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• 10 •

800-356-1688 •

www.restek.com

2004 vol. 3

Convenient Calibration, Faster GC/MS

Analysis for Volatile Organics inWater

Using a New Restek Calibration Mix and an Rtx

-VMS Column

Volatile organic analytes (VOAs) are a common

source of environmental pollution, and are

among the most difficult and expensive contami-

nants to monitor in water. Analysis and quantifi-

cation of VOAs in drinking water are detailed in

US EPA methods 502 and 524, and in many other

methods worldwide.

Until now, Restek has offered two complex cali-

bration mixes of volatile compounds for drinking

water analysis: a mix containing 54 target com-

pounds (502.2 MegaMix

™

, cat.# 30432), and one

containing 73 compounds (Drinking Water VOA

MegaMix

™

524.2 Rev. 4.2, cat.# 30601). The only

target compounds in the EPA methods that we

do not include in these mixes are the highly

volatile gases, and, for Method 524.2, the reac-

tive ketones. To prevent acetal formation, we

offer the five ketones as a separate mix (cat.#

30602). We also offer the six gases separately,

as 502.2 Calibration Mix #1 (cat.# 30042 or

cat.# 30439). Analysts monitoring samples for

the gases combine the gases mix with either the

54-component mix or the 73-component mix—

this takes time and can introduce variation or

mixing errors.

For the convenience of our customers, we have

developed a new 60-component calibration mix

(Volatiles MegaMix

™

with Gases, cat.# 30603)

that contains the 54 target compounds in 502.2

MegaMix

™

mix, plus the six gases in 502.2

Calibration Mix #1, at 200 ppm each in purge

and trap methanol. The new mix is suitable for

Method 502, Method 524, or other methods fol-

lowed in monitoring these compounds.

The new mix brings a choice. The 60-component

mix is very convenient to use, and eliminates

both variation and the potential for errors

(associated with measuring and mixing from

multiple ampuls). An unopened ampul of this mix

has a 24-month shelf life, but once the ampul is

opened, the gases can begin to escape from the

solution, and opened ampuls of the new mix

should be replaced more frequently than ampuls

of the 54-component mix. (This also is true of

the 6-component gas mix.) Analysts choosing to

work with the 54-component mix and the six

gases mix must contend with the potential for

mixing errors, but can see longer lifetimes from

ampuls of the opened 54-component mix—if

they are stored properly. We recommend storing

all VOAs reference mixes in a freezer, especially

those containing the gases.

Chemists monitoring VOAs in water require fast

and accurate analyses. A chromatography col-

umn with a cyanopropylphenyl/dimethyl poly-

siloxane stationary phase (e.g., a “624” column)

or a diphenyl/dimethyl polysiloxane phase (e.g.,

a “502.2” column) can provide a fast analysis,

but some compounds are likely to coelute, creat-

ing quantification problems. In contrast, Rtx

VMS columns are designed specifically for

analyses of volatiles by GC/MS, and circumvent

such problems. Analysis on a 20m, 0.18mm ID,

1.0µm Rtx

-VMS column (cat.# 49914), using a

45ºC initial oven temperature, will provide good

resolution of the early eluting gases and ensure

faster oven cycles. Under optimized analytical

conditions and using a dual purge and trap sys-

tem, as shown in Reference 1, Figure 47, the

narrow bore column can reduce the analysis

time to approximately 10 minutes, without sacri-

ficing resolution.

If you are testing for volatiles in drinking water,

wastewater, or hazardous waste, an Rtx

-VMS

column and our new 60-component volatiles

MegaMix

™

with gases will help you meet the

requirements for most analytical methods.

Reference

Optimizing the Analysis of

Volatile Organic Compounds

Restek technical guide,

lit. cat.# 59887A,

free on request.

Also available on our website.

by Katia May, Ph.D., Senior R&D Chemist, and Jack Crissman, Ph.D., Analytical Reference Materials

Marketing Manager

• 60-component MegaMix

™

includes six target gases—eliminates mixing errors.

• 0.18mm Rtx

-VMS column offers fast cycles, excellent resolution of gases.

