exempt paint

8/3/2019 Exempt Paint

1/6

Analysis of Exempt PaintSolvents by Gas ChromatographyUsing Solid-Phase MicroextractionRosem arie R, Bodrian, Albert C, Censullo, D an e R, Jones, Mark J, Rashkin, and Ma x T, Wi lls *-Golden Gate Society for Coatings Technology Technical Commibee

Acetone, met hyl acetate, and parachlorobenzotrifluoride (PCET F or OxsoI 100) have been exempted as VO C solvents b y the U.S.Envir onment al Protection Agency. ~n measuring coating VO C content, separate methods for d eterminin g exe mpt solvents are required.One such method utilizes solid-phase microextraction ( S PM E ) to sample the headspace of soIvent-based coatings to which the surrogatesacetone d6, methy l acetate d3, and~or metachIorobenzotrifluoride have been added. The sampled exe mpt coating so lvents are ther mall ydesorbed and analyzed using gas chromatography with flame ionization or mass spectral detection. The SPME headspace method hasalso been used to analyze M E K but yl acetate, tort- butyl acetate, toluene, and xyle ne in solventborrze coatings, an d alcohols inwaterborne systems. This paper presents the results obtained for acetone and toluene in a large numbe r o f aerosoI paints. Add itionally,the res ults fr om a round rotn'n stu dy fo r acetone, meth yl acetate, and parachlorobenzotrifluoride in commercial s olvent based coatingsare reported.

I N TRODUCT IONAc e t o n e , m e t h y l a c e t a te , a n d p a r a c h l o r o -b e n z o t r i f l u o r i d e ( PCBTF) h a v e b e e n e x -e m p t e d a s v o l a t i l e o r g a n i c c o m p o u n d(VOC) coa t ings so lvent s and are not inc l u d e d i n t h e m e a s u r e m e n t o f c o a t i n gVOC c o n t e n t. A s e p a r a t e m e t h o d f o r t h ed e t e r m i n a t i o n o f e x e m p t s o l v e n t s m u s tt h e r e f o r e b e c a r r i e d o u t wh e n VOC i sd e t e r m i n e d b y EPA M e t h o d 241 ( ASTMPract ice D 39602). As of D ece mbe r 4,1997,t h e EPA h a s r e c e i v e d p e t i t i o n s r e q u e s t-ing V9 exem pt s t a tus for t e r t -b uty l ac-e ta te ,3 d i m e t h y l s u c c i n a t e a n d d i m e t h y lg l u t a r a t e , 4 1 b r o m o p r o p a n e , s a n d o t h e rs o l v e n t s n o r m a l l y n o t u s e d i n c o a t i n g s .As e a c h n e w s o l v e n t i s a p p r o v e d a n df i n d s u s e i n c o a t in g s , th e VOC d e t e r m i -n a t i o n b e c o m e s e v e r m o r e c o m p l e x s i n c ee a c h o f t h e e x e m p t s o l v e n t s r e q u i r e s au n i q u e m e t h o d o f m e a s u r e m e n t . Gasc h r o m a t o g r a p h y a p p e a r s t o be t h e o n l ym e t h o d c u r r e n t l y a v a i l a b l e f o r c a r r y i n go u t t h e d e t e r m i n a t i o n o f i n d i v i d u a l s o lv e n t s .

I t h a s b e e n s h o wn t h a t t h e s p e c i a t e da n d t o t a l VOC c o n t e n t o f wa t e r b o r n ep a i n t s m a y b e d e t e r m i n e d b y d i re c t inj e c t io n i n t o a g a s c h r o m a t o g r a p h . 6 Th er e s u l t s o b t a i n e d we r e g e n e r a l l y g o o d ,a n d t h e m e t h o d u s e d i s p a r t i c u l a r l y e f-fec t ive for ana lyz in g low V9 contentc o a t i n g s . D i r e c t g a s c h r o m a t o g r a p h y o fwh o l e p a i n t s h a s a l so b e e n u s e d t o s t u d y*Department of Chemidw. Cali fornia PolytechnicState U niversity, San Luis Obispo, CA 93407

b o t h s o l v e n t b o r n e 7 a n d wa t e r b o r n e c o a ti n g s t o o b t a i n i n f o r m a t i o n o n h a z a r d o u sa i r p o l l u t a n t s ( HAPs ) u s i n g EPA M e t h o d311. 8 The resul t s o bta in ed in an ASTMi n t e r l a b o r a t o r y s t u d y o f EPA M e t h o d3 11 i n d i c a t e d t h a t t h e p r e c i s i o n wa s g e n -e r a l l y p o o r . 9 Th e d i r e c t q u a n t i t a t i v e g a sc h r o m a t o g r a p h i c a n a l y s i s o f v o l a t i le s o l -vent s in coa t ings i s of ten d i f f icu l t due tot h e r e l a t i v e l y c o m p l e x n a t u r e o f m o s tc o a t i n g s m a t r i x e s. Th e n o n v o l a t i l e c o r np o n e n t s p r e s e n t i n m a n y c o a t i n g s o f t e nm a k e i t d i f fi c u l t t o o b t a i n h o m o g e n e o u ss o l u t i o n s / d i s p e r s i o n s w i t h d i l u t i n g s o l-v e n t s. W h e n c o a t h G s s o l u t i o n s / d i s p e r -s ions a re in jec ted onto a gas chromato-g r a p h i c c o l u m n , d e c o m p o s i t i o n o f t h en o n v o l a t i l e c o m p o n e n t s m a y o c c u r in ah e a t e d i n j e c t i o n p o r t g e n e r a l l y m a i nt a i n e d a b o v e 2 40 ~ g i v i n g u n w a n t e dc h r o m a t o g r a p h i c s i g n a l s a n d p o s s i b l yr e s u l t i n g i n f o u l i n g o f e x p e n s i v e a n al y r i ca l s y s t e m s a n d c o l u n ~ s . An a l y t i c a lp r e c i s i o n is o f te n c o m p r o m i s e d a n d t i m ei s o f t e n wa s t e d i n r e s t o r i n g a n a l y s i s c a -p a b i l i t i e s .

