Application Note
Pharma & Biopharma

Quantification of Nine Nitrosamine
Impurities in Sartan Drugs Using an
Agilent GC-TQ

Authors
Soma Dasgupta, Vivek Dhyani,
and Melissa Churley
Agilent Technologies, Inc.

Abstract
In this application note, a method for the analysis of nine nitrosamine impurities
was developed using the Agilent 8890 GC equipped with an Agilent 7693A
automatic liquid sampler coupled to an Agilent 7010B triple quadrupole GC/MS/MS.
Three different columns were evaluated using two GC programs (12 minutes and
20 minutes) for the nine impurities. Excellent linearities with R2 >0.997 were obtainedin this study. Long-term repeatability studies done by consecutive injections of
150 spiked samples at 30 ng/g of sample yielded <8% RSD, indicating long-term
precision of the method. Sample recoveries were calculated by fortifying the
drug substance and a homogenized drug product at 30 ng/g, which was foundto be satisfactory (within the range of 80 to 120% for all target analytes). A USP
signal-to-noise ratio (S/N) of 10 was used as a basis for LOQ determination in themethod. In the present study, S/N values for samples spiked at concentrations ofless than 0.002 ppm with respect to sample was evaluated, suggesting that the
instrument meets the sensitivity requirements easily, and further lower LOQs could
be achieved.

Introduction
Nitrosamine impurities have beenreported in several drugs and drug
substances. Several drugs havebeen recalled due to the presenceof N-nitrosodimethylamine (NDMA).
As a result, regulatory agencies havereleased methods and guidance
documents covering a greater numberof nitrosamine impurities. All medicines
containing chemically synthesized
active pharmaceutical ingredients(APIs) are now required to review the
product for the possible presence of
N-nitrosamines. In earlier application
notes, a method for the identificationof five nitrosamines was validated insartan and metformin drugs. The earlier
GC methods were developed using a
VF-WAXms column within a run time of
12 minutes. Other potential interferencessuch as dimethylformamide (DMF) may
also be present in some drugs. This has
previously been reported and can leadto false quantification results for NDMA.
This application note expands the scopeof the method from five impurities to thenine impurities:– N-nitrosodimethylamine (NDMA)– N-nitrosomethylethylamine (NMEA)– N-nitrosodiethylamine (NDEA)– N-nitroso-ethylisopropylamine(NEIPA)– N-nitrosodiisopropylamine (NDIPA)– N-nitrosodipropylamine (NDPA)– N-nitrosodi-n-butylamine (NDBA)– N-nitrosopiperidine (NPIP)– N-nitrosopyrrolidine (NPYR)

2This application note also explores theeffect of varying DMF concentrations
on NDMA peak shapes, and different
GC columns on sensitivity of analysis.
Two GC programs (resulting in 12 and20 minute run times) are also comparedwith respect to precision and sensitivity.
As these methods are used for routine
analysis of drug substances, long-term
precision is also studied.

Experimental
Sample preparation
The APIs and drug products tested
for this analysis included valsartan,
olmesartan, losartan, irbesartan, andtelmisartan. Sample preparation was
similar to the process described inapplication note 5994-1821EN. For
drug substance, a portion of 500 mg
of drug substance was weighed
accurately into a disposable 15 mL glass
centrifuge tube, and 5 mL of internal
standard solution (~50 ng/mL NDMA-d6
in dichloromethane) was added via
volumetric pipette. These samples werevortexed for 1 minute, then placed in
the centrifuge and spun at 4,000 rpm
for 5 minutes. The undissolved drug
substance settled at the bottom. Usinga disposable pipette, approximately
2 mL of the dichloromethane layer was
filtered through a 0.45 µm nylon filter andtransferred to a GC vial for analysis. For
the finished drug product, approximately
10 tablets of each drug were separately
crushed and homogenized. Fromthe homogenized mixture, a portion
equivalent to 500 mg of drug substancewas weighed and extraction was carriedout in the same manner as described for
drug substance.

