CN109696499A - A kind of nitrosamine Sensitive Determination method in the water based on high resolution mass spec - Google Patents

Abstract

The invention discloses a kind of nitrosamine Sensitive Determination methods in water based on high resolution mass spec, it is characterized by comprising following steps: water sample is after sample pre-treatments, using chromatography post separation, high resolution mass spectrum full scan mode detection, inner mark method ration, the sample pre-treatments include that solid phase extraction concentration and nitrogen blow quantitative concentration.The method of the present invention is 0.05~0.5ng/L for the detection limit (LOD) of different material, quantitative limit (LOQ) is 0.1~1.0ng/L, horizontal far below the limitation of current countries in the world, the range of linearity is 0.2~500 μ g/L, related coefficient (R²) it is 0.9943~0.9997.

Description

A kind of nitrosamine Sensitive Determination method in the water based on high resolution mass spec

Technical field

The present invention relates to the measuring methods of chemical substance, more particularly to nitrous in a kind of water based on high resolution mass spec Amine Sensitive Determination method.

Background technique

Nitrosamine is a kind of pollutant with-N-N=O structure, so far it has been found that more than 300 kinds of nitrosamine in about Have 90% there is carcinogenesis.It is detected in beer, bacon product, cosmetics, tobacco and latex product in recent years. Nitrosamine is known as " PM 2.5 in water " by media, has found nitrosamine in river water, underground water, sewage and drinking water In the presence of studies have shown that including chlorine dioxide, the disinfecting process combination ultraviolet light etc. including ozone and chlorine may cause nitrosamine Content increases.The safety problem of nitrosamine is gradually taken seriously in drinking water, and International Agency for Research on Cancer (IARC) is by N- nitroso Dimethylamine (NDMA) and N-Nitrosodiethylamine (NDEA) are classified as 2A class carcinogenic substance, by N- nitroso di-n-propylamine (NDPA), N- Nitroso Methylethyl amine (NMEA), N-nitrosomorpholine (NMOR), N- nitroso pyrroles (NPYR), N-nitroso-piperidine (NPIP) and N- nitroso dibutyl amine (NDBA) is classified as 2B class carcinogenic substance.Environmental Protection Agency (EPA) regulation NDEA, NDMA, (carcinogenic risk reaches 10 to maximum permissible concentration in NDBA and NPYR water body^-5When) it is respectively 2,7,60 and 200ng/L；Add benefit The state Fu Niya provides that the limitation of NDMA, NDEA and NDPA in drinking water are 10ng/L；The maximum of Germany regulation NDMA and NMOR is residual Staying limitation is 10ng/L；Provide that NDMA limit value is 40ng/L in Canadian national standard.Also the drinking water Central Asia is urgently put into effect in China The limit standard of nitramine.

Since the limitation and content of nitrosamine in water are extremely low, the pre-treatment step of preenrichment concentration is essential.? In the pretreatment technologies such as the liquid-liquid extraction (LLE) of report, Solid Phase Extraction (SPE), solid phase microextraction (SPME), SPE can be to substantially Ponding sample is extracted, and has the characteristics that favorable reproducibility, cycles of concentration are high, the extraction of nitrosamine suitable for various types water body It takes, can also select suitable filler according to water sample type, be the main means of nitrosamine extraction in water.Nitrosamine in water at present Detection method have liquid chromatogram (HPLC), liquid chromatography-mass spectrography (HPLC-MS), gas-chromatography (GC) and gas-chromatography-matter (GC-MS) etc. is composed, if China rower HJ 809-2016 is using 4 kinds of nitrosamine in Water By Gas Chromatography.Research is found The selectivity detected using simple chromatography or Low Resolution Mass Spectra is poor, easily Chong Die with interfering compound, generates false positive；Wherein Electron impact ionization source (source EI) GC-MS is also easy to produce indiscriminate fragment ion, brings difficulty to examination chaff interferent and object.

Summary of the invention

The technical problem to be solved in the present invention is to provide the highly sensitive surveys of nitrosamine in a kind of water based on high resolution mass spec Determine method.

SPE combination gas-chromatography-electrostatic field orbit trap high resolution mass spectrum is established 16 kinds of trace Asias in drinking water by the present invention The detection method of nitramine.Chromatographic mass spectrometry condition is optimized first to improve the sensitivity of instrument detection, it is orthogonal by designing Next test is evaluated the quantitative limit of method, linear, the rate of recovery, precision etc., finally to optimize SPE extraction conditions It is measured applied to actual water sample.

A kind of nitrosamine Sensitive Determination method in the water based on high resolution mass spec, includes the following steps: that water sample is passing through After crossing sample pre-treatments, using chromatography post separation, high resolution mass spectrum full scan mode detection, inner mark method ration, before the sample Processing includes that solid phase extraction concentration and nitrogen blow quantitative concentration.