Fo r s o l v e n t b o r n e s y s t e m s we h a v ed e v e l o p e d a u n i q u e d i s t i l l a t io n m e t h o df o r q u a n t i t a t i v e l y s e p a r a t i n g v o l a t i l ec o m p o n e n t s f r o m n o n v o l a t i l e c o m p on e n t s ) ~ Th e m e t h o d i s a m o d i f i c a t i o n o fASTM M e t h o d D 3 2 72 , " Va c u u m Di s t i ll a t i o n o f So l v e n t s f r o m So l v e n t - Re d u c -ib le Pa in t s for Analys i s . " ~ I n t h e m o d i -f i c a t i o n , a o n e - o r t wo - g r a m s a m p l e o ft h e c o a t i n g is m i x e d wi t h 5 m L o f d i o c t y lphtha la te (d i -2-e thylhexylphtha la te ) andt wo g r a m s o f t e t r a d e c a n e . Th e m i x t u r e

i s t h e n v a c u u m d i s t i l le d , a n d t h e d i s t i ll a t e i s t r a p p e d i n l i q u i d n i tr o g e n . Th en o n v o l a t i l e d i o c t y l p h t h a l a t e s e r v e s a sa d i s p e r s i o n m e d i u m f o r t h e c o a t i n g , a n dt h e t e t r a d e c a n e s e r v e s a s a c h a se s o l v e n tf o r t h e c o a t i n g v o l a t i l e s d u r h G t h e d i s -t i l l a t io n . S in c e m o s t c o a t i n g s c o n t a i nv o l a t i l e s wi t h b o i l hG poh~ts be lo w tha to f t e t r a d e c a n e , d i s t i l l a ti o n o f a p o r t i o no f th e t e t r a d e c a n e a l l o ws q u a n t i t a t i v et r a n s f e r o f t h e c o a t i n g s v o l a t i l e s t o t h el i q u i d n i tr o g e n t r a p . I n a d d i t i o n , th e t e r np e r a t u r e d u r i n g v a c u u m d i s ti l la t i on isnot a l lowed to exceed 110~ thus mini -m i z h G p o t e n t i a l n o n - v o l a t i l e d e c o m p o -s i t i o n a n d a p p r o x i m a t i n g t h e s a m e t e m -p e r a t u r e u s e d d u r i n g d e t e r m i n a t i o n o ft h e c o a t i n g v o l a t i l e c o n t e n t b y ASTMMe tho d D 2369.12 The d ist i l la te is gaschr om ato gra phe d on both a 100 m 0 .25m m p o l y d i m e t h y l s i l o x a n e a n d 6 0 m x0 . 2 5 m m Ca r b o wa x TM c a p i l l a r y c o l u m na n d q u a n t i t a t i v e l y s p e c i a t e d a f t er d e t e r -ru ina t ion of re la t ive respons e fac tors fore a c h a n a l y t e p r e s e n t h~ t h e s a m p l e . Af -t e r d e t e r m i n a t i o n o f t o t a l v o l a t i l e c o n -tent by ASTM D 2369, absolu te amou ntso f e a c h a n a l y t e m a y b e d e t e r m i n e d . A1t e r n a t i v e l y , a n i n t e r n a l s t a n d a r d c a n e a si l y b e i n c o r p o ra t e d p r i o r t o t h e v a c u u md i s t i l l a t io n a n d t h e n u s e d t o d e t e r m i n ea b s o l u t e a m o u n t s o f e a c h a n a l y t e . Th i sm e t h o d h a s b e e n u s e d t o a n a l y z e t h el i q u i d c o a t h G p o r t i o n o f m o r e t h a n 4 0dive rse so lven tborn e a erosol pah~ts . 13

A m e t h o d w a s n e e d e d t o v a l i d a te th er e s u l t s o b t a i n e d b y v a c u u m d i s t i l la t i o ng a s c h r o m a t o g r a p h y a n d s i n c e a l a r g e