Standard preparation
The standard stock was diluted
appropriately to obtain a calibration
solution in the range of 0.06 to
500 ng/mL, each prepared indichloromethane containing NDMA-d6 asinternal standard.

Instrumentation
Analysis was performed using theAgilent 8890 GC equipped with an
Agilent 7693A automatic liquid sampler
coupled to an Agilent 7010B triple
quadrupole GC/MS/MS. Three different
columns were evaluated using two GC
programs (12 and 20 minutes) for thenine impurities.
The columns evaluated were:– Agilent J&W VF-WAXms GC
capillary column of dimensions
30 m × 0.25 mm × 0.25 µm(part number CP9205)– Agilent J&W DB-Select 624 UI GC
capillary column of dimensions
30 m × 0.25 mm × 1.4 µm(part number 122-0334UI)– Agilent J&W DB-1701 GC
capillary column of dimensions
30 m × 0.25 mm × 1 µm
(part number 122‑0733)
Tables 1 and 2 display the GC andMS parameters.

MS acquisition method
Using the Multiple Reaction Monitoring(MRM) optimizer tool, the MRMs for allnine impurities were developed and used
for data acquisition.

Table 1. GC parameters.

Table 2. MS parameters.

Parameter

Value

Parameter

MMI Injection Mode

Pulsed splitless: 12.285 psi until 0.5 min

Inlet Temperature

250 °C
Ultra Inert, splitless, single taper, glass wool (p/n 5190-2293)

Inlet Liner

Method 1 (12 min)Method 2 (20 min)

40 °C (0.5 min)
20 °C/min to 200 °C (0 min)
60 °C/min to 250 °C (3 min)

40 °C (0.5 min)
10 °C/min to 145 °C (1 min)
20 °C/min to 190 °C (5 min)
60 °C/min to 250 °C (0 min)Total Run Time12.33 min20.25 minMS Transfer Line Temperature

250 °CInjection Volume

2 µL

Carrier Gas

Helium, 1 mL/min

Oven Temperature Program

Value

Mode

Electron impact, 70 eV

Source Temperature

250 °C

Quadrupole Temperature

Q1 and Q2 = 150 °C

MRM Mode Conditions
MS1 and MS2 Resolution

All compounds Unit

Collision Gas Flow

Nitrogen at 1.5 mL/min

Quench Gas Flow

Helium at 4 mL/min

Table 3. Quantitative/qualitative transitions (dMRM-based).
Retention Time (RT in min)Agilent VF-WAXms

Agilent DB-Select 624 UIAgilent DB-1701

Compound12 min20 min

12 min20 min

12 min20 minMRM
Transition

CE

NDMA-D6

5.387

7.757

5.799

8.122

5.861

8.290

80 & 50

574 & 44.1

6

74 & 42.1

24

43.1 & 42.1

10

NDMA

NMEA

NDEA

NEIPA

NDIPA

NDPA

NPYR

NPIP

NDBA

5.392

5.758

5.974

6.221

6.406

6.930

8.518

8.332

8.072

7.777

8.413

8.795

9.250

9.589

10.58013.66813.30412.951

5.821

6.688

7.376

7.978

8.493

8.927

9.130

9.389

10.155

8.157

9.792

11.10912.38613.381

14.19014.53115.06617.292

5.884

6.676

7.288

7.822

8.271

8.730

9.165

9.329

9.902

8.313

9.819

10.99512.13713.05513.89914.66114.98516.62887.9 & 71

4

87.9 & 42.1

24

43.1 & 42.1

10

101.9 & 85.1

4

101.9 & 56

20

101.9 & 44.1

14115.9 & 99

6

115.9 & 44

16

71 & 566

130 & 886130 & 7116

130 & 42.1

12

130 & 113.1

2

101 & 702

70 & 43.1

6

99.9 & 70

8

99.9 & 55

8

99.9 & 43.1

12113.9 & 97.1

8

113.9 & 84.1

8

113.9 & 55

26

113.9 & 42.1

24

158 & 141.1

4

158 & 99.1

10

116 & 99.1

4

84 & 5622

3

Results and discussion

Two different GC programs were
evaluated for each column. Figures 1
and 2 contain chromatograms
obtained using method 1 (12 minuterun time) and method 2 (20 minute runtime), respectively. The compounds
were separated sufficiently, and thetarget peaks (Figures 1 and 2) werewell‑resolved.

