caused

with

formin the

for e a c h

is b a s e d

the

i-propanol

67

n-butanol

83

i-butanol

30

xylene

14

white

spirit

aromatic

white

(Shellsoll furfuryl

spirit

33

77

15

83

A) 1,6

0,9

4,2

4,2

<
acrolein

2,5

<
phenol

0,6

acetylacetone

methods

(both colorimetric

2,4-dinitrophenylhydrazine Except

PRA

evap.

alcohol

acetaldehyde

studied.

HCHO)

MBTH

for

method

were

2-ethoxyethanol,

i0 % i n t e r f e r e n c e

with

these

and

the most

none

of the

fluorometric) specific

and

the

of the methods

compounds

tested

caused

two methods.

EXPERIMENTAL

Reagents:

All

or a n a l y t i c a l made

according

the

reagents

grade.

The

were

commercially

chemosorbent

to Andersson

et al 9.

tubes

available for t h e

pro-analytical

2,4-DNPH

on

concentration

i0 % i n t e r f e r e n c e

(interferent:

CTA n o evap.

over

contains

error

compound.

TABLE

The

24206)

the methods.

that had

assumption

2-ethoxyethanol

impurity,

o f all

ratios

of t h e

that

as a n

method

were

525

Instruments:

The c o l o r i m e t r i c

spectrophotometer fluorometer

determinations (water

syringe

were

formaldehyde) diluted

Three

sample,

were

duplicate

performed

been

determinations

according

to the

5000 HPLC with

was

to w h i c h

(corresponding

spectro-

measurements. a isocratic

HPLC

eluation

injected a known

by m i c r o l i t e r

concentration

to 1 p p m HCHO in the air

The mole

Some c o m p o u n d s

Bowman

1800

4020 UV-detector.

compounds

3 liter).

with

An A m i n c o

fluorometric

solutions

added

or 5:1.

(acrolein

done b y a Pye U n i c a m

a Pye U n i c a m

of o r g a n i c

DNPH w i t h

I00:i

with water

Model

with

amount

for the

or d e s o r p t i o n

had a l r e a d y

a 15 liter

used

done by a V a r i a n

A certain

were

a i0 m m autocell.

70) e q u i p p e d

into a b s o r p t i o n

formaldehyde

with

with

i0 m m cells was

30/methanol

Test p r o c e d u r e :

of

equipped

with

measurements

ratios

(test compound:

(added in ratio

5:1)

were

first

ethanol).

were made

instructions

in each

case.

specified

The a n a l y t i c a l

in the r e f e r e n c e s

stage was (Table

I).

REFERENCES

i. J. Skare,

B. Dahlner,

2. C. W. Lee, 3. C.E.

Y.S.

Bricker,

4. P. Bisgaard, dehyddampe

Arbete

Fung,

W.V.

och H~isa,

1973:6.

K.W.

Fung,

Analyst

Aubrey,

Anal.

Chem.

L. M~lhave,

i arbejds-

B. Rictz,

(In Swedish)

107:30

22:720

(1982).

(1950).

P. Wildharclt,

og opholdsrum,

M~ling

af formal-

Arbejdsmilj~fondet,

Copenhagen

1982.

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Miksch,

D.W.

J. Glanville, 6. R.R. 7. E.

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Sawicki,

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Anal. D.W.

C.R.

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Nilsson,

i0. L i n s t e d t

Chem.

Sawicki, London

et al,

Unders~kningsrapport ii.

Standard

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av f o r m a l d e h y d

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1981.

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Standardisation

(In Swedish). m~ritys

Association.

1978.

Instruments

APHA

Hollowell,

(1981).

Ind.

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G.D.

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Levin,

7:282

Fanning,

53:2118 Am.

C. Hallgren,

Health G.,

L.Z.

Anthon,

J-O.

9. K. Andersson, Environ.

Anthon,

at Work, Commitee,

Interdisplinary

in The N e t h e r l a n d s

Number

LC 132.

Methods

Books

for Air

Varian

Sampling

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14 F e b r u a r y

1984;

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