Vol. 72, No. 900, January 200 0 69


2/6

Golden Gate Society Technical Committee

n u m b e r o f t h e s a m p l e s c o n t a i n e d a c e to n ea n d / o r t o l ue n e , th e s e a n a l y te s w e r e d et e r m i n e d s e p a r a t e l y b y s o l i d p h a s e m ic r o e x t r a c t i o n ( S P M E ). T h e S P M Em e t h o d wa s f o u n d t o b e s i m p l e t o u s ea n d g a v e v e r y p r e c i s e r e s u l ts . W e h a v ee x t e n d e d t h e S PM E m e t h o d f o r t h ea n a l y s i s o f o th e r c o m m o n s o l v e n ts f o u n di n c o a t i n g s , i n c l u d i n g p a r a c h l o r o -ben zot r i f luor ide (PCBTF or Oxso l 100) ,x y l e n e , m e t h y l e t h y l k e t o n e , b u t y l a ce t a te , t e t i a r y b u t y l a c e t a te , m e t h a n o l ,e t h a n o l , a n d 2 p r o p a n o l . A r o u n d r o b i nSPM E s t u d y wa s c o n d u c t e d f o r t h e s o l -v e n t s a c e t o n e , m e t h y l a c e t a t e , a n dPCBTF s in c e t h e s e h a v e b e e n e x e m p t e da s VOCs b y t h e U . S . En v i r o n m e n t a l P r o -t e c t io n A g e n c y . I n t h e r o m l d - r o b i ns t u d y , b o t h f l a m e i o n i z a t i o n d e t e c t i o n( S P M E / G C / F I D ) a n d m a s s s p e c tr a l d et e c t i o n ( S P M E / G C / M S ) w e r e u s e d t om e a s u r e a n a l y t e c o n c e n t r a ti o n s .

S P M E w a s i n i t i a ll y d e v e l o p e d b yJanusz paw l i sz yn 14-16 a t the Univ ers i tyo f W a t e r l o o , On t a r i o , Ca n a d a a n d i n -v o l v e s t h e e x t r a c t i o n o f a n a l y t e s f r o m al i q u i d h e a d s p a c e o r f r o m a n a q u e o u s

solu t ion onto a coa ted f iber . The SPMEfiber cons i s t s of a sec t ion of fused s i l ca ,c o a t e d wi t h a n a p p r o p r i a t e a d s o r b e n t ,wh i c h i s a t t a c h e d t o a m o d i f i e d GC s yr i n g e . I n u s i n g t h i s m e t h o d f o r d e t e rm i n i n g p a i n t s o l v e n t s , a s a m p l e o f p a i n ti s we i g h e d i n t o a s e p t u m - c a p p e d v i a lc o n t a i n i n g a d i s p e r s i o n m e d i u m o fd i c o c t y l p h t h a l a t e ( s o l v e n t b o r n e p a i n t )o r s a l t s o l u t i o n ( wa t e r b o r n e p a i n t ) . De -p e n d i n g o n t h e a n a l y t e o f i n t e r e s t , a na p p r o p r i a t e s u r r o g a t e i s we i g h e d i n t ot h e v i a l a n d t h e m i x t u r e i s a g i t a t e d a n da l l o we d t o e q u i l i b r a t e . Th e h e a d s p a c ea b o v e t h e s o l u t i o n i s s a m p l e d wi t h a nS P M E f i b e r a n d t h e n d e s o r b e d i n ah e a t e d GC i n l et o n t o a c a p i l l a r y c o lu m n .A f iber coa ted wi th a 65 b tm f i lm ofCa r b o w a x - d i v i n y l - b e n z e n e wa s u s e d f o ra l l a n a l y t e s s t u d i e d . A d i a g r a m f o r t h ee x p e r i m e n t a l e x t r a c t i o n s e t u p i s s h o wnin Figure 1.

One of the mos t s igni f i cant charact e r is t i c s o f t h e h e a d s p a c e SPM E m e t h o di s t h a t t h e a m o u n t o f e a c h a n a l y t e e xt r a d e d b y t h e f i b e r i s n o t p r o p o r t i o n a lt o th e a m o u n t o f t h a t a n a l y t e p r e s e n t i nt h e h e a d s p a c e . A n e q u i l i b r i u m i s e s t a b -l i s h e d b e t we e n t h e a m o u n t o f a n a l y t e i nt h e h e a d s p a c e a n d t h e a m o u n t o f a n a l y t ea d s o r b e d o n t h e f i b e r. La r g e r m o l e c u l e sa r e a d s o r b e d m o r e s t r o n g l y t o th e f i b e rr e s u l t i n g i n p r e f e r e n t i a l a d s o r p t i o n t othe f iber. Thi s e f fec t i s i l lus t ra ted in Fi gur e 2 for equal masses of ace tone , met h y l e t h y l k e to n e , m e t h y l p r o p y l k e t o n e ,m e t h y l i s o b u t y l ke t o n e, a n d m e t h y l a m y lk e t o n e d i s p e r s e d i n d i o c t y l p h t h a l a t e .T i l e h e a d s p a c e o f t h i s k e t o n e m i x t u r ewa s s a m p l e d u s i n g b o t h a g a s t i g h t s yr i n g e a n d a n SPM E s y r i n g e a n d i n j e c t e d /d e s o r b e d o n t o a g a s c h r o m a t o g r a p h . Th er e s u l t i n g r e l a t i v e p e a k a r e a s , a s t h e m ol e c u l a r w e i g h t i n c r e as e s , w e r e100:32:11:5 :1 wh en sam ple d by ga s- t ightsyr inge and 100:104:118:101:82 whensampled by SPME. Ti le same ef fec t waso b s e r v e d f o r a m i x t u r e o f m e t h y l a c -e ta te , e thyl ace ta te , and buty l ace ta te .Ga s 4 i g h t s y r i n g e s a mp l i n g g a v e a n a r e a r at i o o f 1 0 0 : 4 9 : 8 a n dSPM E s a m p l i n g g a v ea n a r e a r a t i o o f1 0 0 : 1 1 2 : 1 9 0 . W h e ns a m p l i n g t h e h e a d -space of a pa in t , h ighb o i l i n g s o l v e n t s , e v e nw h e n p r e s e n t in v e r yl o w c o n c e n t r a t i o n i nt h e h e a d s p a c e , a r ep r e f e r e n t i a l l y a bs o r b e d o n t o a n SPM Ef i b e r r e l a t i v e t o am u c h h i g h e r h e a d -s p a c e c o n c e n t r a t i o n o fa l o w m o l e c u l a rwe i g h t m a t e r i a l .