The MRMs for this method weredeveloped using the Agilent MassHunter
Optimizer for GC/TQ. AutomatedMRM development was carried out toobtain the optimized MRMs of all nine
impurities. The process for automatedMRM development is described in
5994-2086EN. The optimized MRMs
were saved directly as a dMRM method
and used for acquisition of calibration
standards and samples.

A ×105Counts

8 1

The elution profiles and retention
time (RT) in DB-Select 624 UI and
DB-1701 were similar. The elution
order in VF‑WAXms was different
from the other two columns with

Agilent VF-WAXms, 30 m × 0.25 mm, 0.25 µm (p/n CP9205)
1

6

9

4

2

7

2
0

B ×105
5Agilent J&W DB-Select 624 UI, 30 m × 0.25 mm, 1.4 µm (p/n 122-0334UI)
1
1

4
Counts

12.33 minute GC program
40 °C (0.5 min)
20 °C/min to 200 °C (0 min)
60 °C/min to 250 °C (3 min)

1. NDMA
2. NMEA
3. NDEA
4. NEIPA
5. NDIPA
6. NDPA
7. NPYR
8. NPIP
9. NDBA

1

8

6

5

3

4

NDBA (12.951 minutes) eluting before
NPIP (13.304 minutes) and NPYR
(13.668 minutes). With the same GC
program, elution of all the compounds
was faster in VF-WAXms as comparedto the other two columns. Comparisonof peak shapes across the columns
indicated DB-1701 with overall
symmetric peak shapes. The USP tailingfactor ranged from 0.9 to 1.2 in DB-1701
as compared to 0.8 to 1.3 and 1.2 to
1.6 in VF-WAXms and DB-Select 624 UI,
respectively.

8
4

2

3

7

6

5

3

2

1
9

1
0

C ×105Counts8
6

Agilent J&W DB-1701, 30 m × 0.25 mm, 1 µm (p/n 122-0733)
1
1
2

1
3

4

8

4
7

6

5

9

2
0
5.4

5.6

5.8

6.0

6.2

6.4

6.6

6.8

7.0

7.2

7.4 7.6 7.8 8.0 8.2
Acquisition time (min)

8.4

8.6

8.8

9.0

9.2

9.4

9.6

9.8

10.0 10.2

Figure 1. MRM chromatogram of nine impurities N-nitrosodimethylamine (NDMA) (1), N-nitrosomethylethylamine (NMEA) (2), N-nitrosodiethylamine (NDEA) (3),N-nitroso-ethylisopropylamine (NEIPA) (4), N-nitrosodiisopropylamine (NDIPA) (5), N-nitrosodipropylamine (NDPA) (6), N-nitrosopyrrolidine (NPYR) (7),N-nitrosopiperidine (NPIP) (8), N-nitrosodi-n-butylamine (NDBA) (9) in three columns: Agilent VF-WAXms (A), Agilent DB-Select 624 UI (B) and Agilent DB‑1701 (C)for Method 1 (12 minute run time).

