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No.M268

Gas Chromatography Mass Spectrometry

Analysis of Residual Solvents – Class 1, Class 2A, Class 2B – in Pharmaceuticals Using Headspace-GC/MS

LAAN-A-MS-E034

Residual solvents in pharmaceuticals are defined as organic volatile chemicals that are used or produced in the manufacture of drug substances or excipients, or in the preparation of drug products. Residual solvents are classified and managed as Class 1 to Class 3 substances, depending on the risk they pose to human health.According to the USP, "General Chapter <467> Residual Solvents" method, analysis of these residual solvents is to be conducted by the headspace GC-FID method (HS-GC). However in this application, we investigated using headspace-GC/MS (HS-GC/MS) according to Procedure A. Using the HS-GC method, measurement is to be performed as three separate analyses, which are required to achieve chromatographic separation within the three different classes of compounds, Class 1, Class 2A, and Class 2B. However, using HS-GC/MS, complete chromatographic separation is not necessary, so all the compounds can be analyzed in a single run. In addition, compound confirmation and qualitative information of unknown peaks can also be obtained.

n Sample PreparationThe Class 1, Class 2A, and Class 2B aqueous standard solutions were prepared so that the concentrations become the same as standard solution designated in the "USP <467> Residual Solvents" method.

Headspace Sampler : HS-20

Gas Chromatograph Mass Spectrometer : GCMS-QP2010 UltraHSMode : Loop (Volume: 1 mL)Oven Temperature : 80 °CSample Line Temperature : 150 °CTransfer Line Temperature : 150 °CGas Pressure for Vial Pressurization : 100 kPaVial Equilibrating Time :60 minVial Pressurizing Time :2.0 minPressure Equilibrating Time :0.1 minLoad Time :0.1 minLoad Equilibrating Time :0.1 minInjection Time :0.5 minNeedle Flush Time :5.0 minGC

Column : Rxi-624sil MS (30 m × 0.25 I.D.,1.4 µm)

Injection Mode :Split Split Ratio :1:30Control Mode :Constant linear velocity (35 cm/sec)Oven Temperature :40 °C (20 min) → 10 °C/min →

240 °C (20 min)

MSIon Source Temperature : 200 °CInterface Temperature : 250 °CSCAN Range :m/z 29 ~ 200SIM Conditions : Table 1Event Time : SIM 0.2 sec, SCAN 0.3 sec

Compound Name Target Ident 1 Ident 2

Class 1 1,1-Dichloroethene 61 96

1,1,1-Trichloroethane 97 99

Carbon Tetrachloride 117 119

Benzene 78 77 51

1,2-Dichloroethane 62 64

Class 2A Methanol 31 29

Acetonitrile 40 39

Methylene chloride 84 86

trans-1,2-Dichloroethene 96 61

cis-1,2-Dichloroethene 96 61

Tetrahydrofuran 72 42

Cyclohexane 84 56

Methylcyclohexane 98 83

1,4-Dioxane 88 58

Toluene 91 92

Chlorobenzene 112 77

Ethylbenzene 91 106

m,p-Xylene 91 106

o-Xylene 91 106

Class 2B n-Hexane 86 56

Nitromethane 30 46

Chloroform 83 85

1,2-Dimethoxyethane 45 29

Trichloroethene 130 132

Pyridine 79 52

2-Hexanone 58 100

Tetralin 104 132n Analytical Conditions

Table 1 SIM Monitoring Ions

n ResultsFig. 1 shows Total Ion Chromatogram (TIC) for the USP Class 1 compounds. Fig. 2 and 3 are the TICs for Class 2A and 2B compounds, respectively. Peaks that cannot be identified in the TIC and peaks that completely or partially co-elute are shown in the extracted ion chromatogram (EIC). Due to the selectivity of the GC/MS, good separation was obtained by using the SIM acquisition mode. Fig. 4, 5 and 6 show the EIC/SIM chromatograms of the individual components. Good peak shapes we re ob ta ined fo r mos t o f the compounds. In addition, an improved signal-to-noise ratio (S/N) was obtained for CCl4 using the HS-GC/MS method, compared to that obtained by the HS-GC method. Repeatability using the HS-GC/MS SIM mode yielded an RSD of 1.3 to 3.9 % (Tables 2, 3, and 4).

n ConclusionUsing the HS-GC/MS method, simultaneous analysis of USP <467> Class 1, Class 2A, and Class 2B compounds was demonstrated without compromising separation, repeatability, or analysis accuracy.Note: Measurement of residual solvents in pharmaceuticals using HS-

GC/MS has not been adopted as an official method.