T h e a n a l y te s a n d c o r r e s p o n d i n g s u >r o g a t e s s t u d i e d , a s w e l l a s t h e i r b o i l i n gp o i n t s , a re s h o wn i n TabIe 1. In al l cases,e x c e p t p a r a c h l o r o b e n z o t r i - f l u o r i d e , b u -ty l ace ta te , and t e r t -buty l ace tate , the sur -r o g a t e wa s a d e u t e r a t e d a n a l o g o f t h ea n a l y t e . Su r r o g a t e s we r e c h o s e n b a s e don the fo l lowing cr i t e r i a :(1) The boi l ing poin t i s near ly thes a m e a s t h e c o r r e s p o n d i n g a n a l y t e ;(2) The s t ruc ture i s s imi la r to tha t oft h e c o r r e s p o n d i n g a n a l y t e ;( 3) GC p e a k s e p a r a t i o n f r o m t h e c o r -r e s p o n d i n g a n a l y t e o c c u r s ; a n d(4) I t i s not a co mpo nent of the pa in ts a m p l e b e i n g a n a l y z e d .

EXPER IMENTALTi l e f o l l o wi n g i s a d e t a i l e d p r o c e d u r efor the ana lys i s of ace tone , methyl ace t a t e , a n d p a r a c h l o r o b e n z o t r i f l u o r i d e( PCBTF) i n s o l v e n t b o m e c o a t i n g s u s i n ge i th e r S P M E / G C / f l a m e i o n i za t i o n d et e ct i on o r S P M E / G C / m a s s s p e c tr a l d et e ct i o n. T i le s a m e p r o c e d u r e m a y b e u s e df o r o t h e r a n a l y t e s in s o l v e n t b o r n e p a i n t sb y i n c o r p o r a t i n g t h e a p p r o p r i a t e i n t e r-n a l s t a n d a r d a s i n d i c a t e d in Table 1.APPARATUS AND REAGENTS:1 .1 M a n u a l SPM E h o l d e r f it t e d wi t h aC a r b o w a x / D i v i n y l b e n z e n e ( C W /DVB) f iber ass emb ly , 65 ~tm f i lmt h i c k n e s s , p a r t i a l l y c r o s s l i n k e d( Su p e lc o ) wa s u s e d .1 .2 G a s C h r o m a t o g r a p h , F I D D e t e ct i o n: A n y c a p i l l a r y g a s c h r o m a t o -g r a p h e q u i p p e d w i t h a f l a m e i o n -

i z a t i o n d e t e c t o r m a y b e u s e d .T e m p e r a t u r e p r o g r a m m i n g c a p a -b i l i t y is d e s i r a b l e , b u t i s o t h e r m a lo p e r a t i o n s m a y b e u t i l i z e d .1 .2 .1 FID Ins t ru men t Cond i t ions :D e t e c t o ~ F l a m e i o n i z a t i o nCo lum n 60 m x 0 .25 ram DB Wax(J&W Scient i fi c Co.) or equi valent , 0.5 btln f ihn thi ckn ess.C a r ri e r G a s - - H e l i u mFl o w Ra t e - - 1 . 0 m L p e r r a i n ( 20 c mper sec)Spli t Rari ty--200 to 1F i b e r De s o r p t i o n T i m e ~ t o 6 s e cTe m p e r a t u r e s , ~

Inlet 260 ~D e t e c t o r 2 7 0 ~Ini t i a l - -35 ~ for 12 ra inRate 1- -30 ~ per ra in to 100 ~hold 10 ra inRate 2- -30 ~ per ra in to 240 ~h o l d 2 r a i n1 .2 .2 . - -A 0 .75 mm in le t l iner sho uld bep l a c e d i n t h e i n j e c t i o n p o r t .1 . 2 . 3 . - - I n t e g r a t o r - - An y e l e c t r o n i c i n t e -g r a t o r t h a t c a n a c c u r a t e l y q u a n t i f y ag a s c h r o m a t o g r a p h i c p e a k a r e a i s a na c c e p t a b l e i n t e g r a t o r .

70 Jour na l f Coatings Technology


3/6

A n a l y s i s o f E x e m p t P a i n t S o l v e n t s1.3 Gas Chr oma tog rap h, Mass Selecrive (MS) Detection: Any capilla ry gaschromatograph equi pped with a massselective detector may be used. Thedetector must be capable of measur-ing in the selected ion monitoring(SIM) mode at dwe ll times of 100 railliseconds or less.1.3.1 MS Inst rume nt Conditions:

Detector--Electron ionization or massselectiveDetection Mode--SIM of ions m/ e58, 64, 74, 77, and 180Dwell Time 100 milli seco nds or lessSolvent De la y0. 0 rainCol umn 25 m x 0.20 mm HP 6(Hewlett Packard Co.) or equi-vale nt, 0.11 gin f ilm thicknessCarrier Gas--- HeliumFlow Rate--1.0 mL per rain (20 cmper sec)Split Ratio 200 to 1Fiber Desorption Tim e~ to 6 secTemperature, ~Inle t 260 ~Detector--280 ~Ini t ial~40~ for 2 ra inRate 1--10 ~ per rain to 90 ~hold i rainRate 2---40~ per rai n to 240 ~hold 1 rain1.3.2--A 0.75 mm inlet liner should beplace d At the inject ion port.1.3.3--The instrument should have asoftware data syste mto allow extrac-tion and integratio n of the SIM ions.1.4~R equi red reagents include: Acetone-d6, 99.9% isotopic purit y; met hyl ac-

etate -d3, 99.9% isotopic purity;para chlo robe nz otriflu oride (PCBTF),technical grade, 99+% was obtainedfrom the Occidental Chemical Corporat ion and has the t rade nameOxsol ~ 100; metachlorob enzotriflu o-ride (MCBTF), 97%.PREPARATION OF STANDARDS:2.1--Place 6 mL dioctyl phthalat e into a22 or 40 mL vial and seal with a sep-turn cap.2.2--Using dedicated 250 gL syringes,weigh ap proxim ately 100 mg each of

parachlorobenzotrifluoride and metachlorobenzotr ifluoride to 0.1 mg intothe vial. Excess solvent should bewiped from the syringe needle priorto piercing the septum. A ny solventadherh G to the outside of the sep-turn cap after making the transfershould be wiped off with tissue.Weigh the amounts of PCBTF andMCBTF to 0.1 rag. Repe at the procedure by adding approximately 150mg each of acetone, acetone d6, methyl acetate and methyl acetate d3and we igh each compon ent to 0.1 rag.

T a b l e I - - A n a l y t e s a n d C o r r e s p o n d i n g S u r r og a t esA n al yt e, b.p . ~ .. .. . .. . . .. . .. . .. . . .. . .. . .. . .. . . .. . .. . .. . . .. . . Su rr og at e, b. p. ~A c e to n e , 56.0 .. .. . . .. . .. . .. . .. . . .. . .. . .. . . .. . .. . .. . . .. . .. . .. . . A c e to n e -d 6 , 55.5M eth yl e thy l ke to ne , 80 . .. .. . .. .. .. .. .. . .. .. .. .. .. . .. .. . 2 Bu la no ne 1,1,1,3,3 d 5Parachlorobenzotrifluoride, 136-138 . .. .. .. .. .. . 3 -C h lo r obe nzo t r i f l u o r id e , 137 -138M e t h y l acetate, 57.5 ... .. . .. . .. . . .. . .. . .. . .. . . .. . .. . .. . . . M et hy l dO a c e t a t e d3, 57. 0tert -B uly l a ce ta te , 98 . . .. .. .. .. .. . .. .. .. .. .. . .. .. .. .. .. . .. M et hy l h i m et h yl a ce ta te , 101B u M acetate, 124 126 ................................... M e th yl valerate, 12 8To lue ne , 110.6 .... . . .. . .. . .. . .. . . .. . .. . .. . . .. . .. . .. . . .. . .. . .. . . To lu en e- d8 , 1 1 0X yl en e, 137 144 .... . .. . . .. . .. . .. . . .. . .. . .. . .. . . .. . .. . .. . . .. . .. E lh yl be nz en e d l0 , 134 .6p - X y l e n e - d l G 1 3 5o X y l e n e d l O , 1 4 2M et h an ol , 64.7 .. .. . . .. . .. . .. . .. . . .. . .. . .. . . .. . .. . .. . .. . . .. . .. . M e th an o l- d 3, 65. 4Et ha no l, 78 ....................................................... E th an ol d5 , 782- Pr op an ol , 82.4 .. .. . .. . . .. . .. . .. . . .. . .. . .. . .. . . .. . .. . .. . . .. . . 2- Pr op an ol -d 7, 82

2.3- -Man uall y shake the vial for 15 secto mix the content and then let thevial stand at roomtemper ature for30rain.2.4 Remove the cap and wipe the septurn to remove solvent from the inner surface and reseal immediately,or replace the septum with a new

o n e .

2.5 Sample the headspace with theSPME fiber for 60 sec.2.6- -De sorb the SPME fiber for 5 to 6 secin the injection port of the gas chro-matograph us ing either the conditionsdescri bed i n 1.2 or 1.3.2.7--C lean the fiber by placffG it in theGC injec tion port for 15 sec after theanalytes of interest have passedthrough the capillary column.2.8 If usin g the GC/FI D procedure,

measure the peak areas of the threeanalytes and three standards by integrat ion . Curve f i t t ing sof tware(GRAMS/32, Galactic Industries) formeasuring peak areas is advanta-geous in some instances.2.9--If usffG the GC /MS procedure,measure the peak areas for the ex-tracted ions as follows: analyte, m/e ,retention time in minutes; acetone,58, 1.26; acetone d6, 64, 1.26; methylacetate, 74, 1.34; methyl acetate d3,77, 1.34; MCBTF, 180, 4.84; PCBTF,180, 4.90.2.10 Calculate respo nse factors (RF) foracetone, methyl acetate, and PCBTFaccordffG to the equa tion given insection 3.4. The numerical valuesshould agree withi n 1% of each other.PAINT ANALYSIS:3.1~eigh 0 .5 t o 1.0 g of well mixedpaint into a septum capped vial conrainin g 6 mL of dioctyl phthalat e using a disposable 1 mL syringe. Thepaint should drop directly into thedicoctyl phthalate . Carr y out the sameprocedures as described in 2.3 to 2.7.