4

Counts

A

CountsB

CountsC

Agilent VF-WAXms, 30 m × 0.25 mm, 0.25 µm (p/n CP9205)
×105
1
6 1
5
4
4
2
6
3
5
3
2
1
0

7

×105 Agilent J&W DB-Select 624 UI, 30 m × 0.25 mm, 1.4 µm (p/n 122-0334UI)
3.0
1 1
2.5
2
2.0
3
1.5
1.0
0.5
0
×105 Agilent J&W DB-1701, 30 m × 0.25 mm, 1 µm (p/n 122-0733)
6
1 1
5
2
4
3
3

20.25 minute GC program
40 °C (0.5 min)
10 °C/min to 145 °C (1 min)
20 °C/min to 190 °C (5 min)
60 °C/min to 250 °C (0 min)

1. NDMA
2. NMEA
3. NDEA
4. NEIPA
5. NDIPA
6. NDPA
7. NPYR
8. NPIP
9. NDBA

1

8

9

8
4

6

5

1
9

7

1
4

6

5

7

8
9

2
1
0
7.5

8.0

8.5

9.0

9.5

10.0

10.5

11.0

11.5

12.0

12.5

13.0

13.5

14.0

14.5

15.0

15.5

16.0

16.5

17.0

Acquisition time (min)Figure 2. MRM chromatogram of nine impurities N-nitrosodimethylamine (NDMA) (1), N-nitrosomethylethylamine (NMEA) (2), N-nitrosodiethylamine (NDEA) (3),N-nitroso-ethylisopropylamine (NEIPA) (4), N-nitrosodiisopropylamine (NDIPA) (5), N-nitrosodipropylamine (NDPA)(6), N-nitrosopyrrolidine (NPYR) (7),N-nitrosopiperidine (NPIP) (8), N-nitrosodi-n-butylamine (NDBA) (9) in three columns: Agilent VF-WAXms (A), Agilent DB-Select 624 UI (B) and Agilent DB-1701 (B)for Method 2 (20 minute run time).

In the VF-WAXms column, peaks of
NDMA and DMF elute very close to eachother (Figure 3). The DMF concentration
was increased from 5 to 100 mg/L

and the effect on the NDMA peak
was noted. At a DMF concentration
greater than 100 mg/L, peak tailing of
NDMA was noted. The change in peak

12.33 minute GC program

20.25 minute GC program

100 mg/L DMF

Counts (%)

Counts (%)

10 mg/L DMF

×10-1
8
6
4
2
0
2.5
2.0
1.5
1.0
0.5
0
5.4

5.5
5.6
Acquisition time (min)

5.7

5.8

Counts (%)×10-1
Counts (%)

8
6
4
2

×10-1
4
3
2
1
0

Counts (%)

5 mg/L DMF

Counts (%)

×10-1

5.3

shape of NDMA may lead to an error in
identification and quantification of NDMA
in the presence of DMF.

3
2
1
0
1.0
0.5
0
7.5

7.6

7.7
7.8
7.9
Acquisition time (min)

8.0

8.1

Figure 3. N-nitrosodimethylamine (NDMA) (0.2 ng/mL) and dimethylformamide (DMF) elute very close in both GC programs when analyzed with an
Agilent VF‑WAXms column. NDMA peaks show tailing at higher concentrations of DMF.

5

Even at higher DMF concentrations,peak areas of NDMA were comparable
to those obtained at lower DMF content(Figure 4). When compared acrossthe DMF concentration range of 2 to
100 mg/L, the variation in peaks area of
NDMA (present at 0.2 ng/mL) was within
9.5%. This ensured that despite thepresence of DMF in samples, NDMA canbe chromatographically separated andquantified, even when present at very
low concentrations.
Response in terms of peak area
indicated slightly higher response
for both slow and fast GC programsin the DB-1701 column. Further
studies on repeatability, calibration,and sample analysis were therefore
carried out on the DB-1701 column.
Repeatability studies were performedby 150 successive injections of a spiked
sample at 30 ppb with respect to drug
substance. The peak area trend is shownin Figure 5. RSDs calculated with respect
to absolute areas were 3.07, 3.96, 4.66,
5.26, 5.94, 4.59, 7.69, 5.66, and 4.72%
respectively for NDMA, NMEA, NDEA,NEIPA, NDIPA, NDPA, NDBA, NPIP,
and NPYR, while RSDs of calculated
concentration (after internal standard

6

Counts (%)

1.0
0.5
0

Counts (%)

×10-1
1.0
0.5
0

×10-1
Counts (%)

DMF is a class 2 solvent with aconcentration limit of 880 ppm.
Considering the possibility of presenceof DMF at higher concentrations, DMF
was varied up to 100 mg/L or 1,000 ppm
with respect to drug substance, while
maintaining a trace concentration of
NDMA at 0.2 ng/mL or 0.002 ppm withrespect to drug substance.

