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Procedure B- Confirmation
On ce a residual solvent is identifi ed and fou nd to be abov e th e percent daily expo ­
sure limi t, Procedur e B is performed to confirm analyte identity. A G16 capillary
column is used here as a confirmation column, because it yields an alternate selec­
tivity compared to a G43 column. The same standa rd and system suitability pre pa­
rations are used in Procedures A and B. The system suitability requirements differ
here in that th e Class 1 standard solution must have a benzene response grea ter
than 5 and the resolu tion of aceto nitrile and cis-di chloroeth ene must not be less
than 1 in th e Class 2 Mixture A solution, a change from the orig inal version. If th e
ana lyte identified in Procedure A again ma tches the retent ion time and exceeds the
peak respon se of the reference materials (with the same exceptio n to 1,1,1­
trich loroeth ane), the analyst must quant ify th e analyte using Procedure C. Figures
5 th rou gh 7 (pages 5-6) illustr ate the analysis of Class I, Class 2 Mixture A, and
Class 2 Mixture B residu al solvent mixes on a Sta bilwaxv column. Again, the sys­
tem suitability requireme nts were easily met.
Procedure C - Quantification
Once a residual solvent has been ident ified and verified, Procedure C is used to
qu antify the ana lyte by ana lyzing the sample against compo und-specific reference
materials. Indi vidu al standards are prepared by diluti ng the analyte in solution to a
concentra tion of 1/20 of the concentr atio n limit given under concentration limit
Table 1 or 2 of the method. Following the proce dure and instrument conditions in
either Procedure A or B (whichever prov ides the most definitive results), a quan ­
tifiable result is pro duced. For water-insolub le articles, th e same procedure is fol­
lowed, except dimethylformamide or dimeth ylsulfoxide is used as the diluent.
Continued on page 6.
Figure 5 USP residual solvent Class 1 standard solution on a Stabilwa x"
column (G16).
-¥sYSTEM SUITABILITY CRITERIA MET
2,3
SIN
1.1,I ·dichloroethene > 5
2.1,1,I ·trichloroethane > 5
3. carbon tetrachloride > 5
4. benzene > 5
5. 1,2'dichloroethane > 5
t I I I ii I i I I I I I I
2.0 3.0 4.0 min.
GC_PH00951
Column: Stabilwax", 30m, 0.32mm!D, 0.251lm HeadspaceConditions
(cat.# 10624) Instrument: Overbrook Scientific HT200H
Sample: USP Stock Mixture USP< 467> Residual Syringe temp.: IOO' C
Solvents Class I Mix(cat.# 36279) in Sample temp.: 80'C
20mLheadspace vial(cat.# 24685), Sample eqinl. time.: 45 min.
water diluent Injection vol.: l.OmL
Inj.: headspace injection(split ratio 1:5), Injection speed: setting8
2mmsplitless liner IPdeactivated Injection dwell: 5 sec.
(cat.# 20712)
Inj. temp.: 140'C
Carrier gas: helium, constant flow
Flow rate: 2.15mL/min., 35.2cm/ sec.
Oventemp.: 50'C for 20min. to 165'C @ 6' C/min.
(holdfor 20 min.)
Del.: F!D @ 250' C
Product Listing
Capillary Column-Procedure A
Rtx®-1301 (G43) Columns (fused silica)
(Crossbond" 6% cyanopropylphenyl/94% dimethyl polysiloxane)
ill df /J1m) temp. limits length cal #
0.32mm 1.80 -20 to 240' C 30-Meter 16092
0.53mm 3.00 -20 to 240' C 30-Meter 16085
Capillary Column-Procedure B
Stabilwax" Columns (fused silica)
(Crossbond" Carbowax" polyethyleneglycol)
ill df /J1m) temp. limits length cal #
0.32mm 0.25 40 to 250'C 30-Meter 10624
0.53mm 0.25 40 to 250' C 30-Meter 10625
Interested in dual
column analysis?
Review our technical poster on
dual column analysis of residual
solvents.
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