3.2--Determine which, if any, of thethree exempt solvents are present inthe paint sample and if interferingpeaks are present at the retentiontimes corresponding to the retentiontimes of the internal standards.3 . 3 ~e i g h to 0.1 rag, 0.5 to 1.0 g ofpaint sample and 100 mg of each ofthe internal standards, corresponding to the analytes found in 3.2, into asep tum -ca ppe d vial contafftff G 6 mLdioctyl phthalate. Car ry out the sameprocedure as described in 2.3 to 2.9.3. 4~ al cu la te analyte concentrations ac-cording to the following equations:

A A ,~ M I A A ~ M I * I O 0R F - a n d % A n a l y teAI * MA AI * RF 9 M Cwhe re RF = Respon se factorAA = Area of analyte

MI = Mass of intern al stan dardAI Area of internal standardMA Mass of analyteMC Mass of coating3.5 Repeat the proced ure given in section 3.3 usingpa int and internal standard amounts such that the relativepeak areas of the analyte and its fit-t ernal s tandard chromatographicpeak areas are approx imately thesame size. A duplic ate injection ofthe same sample shou ld give relativepeak areas which agree within onepercent of each other.

R E S U L T SA e r o s o l C o a t i n g s

In the course of a study of more tha n 40diverse solv entb ome aerosol paints, thepropellant front each was transferred toa gas sampling bag, and the remai ningl iquid coat ing was d i s t i l l ed undervacuum to separate the volatiles andnon volatiles. The volatile portion wasgas chromatographed to give the speciated profile of the volatile compounds

V o l . 7 2 , N o . 9 0 0 , J a n u a r y 2 0 0 0 7 1


4/6

G o l d e n G a t e S o c i e t y T ec h n i c a l Co mmi t t e e

for each coating. SPME/GC/FID wasused to validate the results obtained foracetone and/or toluene in 23 of theseaerosol coatings. A compariso n of thesetwo en tirely different methods indicatethat both methods gave very good re-sults (Table 2). Of 18 samples wh ich conrained acetone, the average differencebetw een the two me thods wa s 0.52%. Of10 samples which contai ned toluene, theaverage difference between the twomethods was 1.16%. Based on these re-sults, it was bel ieved that the SPME /GCmethod could serve as a simple and clean

method for quantifying exempt andother ind ivid ual solvents in coatings.R o u n d - R o b i n A n a l y s i s o fC o a t i n g s ContainingE x e m p t

S o l v e n t sA round robin was conducted involvh~g five laboratories. The laboratoriesparticipathG in the rotund-robin wereexperienced in both gas chromatogra-phy and SPME methodology. All of thelaboratories used the SPME samplingtechnique. Three of the laboratories used

FID to measure analyte amounts, andtwo of the laboratories used MS detec-tion to measure analyte amounts.Six commercial solventborne coatings were analyzed. Four of the coatings contained acetone and two of thesame four coatings contai ned both acetone and parachlorobenzotrifluoride.Coatin gs contah~hG methyl acetate werenot yet available in the marketplace

whe n this rom~d-robh~ was carried outand were, therefore, prepared by add-ing known amounts of methyl acetateto different cellulose nitrate lacquers.Four of the six coatings were nitr ocellulose lacquers obtained from two different manufa cture rs. Two of the six coathGs were parts of a two-compon ent pig-mented primer which were analy zed astwo separate coatings. A typical FIDchromatogram of a nitrocellulose lac-quer contain ing acetone, added methylacetate, added PCBTF, and the appropriate internal standards is shown inFigure 3.Precision data was calculated separarely for the three laboratories usingFID and the two laboratories ushG MSdetection and also for the combinationof FID and MS detection. Average val-ues, repeatability standard deviations(Sr), reproducib ility standa rd deviations(SR), repeat abili ty at the 95% confid encelimit (r), and reprod ucibility at the 95%confidence limit (R) are given for eachcoating and exempt solvent in Tables 3and 4.

Table 2--Co mpa rison of SPME and DistillalJon Results for Ac eto ne and Toluene% Acelone

Sample SPM E Distillation Error= SPME/Distb SPME% TolueneDistillation Error= SPMI:/DJsl