×10-1

1.0
0.5
0

×10-1
Counts (%)

Sufficient separation was observed
between DMF and the target analytes
when DB-Select 624 UI and DB-1701
were used for chromatographic
separation. Peaks shapes of NDMA were
not affected with varying concentrationsof DMF evaluated from 2 to 100 mg/L
(Figure 4).

1.0
0.5
0

5.7

5.8

5.9

6.0

6.1

6.2

6.3

6.4

Acquisition time (min)Figure 4. In an Agilent DB-Select 624 UI column, N-nitrosodimethylamine (NDMA) peaks were well
separated from dimethylformamide (DMF) (concentration ranging from 2 to 100 ppm).

×104
2.1
2.0
1.9
1.8
1.7
1.6
1.5
1.4
1.3
1.2
1.1
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
-0.1
-0.2
-0.3
-0.4
-0.5
-0.6

Metrics plot
Area - N-Nitrosodimethylamine (NDMA) Results
Area - Ethanamine, N-methyl-N-nitroso-(NMEA) Results
Area - Ethanamine, N-ethyl-N-nitroso-(NDEA) Results
Area - 2-Propanamine, N-ethyl-N-nitroso-(NEIPA) Results
Area - 2-Propanamine, N-(1-methylethyl)-N-nitroso-(NDIPA) Results
Area - 1-Propanamine, N-nitroso-N-propyl-(NDPA) Results
Area - 1-Butanamine, N-butyl-N-nitroso-(NDBA) Results
Area - Piperidine, 1-nitroso-(NPIP) Results
Area - Pyrrolidine, 1-nitroso-(NPYR) Results

2

10

18

26

34

42

50

58

66

74

82

90

98 106 114 122 130 138 146 154 162 170

Figure 5. This figure displays the peak area trend, as output by the metric plot feature of
Agilent Quantitative Analysis software for nine nitrosamine impurities at 30 ppb with respect todrug substance.

2.5
2.0
1.5
1.0
0.5
0
0

Relative response

2.5

100 150 200 250 300
Relative concentration

2-Propanamine, N-ethyl-N-nitroso-(NEIPA)
y = 0.770741x + 0.038418
R2 = 0.99776411

×102

2.0
1.5
1.0
0.5
0
50

100 150 200 250 300
Relative concentration

×102 1-Butanamine, N-butyl-N-nitroso-(NDBA)
y = 0.472342x – 0.002811
R2 = 0.99764945
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
0

50

100 150 200 250 300
Relative concentration

×102
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0

1.0
0.8
0.6
0.4
0.2

50

100 150 200 250 300
Relative concentration

050

100 150 200 250 300
Relative concentration

1-Propanamine, N-nitroso-N-propyl-(NDPA)
2-Propanamine, N-(1-methylethyl)-N-nitroso-(NDIPA)×102
y = 0.520436x + 0.032529
y = 0.609063x + 0.043640
2.0 R2 = 0.99834443
R2 = 0.99856353
1.5
1.0
0.5
0
0

Relative response

Relative response

0

1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0

Ethanamine, N-ethyl-N-nitroso-(NDEA)
y = 0.379321x + 0.028011
1.2 R2 = 0.99761262

×102

0
0

Relative response

×102

50

1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0

Ethanamine, N-methyl-N-nitroso-(NMEA)
y = 0.548904x + 0.071531
R2 = 0.99712608

Relative response

3.0

×102

and DB‑Select 624 UI indicated similar
results. Any of the three columns canbe used for the analysis. However, inthe presence of DMF, identification andquantification of NDMA was affected inthe VF-WAXms column.