•Monitor drinking water - wastewater - hazardous waste.

benzene

bromobenzene

bromochloromethane

bromodichloromethane

bromoform

bromomethane (methyl bromide)

-butylbenzene

sec

-butylbenzene

tert

-butylbenzene

carbon tetrachloride

chlorobenzene

chloroethane (ethyl chloride)

chloroform

chloromethane (methyl chloride)

2-chlorotoluene

4-chlorotoluene

dibromochloromethane

1,2-dibromo-3-chloropropane

1,2-dibromoethane (EDB)

dibromomethane

1,2-dichlorobenzene

1,3-dichlorobenzene

1,4-dichlorobenzene

dichlorodifluoromethane (CFC-12)

1,1-dichloroethane

1,2-dichloroethane

1,1-dichloroethylene

cis

-1,2-dichloroethylene

trans

-1,2-dichloroethylene

1,2-dichloropropane

1,3-dichloropropane

2,2-dichloropropane

1,1-dichloropropene

trans

-1,3-dichloropropene

cis

-1,3-dichloropropylene

ethylbenzene

hexachloro-1,3-butadiene

(hexachlorobutadiene)

isopropylbenzene (cumene)

4-isopropyltoluene (

-cymene)

methylene chloride

(dichloromethane)

naphthalene

-propylbenzene

styrene

toluene

1,1,1,2-tetrachloroethane

1,1,2,2-tetrachloroethane

tetrachloroethylene

1,2,4-trichlorobenzene

1,2,3-trichlorobenzene

1,1,1-trichloroethane

1,1,2-trichloroethane

trichloroethylene

trichlorofluoromethane (CFC-11)

1,2,3-trichloropropane

1,3,5-trimethylbenzene

1,2,4-trimethylbenzene

vinyl chloride

-xylene

Volatiles MegaMix

™

with

Gases

(60 Components)

Each

5-pk.

10-pk.

200µg/mL each in P&T methanol, 1mL/ampul

30603

$85

30603-510

$382.50

—

w/data pack

30603-500

$95

30603-520

$392.50

30703

$722.50

Rtx

-VMS Columns (fused silica)

benzene

bromobenzene

bromochloromethane

bromodichloromethane

bromoform

-butylbenzene

sec

-butylbenzene

tert

-butylbenzene

carbon tetrachloride

chlorobenzene

chloroform

2-chlorotoluene

4-chlorotoluene

dibromochloromethane

1,2-dibromo-3-chloropropane

1,2-dibromoethane

dibromomethane

1,2-dichlorobenzene

1,3-dichlorobenzene

1,4-dichlorobenzene

1,1-dichloroethane

1,2-dichloroethane

1,1-dichloroethene

cis

-1,2-dichloroethene

trans

-1,2-dichloroethene

1,2-dichloropropane

1,3-dichloropropane

2,2-dichloropropane

1,1-dichloropropene

cis

-1,3-dichloropropene

trans

-1,3-dichloropropene

ethylbenzene

hexachlorobutadiene

isopropylbenzene

-isopropyltoluene

methylene chloride

naphthalene

-propylbenzene

styrene

1,1,1,2-tetrachloroethane

1,1,2,2-tetrachloroethane

tetrachloroethene

toluene

1,2,3-trichlorobenzene

1,2,4-trichlorobenzene

1,1,1-trichloroethane

1,1,2-trichloroethane

trichloroethene

1,2,3-trichloropropane

1,2,4-trimethylbenzene

1,3,5-trimethylbenzene

-xylene

502.2 MegaMix

™

(54 Components)

Each

5-pk.

10-pk.

200µg/mL each in P&T methanol, 1mL/ampul

30432

$56.70

30432-510

$249.70

—

w/data pack

30432-500

$67

30432-520

$277.10

30532

$484.20

2,000µg/mL each in P&T methanol, 1mL/ampul

30431

$78.30

30431-510

$348.20

—

w/data pack

30431-500

$88.60

30431-520

$386.80

30531

$676

bromomethane

chloroethane

chloromethane

dichlorodifluoromethane

trichlorofluoromethane

vinyl chloride

502.2 Calibration Mix #1 (gases)

Each

5-pk.

10-pk.

200µg/mL each in P&T methanol, 1mL/ampul

30439

$23.70

30439-510

$103.60

—

w/data pack

30439-500

$34

30439-520

$114.70

30539

$201

2,000µg/mL each in P&T methanol, 1mL/ampul

30042

$34

30042-510

$151.30

—

w/data pack

30042-500

$44.30

30042-520

$167.50

30142

$292.40

(temp. limits -40°C to 240/260°C)

0.18mm ID, 1.00µm df

20-Meter, cat.# 49914,

$375

40-Meter, cat.# 49915,

$650