27 . . . . .. . . . . .. . . . . .. . . . . 28 .5 3 27 . 12 1 .41 1 .05 34 .9 7 36 .4 3 1 .46 0 .9 62 9 ... .. . . . . . . . . . . . .. . . . . 7 1 . 8 7 7 2 . 2 8 0 .41 0 . 9 9 . . . .3 4 . . .. . .. . .. . .. . .. . .. . .. 4 2 .8 3 4 1 .7 1 1 .1 2 1 .0 3 4 0 .4 9 4 2 .1 7 1 .6 8 0 .9 63 5 ... .. . . . . . . . . . . . .. . . . . 5 1 . 5 5 5 2 . 3 9 0 .8 4 0 . 9 8 . . . .36 . . . . .. . . . . .. . . . . .. . . . . 11 .18 9 .47 1 .71 1 .183 7 . . .. . .. . .. . .. . .. . .. . .. - - - - - - - - 2 7 .7 5 2 8 .4 8 0 .7 3 0 .9 738 . . . . .. . . . . .. . . . . .. . . . . 38 .7 3 38 . 84 0 .11 1 .003 9 ... .. . . . . . . . . . . . .. . . . . 5 5 . 6 2 5 6 . 0 0 0 . 3 8 0 . 9 9 . . . .41 . . . . .. . . . . .. . . . . .. . . . . 34 . 68 35 .4 7 0 .7 9 0 .9 84 2 ... .. . . . . . . . . . . . .. . . . . 4 0 . 2 8 3 9 . 6 5 4 3 .6 3 1 .0 2 . . . .43 . . . . .. . . . . .. . . . . .. . . . . 11 .57 11 .96 0 .3 9 0 .9 744 . . . . .. . . . . .. . . . . .. . . . . - - - - - - - - 13 .43 13 .82 0 .4 0 0 .9 74 5 . . .. . .. . .. . .. . .. . .. . .. 4 0 .6 8 4 0 .4 0 4 3 .2 8 1 .0 1 2 9 .8 7 3 0 .4 1 0 .5 4 0 .9 848 . . . . .. . . . . .. . . . . .. . . . . - - - - - - - - 38 . 92 38 . 85 43 .08 1 . IX ]49 . . . . .. . . . . .. . . . . .. . . . . 50 . 06 49 . 19 43 .87 1 .025 0 ... .. . . . . . . . . . . . .. . . . . 3 7 . 4 7 3 6 . 2 8 - 1 . 1 9 1 .03 . . . .51 . . . . .. . . . . .. . . . . .. . . . . 54 .2 4 53 . 23 1 .01 1 .025 7 ... .. . . . . . . . . . . . .. . . . . 4 8 . 9 3 49 .5 1 0 . 5 8 0 . 9 9 . . . .63 . . . . .. . . . . .. . . . . .. . . . . 56 . 82 54 . 85 1 .97 1 .046 4 . . .. . .. . .. . .. . .. . .. . .. 4 0 .3 6 3 9 .2 7 - 1 .0 9 1 .0 3 2 1 .6 0 2 1 .9 2 0 .3 2 0 .9 966 . . . . .. . . . . .. . . . . .. . . . . 69 . 33 68 .71 43 .6 2 1 .016 7 ... .. . . . . . . . . . . . .. . . . . 5 4 . 6 6 5 6 . 7 0 2 . 0 4 0 . 9 6 . . . .8 7 . . .. . .. . .. . .. . .. . .. . .. 1 3 .4 7 1 3 .6 2 0 .1 5 0 .9 9 6 7 .0 6 7 0 .6 6 3 .6 0 0 .9 5A vg . . . .. . . .. . . .. . .. . . . - - - - 4 3 .5 2 1 .0 2 - - - - 1 . 1 6 0 .9 7

(a) Difference between distillation nd SPME result.(b) Retie of compos ition as determine d by SPME relative to dis/il lotion procedure. This should equal exactly 1 00 if the two methods p rodu ced identical results

7 2 J o u r n a l o f C o a t i n g s T e c h n o l o g y


5/6


6/6

Golden Gate Society Technica l Com mit teeu s e d f o r d e t e r m i n a t i o n o f h a z a r d o u s a i rp o l l u t a n t s ( H A P s ) . A n i n t e r n a l st a n d a r dc a n e a s i l y b e i n c o r p o r a t e d p r i o r t o d i st i l l a t i o n , a n d t h e d i s t i l l a t e m a y b ec h r o m a t o g r a p h e d o n a n y s u i t ab l e ca p ril a r y c o l u m n w i t h o u t d i s r u p t i n g t h e int e g r i ty o f t h e c h r o m a t o g r a p h i c s y s t e mb e i n g u s e d .

A C K N O W L E D G M E N T ST h e a u t h o r s w i s h t o t h a n k D a r i c k X . D i n ga n d S a n t o s P . S a r ab i a , s t u d e n t s a t C a li -f o r n i a P o l y t e c h n i c S t a t e U n i v e r s i t y , S a nL u i s O b i s p o , f o r th e i r p a r t i c i p a t i o n i nt h i s p ro j e c t. T h a n k s a r e e x t e n d e d t o t h ef o l l o w i n g i n d i v i d u a l s f o r t h e i r p a r t i c ip a t i o n i n th e r o u n d r o b i n st u d y : R o b e r tS h i r e y , S u p e l c o , I n c . ; L o r r a i n e D a S i l v a ,P h i l i p A n a l y t i c a l C o m p a n y ; J o h nP h i ll ip s , F o r d M o t o r C o m p a n y ; D r . R o b -e r t A t h e y , A t h e y T e c h n o l o g i e s . W e a l s ot h a n k P a c i fi c C o a st L a c q u e r , A k z o C o a ti n g s , a n d U . S . C e l l u l o s e C o m p a n y f o rp r o v i d i n g s a m p l e s f o r t h e r o u n d r o b i ns t u d y .

References( 1) E PA R ef erence M e thod 24 , " De te r m inat i o n o f V o l a ti l e M a t t e r C o n t e n t , D e n s i t y ,V o l u m e S o l i d s , a n d W e i g h t S o l i d s o fS u r fa c e C o a t i n g s ." A v a i l a b l e f r o m S up e r i n t e n d e n t o f D o c u m e n t s , U . S . G o v -e r n m e n t P r i n t i n g O f f i c e , W a s h i n g t o n ,D. C . R ef er t o C FR 40 , Par t 60 , Ap pen d ixA .