Relative response

N-Nitrosodimethylamine (NDMA)
y = 1.120025x + 0.163329
R2 = 0.99744066
Relative response

Relative response

×102
3.5

Correlation coefficients were >0.997 for
all compounds. Linearity was obtained
from 0.06 to 500 ng/mL for NDEA,NEIPA, and NDIPA, 0.1 to 500 ng/mL
for NDMA, NDPA, NDBA, and NPIP, and
0.2 to 500 ng/mL for NMEA and NPYR.
A separate study done with VF-WAXms

50

100 150 200 250 300
Relative concentration

Piperidine, 1-nitroso-(NPIP)
y = 0.470472x + 0.029072
R2 = 0.99807332

0

0

50

100 150 200 250 300
Relative concentration

50

100 150 200 250 300
Relative concentration

Pyrrolidine, 1-nitroso-(NPYR)
y = 0.287016x + 0.031526
2
0.9 R = 0.99746197
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0

×102

Relative response

correction) were 1.15, 1.79, 2.71,
3.48, 4.39, 2.49, 5.79, 4.01, and 2.97%,
respectively. This indicated long-term
stability of response and applicability ofmethod for routine analysis. Calibration
curves were plotted for all nine impurities
prepared in dichloromethane (Figure 6).

050

100 150 200 250 300
Relative concentration

Figure 6. Internal standard-based calibration curve of nine nitrosamine impurities in the range of 0.06 to 500 ng/mL (14-level calibration curve for NDEA, NEIPA,
and NDIPA), 0.1 to 500 ng/mL (13-level calibration curve for NDMA, NDPA, NDBA, and NPIP), and 0.2 to 500 ng/mL (12-level calibration curve for NMEA and
NPYR). Results were obtained using an Agilent DB‑1701 column.

7

×102
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0

0.4
0.2
0

1.1
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0

14.0

1.4

0
11.0

11.1

1.2

Counts1.0

MRM (99.9 & 55.0) NPYR

×102
3.0

RT = 14.658 min
S/N = 30.97
Calc. Conc.=
0.2533 ng/mL

2.5

12.2

12.3

MRM (113.9 & 84.1) NPIP
RT = 14.979 min
S/N = 25.55
Calc. Conc.=
0.1000 ng/mL

2.0
1.5
1.0
0.5
0

14.6

14.7

14.8

MRM (130.0 & 88.0) NDIPA
RT = 13.045 min
S/N = 36.95
Calc. Conc.=
0.0583 ng/mL

0.8
0.6

0
16.8

12.1

Acquisition time (min)0.2

Acquisition time (min)

12.0

14.8

14.9

15.0

15.1

Acquisition time (min)×102Counts

×102

16.7

0.8

0.2

0.4

16.6

1.0

Acquisition time (min)MRM (116.0 & 99.1) NDBA
RT=16.620 min
S/N=31.94
Calc. Conc.=
0.0974 ng/mL

16.5

1.2

RT = 12.130 min
S/N = 35.62
Calc. Conc.=
0.0506 ng/mL

0.4

14.5

Acquisition time (min)Counts1.6CountsCountsCounts

0.6

×102
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0

MRM (115.9 & 99.0) NEIPA

0.6

10.9

×103

0.8

13.9

– NMEA and NPYR (0.002 ppm)

Acquisition time (min)MRM (130.0 & 113.1) NDPA
RT = 13.901 min
S/N = 30.53
Calc. Conc.=
0.1000 ng/mL

13.8– NDMA, NDPA, NDBA, and NPIP
(0.001 ppm)

×102

RT = 10.993 min
S/N = 36.14
Calc. Conc.=
0.0500 ng/mL

Acquisition time (min)1.0– NDEA, NEIPA, and NDIPA(0.0006 ppm)

MRM (101.9 & 85.1) NDEAMRM (74.0 & 44.1) NDMA
RT = 8.316 min
S/N = 23.53
Calc. Conc.=
0.1036 ng/mL