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No.M268

Fig. 2 TIC Chromatogram of Class 2A Solvents

Fig. 3 TIC Chromatogram of Class 2B Solvents

Car

bon

tetra

chlo

ride

tran

s

cis

m,p

o

n

Fig. 1 TIC Chromatogram of Class 1 Solvents

ApplicationNews

No.M268

1,1-Dichloroethene 1,1,1-Trichloroethane Carbon tetrachloride Benzene 1,2-Dichloroethane

EIC

SIM

3.5 4.0

2.5

5.0

(×1,000)

61.0096.00

8.5 9.0

2.5

5.0

7.5(×1,000)

99.0097.00

9.0 9.5

1.0

2.0

(×1,000)

119.00117.00

10.0 10.5

2.5

5.0

(×1,000)

51.0077.0078.00

10.0 10.5

0.5

1.0

1.5(×1,000)

64.0062.00

3.5 4.0

2.5

5.0

7.5

(×1,000)

61.0096.00

8.5 9.0

2.5

5.0

7.5

(×1,000)

99.0097.00

9.0 9.5

1.0

2.0

3.0(×1,000)

119.00117.00

10.0 10.5

2.5

5.0

(×1,000)

51.0077.0078.00

10.0 10.5

0.5

1.0

1.5

(×1,000)

64.0062.00

4.0 4.5

2.5

0.0

(×100,000)

86.0084.00

4.5 5.0

0.5

1.0

(×1,000,000)

61.0096.00

7.0 7.5

2.5

5.0

7.5

(×100,000)

61.0096.00

8.5 9.0

1.0

2.0

(×1,000,000)

56.0084.00

14.5 15.0

2.5

5.0

7.5

(×100,000)

83.0098.00

15.5 16.0

1.0

2.0

(×1,000)

58.0088.00

22.0 22.5

1.0

2.0

(×1,000,000)

92.0091.00

27.0 27.5

1.0

2.0

(×1,000,000)

106.0091.00

27.5 28.0

1.0

2.0

(×1,000,000)

106.0091.00

4.0 4.5

2.5

0.0

(×10,000)

39.0040.0041.00

2.0 2.5

1.0

2.0

3.0(×10,000)

29.0031.00

7.5 8.0

0.5

1.0

(×100,000)

42.0072.00

EIC

EIC

SIM

SIM

Methanol

Toluene

Acetonitrile Dichloromethane trans -1,2-dichloroethene cis -1,2-dichloroethene

Tetrahydrofuran Cyclohexane

EIC

m,p-XyleneChlorobenzene Ethylbenzene o-Xylene

SIM

2.0 2.5

1.0

2.0

3.0(×10,000)

29.0031.00

4.0 4.5

0.5

1.0

(×10,000)

39.0040.00

4.0 4.5

2.5

0.0

(×100,000)

86.0084.00

4.5 5.0

0.5

1.0(×1,000,000)

61.0096.00

7.0 7.5

2.5

5.0

(×100,000)

61.0096.00

7.5 8.0

0.5

1.0(×100,000)

42.0072.00

8.5 9.0

1.0

2.0

(×1,000,000)

56.0084.00

14.5 15.0

2.5

5.0

7.5(×100,000)

83.0098.00

15.5 16.0

1.0

2.0

(×1,000)

58.0088.00

22.0 22.5

1.0

2.0

(×1,000,000)

92.0091.00

26.5 27.0

0.5

1.0

(×1,000,000)

77.00112.00

27.0 27.5

1.0

2.0(×1,000,000)

106.0091.00

27.5 28.0

1.0

2.0(×1,000,000)

106.0091.00

28.0 28.5

2.5

0.0

(×1,000,000)

106.0091.00

26.5 27.0

0.5

1.0

(×1,000,000)

77.00112.00

28.0 28.5

2.5

0.0

(×1,000,000)

106.0091.00

1,4-DioxaneMethylcyclohexane

Fig. 4 EIC/SIM Chromatograms of Class 1 Solvents

Fig. 5 EIC/SIM Chromatograms of Class 2A Solvents

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For Research Use Only. Not for use in diagnostic procedures.The content of this publication shall not be reproduced, altered or sold for any commercial purpose without the written approval of Shimadzu. The information contained herein is provided to you "as is" without warranty of any kind including without limitation warranties as to its accuracy or completeness. Shimadzu does not assume any responsibility or liability for any damage, whether direct or indirect, relating to the use of this publication. This publication is based upon the information available to Shimadzu on or before the date of publication, and subject to change without notice.