(2) D 3960, " 'Pract ice for Dete rm inin g Volat i le O r g a n i c C o m p o u n d ( V O C ) C o n t e n to f Pa in t s and R ela t ed C oa t ings , " An n u a lBook of Starzdards, Vol . 06 .01 , Am er i ca nSoc ie ty f o r T es t ing and M ater i a l s , W es tC o n s h o h o c k e n , P A .( 3) A r c o C h e m i c a l C o m p a n y ( s u b m i t t e d t oU. S . E PA on 1 /17 /97) .( 4) Dibas i c E s t e r s Gr ou p , a f f il i a t ed wi th f f i eS y n t h e t i c O r g a n i c C h e m i c a l M a n u f a c -tu r e r s As s oc ia t ion , I nc . ( s ubmi t t ed toU. S . E PA on 1 0 /14 /97) .( 5) E nv i r o T ech I n t e r na t ion a l ,A l a m e d a , C A( s u b m i t t e d to U . S. E PA o n 5 / 1 0 / 9 6 ) . P e -t i t i o n a ls o s u b m i t t e d b y A l b e r m a r l eC o r p . , B a t on R o u g e , L A ( s u b m i t t e d o n1 1 / 1 8 / 9 7 ) .( 6) L os Ange les Soc ie ty f o r C oa t ings T ech-no logy , "'Dir ect VO C A nalys i s o f WaterB a s e d C o a t i n g s b y G a s C h r o m a t o g r a -p h y a n d S o l i d P h a s e M i c r o e x t r a c ti o n , "JOURNALOF COATINGS ECHNOLOGY, 9, N o.869, 33 (1997).( 7) D 3271 , " S tan dar d P r ac t i ce f o r Di r ec tI n j ec t ionof So lven t R e duc ib l e Pa in t s i n toa G a s C h r o m a t o g r a p h f o r S o l v e n t A n a l y -sis," Artrtual Book o f AST M Standards, Vol.06 .01 , Am er i ca n Soc ie ty f o r T es t ing an dM a t e r i a ls , W e s t C o n s h o h o c k e n , P A .( 8) E PA R ef er ence M e thod 311 , " An alys i so f H a z a r d o u s A i r P o l l u t a n t C o m p o u n d si n P a i n t s a n d C o a t i n g s b y D i r e ct I n je c -t i o n I n to a G a s C h r o m a t o g r a p h . " A v a i la b l e f r o m S u p e r i n t e n d e n t o f D o c u m e n t s ,U .S . G o v e r n m e n t P r i n t i n g O f f ic e , W a s hing ton , D. C . R ef er t o C FR 40 , Par t 63 ,A p p e n d i x A .( 9) R e s u l t s p r e s e n t e d b y S u b - C o m m i t t e eDO1.21.52, AST M M eet in g, June 26,1995,A t l a n t a , G A .( 10) C ens u l lo , A . C , Wi l l s , M . T . , and J ones ,D .R ., " I m p r o v e m e n t o f S p e c i a t i o n P r o -

f i l e s f o r A r c h i t e c t u r a l a n d I n d u s t r i a lM a i n t e n a n c e C o a t i n g O p e r a t i o n s , " F i -n a l R e p o r t t o t h e C a l i f o r n i a A i r R es our ces B oar d , J une 1996.( 11) D 3272 , " S tand ar d P r ac t i ce fo r Vac uumDis t i l l a t i on o f So lven t s f r om So lven t - R e-duc ib l e Pa in t s f o r Ana lys i s , " Annual Booko f AS T M S ta n da rds , Vol. 06.01, Ameri-can Soc ie ty f o r T es t ing and M ater i a l s ,W e s t C o n s h o h o c k e n , P A .( 12) D 2369 , " T es t M ethod f o r Vola t i l e C o nten t o f C oa t ings , " An n u a l Bo o k o f AS TMStandards, VoL 06 . 01 , Am er i can So c ie tyf o r T e s ~ g a n d M a t e r i a ls , W e s t C o n s h o -hocken , PA.( 13) C ens u l lo , A . C . , Wi l l s , M . T ., an d J ones ,D . K , " I m p r o v e m e n t o f S p e c i a t i o n P r of i l es f o r Aer os o l C oa t ings , " F ina l R epor tto t he C a l i f o r n i a Ai r R es our ces B oar d ,i n p r e p a r a t i o n .( 14) B oyd B oland , A. A. , C ha i , M , L uo , Y.Z . ,Zhang, Z. , Yang, M.J . , Pawliszyn, J .B. ,a n d G o r e c k i, T , " ' N e w S o l v e n t F r e eS a m p l e P r e p a r a t i o n T e c t m i q u e s B a s e don F iber and Po lym er T echno log ies ," Environ me ntd Science and Technology, 28,No. 13 , 569A ( Dece mber 1994) .( 15) Paw l i s zyn , J ., Solid Phase Microex traction,Wiley VC H , I nc . , 1997.( 16) A comp le t e l i s t o f J . Paw l i s zyn ' s SPM Ep a p e r s i s a v a i l a b l e o n t h e w o r l d w i d ew e b a t h t t p : / / s c i b o r g . u w a t e r l o o . c a /~ j a n u s z / s p m e p u b . h t m L( 16) E 180-94 , " P r ac t i ce f o r D ete r m in ing theP r e c i s i o n D a t a o f A S T M M e t h o d s f o rA n a l y s i s a n d T e s t i n g o f I n d u s t r i a lC hemica l s , " An n u a l Bo ok o f AS TM S ta r tdards , Vo l . 15 . 05 , Am er i ca n Soc ie ty f o rT e s t i n g M a t er i a ls , W e s t C o n s h o h o c k e n ,PA .

74 Jo urn al f Coat ings Technology

exempt paint

Documents