8.15 8.20 8.25 8.30 8.35 8.40 8.45 8.50

×102
1.2

nine impurities using the Agilent DB-1701
column with 20 minute run time is shownin Figure 7. The compounds are present
in following concentrations:

Counts

×103
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0

A USP S/N value of 10 was used asa basis for LOQ determination in themethod. In the present study, S/N values
for samples spiked at 3 ppb with respect
to drug substance level were foundto be greater than 10, suggesting thatthe instrument meets the sensitivity
requirements easily, and further lower
LOQs could be achieved, enabling
trace‑level detections. The S/N of theCountsCountsSamples of drug substance and drug
product were analyzed using themethod described. Sample recoveries
were calculated by fortifying the drug
substance and drug products ofvalsartan, irbesartan, losartan, andtelmisartan with a homogenized drug
product at 0.03 and 0.003 ppm and were
found to be satisfactory within the rangeof 80 to 120% when analyzed using threedifferent columns at both (0.03 and0.003 ppm) levels.

2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0

MRM (87.9 & 71.0) NMEA
RT = 9.824 min
S/N = 37.34
Calc. Conc.=
0.1531 ng/mL

12.9 12.95 13.0 13.05 13.1 13.15 13.2

9.65 9.7 9.75 9.8 9.85 9.9 9.95 10.0

Acquisition time (min)Acquisition time (min)Figure 7. The signal-to-noise ratio of nine nitrosamine impurities was greater than 10 for all nine impurities at the following concentrations: NDEA, NEIPA, and
NDIPA (0.0006 ppm); NDMA, NDPA, NDBA, and NPIP (0.001 ppm); NMEA, and NPYR (0.002 ppm) using an Agilent DB-1701 column with a 20-minute run time.

8Conclusion

References

The Agilent 8890 and Agilent 7010B
GC/MS/MS system demonstrated
excellent performance for determinationof nine nitrosamine drug impurities insartan drug products and substances.
The design of the 7010B triple
quadrupole GC/MS/MS, which includes
the High Efficiency Source (HES),
enables lower detection limits fortrace‑level impurities when combinedwith the inert sample path provided
by the 8890 GC. These features
enabled reliable quantification of allnine impurities up to 3 ppb. The S/N ofrecovery samples spiked at 3 ppb withrespect to drug substance indicated thatfurther lower levels could be achieved.
The lowest calibration level achieved forthe nitrosamine impurities ranged from
0.0006 to 0.001 ppm with respect todrug substance. All three columns could
be used for analysis, as satisfactorylinearity, recovery, and repeatability
could be achieved for all nine impurities.
The Agilent DB-1701 was found to
be more suitable for the analysis due
to separation from DMF and lesser
peak tailing.

1. https://www.ema.europa.eu/
en/human-regulatory/postauthorisation/referral-procedures/
nitrosamine-impurities
2. https://www.ema.europa.eu/en/
news/ema-update-metformindiabetes-medicines
3. https://www.fda.gov/drugs/drugsafety-and-availability/fda-updatesand-press-announcements-ndmametformin
4. https://www.edqm.eu/en/ad-hocprojects-omcl-network#Methods%20
for%20determination%20of%20
nitrosamines%20in%20metformin
5. Analysis of Five Nitrosamine
Impurities in Drug Products andDrug Substances Using Agilent
GC/MS/MS Instrumentation. Agilent
Technologies application note,publication number 5994-1821EN,
2020.
6. Quantification of Nitrosamine
Impurities in Metformin Using Agilent
GC/MS/MS Instrumentation. Agilent
Technologies application note,publication number 5994-2419EN,
2020.
7. Automated MRM Method
Development for US EPA Method
8270 with the Agilent MassHunter
Optimizer for GC/TQ. Agilent
Technologies application note,publication number 5994-2086EN,
2020.

www.agilent.com
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This information is subject to change without notice.
© Agilent Technologies, Inc. 2022
Printed in the USA, March 4, 2022
5994-4618EN