© Shimadzu Corporation, 2014www.shimadzu.com/an/

M268

First Edition: Oct. 2014

EIC

SIM

n-Hexane

Tetralin2-Hexanone

Nitromethane

Pyridine

5.0 5.5

2.5

5.0

7.5(×10,000)

56.0086.00

7.0 7.5

2.5

5.0

7.5

(×100)

46.0030.00

8.0 8.5

2.5

5.0

(×10,000)

85.0083.00

10.0 10.5

2.5

5.0

(×1,000)

29.0045.00

13.0 13.5

2.5

0.0

(×10,000)

132.00130.00

21.5 22.0

1.0

2.0

3.0(×1,000)

52.0079.00

25.0 25.5

0.5

1.0

1.5(×10,000)

100.0058.00

5.0 5.5

2.5

5.0

7.5

(×10,000)

56.0086.00

7.0 7.5

2.5

5.0

7.5

(×100)

46.0030.00

8.0 8.5

2.5

5.0

(×10,000)

85.0083.00

10.0 10.5

2.5

5.0

7.5(×1,000)

29.0045.00

13.0 13.5

2.5

5.0(×10,000)

132.00130.00

34.5 35.0

2.5

0.0

(×100,000)

132.00104.00

21.5 22.0

1.0

2.0

3.0

(×1,000)

52.0079.00

25.0 25.5

1.0

0.0

(×10,000)

100.0058.00

34.5 35.0

2.5

0.0

(×100,000)

132.00104.00

EIC

SIM

Trichloroethene1,2-DimetoxyethaneChloroform

Fig. 6 EIC/SIM Chromatograms of Class 2B Solvents

Conc. Area RSD (%)

Compound Name (µg/mL) EIC SIM

Class 1 1,1-Dichloroethene 0.018 2.42 2.79

1,1,1-Trichloroethane 0.033 1.86 2.61

Carbon tetrachloride 0.045 1.64 1.62

Benzene 0.064 1.52 2.01

1,2-Dichloroethane 0.085 2.21 2.30

Conc. Area RSD (%)

Compound Name (µg/mL) EIC SIM

Class 2B n-Hexane 0.52 3.46 3.38

Nitromethane 0.82 3.72 2.44

Chloroform 1.97 2.48 2.67

1,2-Dimethoxyethane 0.42 2.62 2.74

Trichloroethene 0.42 1.23 1.56

Pyridine 1.67 2.94 3.29

2-Hexanone 0.83 0.83 1.34

Tetralin 0.65 1.87 1.77

Conc. Area RSD (%)

Compound Name (µg/mL) EIC SIM

Class 2A Methanol 3.03 4.26 3.83

Acetonitrile 2.85 2.74 3.29

Methylene Chloride 27.0 2.24 2.78

trans-1,2-Dichloroethene 14.6 1.91 2.60

cis-1,2-Dichloroethene 5.05 1.93 2.49

Tetrahydrofuran 3.12 1.87 2.12

Cyclohexane 24.1 1.67 2.27

Methylcyclohexane 8.72 1.33 1.69

1,4-Dioxane 6.15 3.13 2.54

Toluene 7.00 1.17 1.56

Chlorobenzene 2.92 1.30 1.28

Ethylbenzene 1.47 1.32 1.41

m,p-Xylene 2.48 1.07 1.41

o-Xylene 10.3 1.23 1.66

Table 2 Repeatability of Peak Area of Class 1 Solvents (n = 6)

Table 4 Repeatability of Peak Area of Class 2B Solvents (n = 6)

Table 3 Repeatability of Peak Area of Class 2A Solvents (n = 6)