Nitrosamine Sensitive Determination method in water of the present invention based on high resolution mass spec, wherein the sample Pretreatment process, which specifically comprises the following steps: to be added in 1L water sample to mix after the 0.5mg/L inner mark solution of 50 μ L, to be stood, Chromabond HR-P solid-phase extraction column successively uses 5mL methanol to activate, 5mL water balance, then by water sample with 3mL/min or so Flow velocity crosses column, after completion of the sample, drains 1min, is eluted with 10mL ethyl acetate, collects eluent, be added anhydrous sodium sulfate into Row dehydration, supernatant liquid nitrogen is finally blown quantitatively be concentrated into 0.5mL, is measured for upper machine.

Nitrosamine Sensitive Determination method in water of the present invention based on high resolution mass spec, wherein the nitrous Amine is N- nitrosodimethylamine, N- nitroso Methylethyl amine, N-Nitrosodiethylamine, N- nitrosodiisopropylamine, N- nitrous Base di-n-propylamine, N- nitroso-methylphenylamine, N- nitroso di-iso-butylmanice, N- nitroso-ethylaniline, N- nitroso pyrrole Cough up alkane, N-nitrosomorpholine, N-nitroso-piperidine, N- nitroso dibutyl amine, N nitrosodiphenyl amine, two hexamethylene of N- nitroso Base amine, N- nitroso-N.N (3.5.5- trimethyl) amine and N- nitroso dibenzyl amine.

Nitrosamine Sensitive Determination method in water of the present invention based on high resolution mass spec, wherein chromatographic condition It is as follows: DB-35MS chromatographic column, 30m × 0.25mm × 0.25 μm；Carrier gas high-purity helium, 99.999%；1 μ L of sampling volume；Arteries and veins Rush Splitless injecting samples, pulse 200kPa, burst length 1min；Flow rate of carrier gas 2.0mL/min；250 DEG C of injector temperature, 250 DEG C of transmission line temperature；Temperature programming: initial temperature is 40 DEG C, rises to 270 DEG C after holding 1min with 15 DEG C/min rate, protects Hold 5min.

Nitrosamine Sensitive Determination method in water of the present invention based on high resolution mass spec, wherein Mass Spectrometry Conditions It is as follows: resolution ratio 60000FWHM, 200m/z；EI ionization source, ion source temperature 280Solvent delay 3min；Full scan mould Formula, 40~300m/z of scanning range.

Nitrosamine Sensitive Determination method in water of the present invention based on high resolution mass spec, in which:

Target is qualitative in 16 kinds of nitrosamine and 2 kinds and quota ion is shown in Table 1:

1 16 kinds of nitrosamine substances of table and the retention time of two kinds of internal standard compounds, qualitatively and quantitatively ion

^aIt indicates with NDMA-d₆It is quantified for internal standard；^bIt indicates with NDPA-d₁₄It is quantified for internal standard；NA^cIndicate data It does not provide.

The present invention is based on nitrosamine Sensitive Determination method differences from prior art in the water of high resolution mass spec to exist In: the present invention is mainly to use gas chromatograph-high resolved rate mass spectrum (resolution ratio reaches as high as 120,000) measurement underwater trace 16 kinds of nitrosamine, so as to obtain the accurate mass number of each substance, being accurate to after decimal point the 5th, (conventional mass spectrum is Low resolution can only measure one decimal place).Advantage 1 is high sensitivity, and the comparison of Cong Wenzhong table 6 is it can be seen that detect limit Lower than ng/L rank, it is better than existing domestic and international technology.Advantage 2 is more accurate to substance detection (for example to extract 102.02931 Peak after ion is certainly cleaner than the peak after 102 ions of extraction, namely selectivity is higher), quality error≤1.839ppm, Therefore there is very high selectivity and accuracy to target substance, substantially reduces the detection of conventional low resolution mass spectrometry false positive As a result.Highly sensitive high accuracy this exactly use advantage specific to high resolution mass spec.

Water sample is tested after solid phase extraction concentration, nitrogen blow quantitative concentration, DB-35MS chromatography post separation, high resolution mass spectrum Full scan mode detection, inner mark method ration.To the chromatographic separation condition of method, mass ions source temperature, chromatography flow rate of carrier gas, Input mode and pulse etc. optimize, and obtaining optimal conditions is 280 DEG C of ion source temperature, flow rate of carrier gas 2.0mL/ Min, pulse do not shunt and pulse is 200kPa.It tests to obtain optimal Solid Phase Extraction by four factors, three horizontal quadrature Condition is Chromabond HR-P extraction column, the elution of 10mL ethyl acetate.The result shows that detection of the method for different material Limiting (LOD) is 0.05~0.5ng/L, and quantitative limit (LOQ) is 0.1~1.0ng/L, far below the limitation water of current countries in the world Flat, the range of linearity is 0.2~500 μ g/L, related coefficient (R²) it is 0.9943~0.9997.The mark-on reclaims of 4 different levels Rate is 72.4%~114.8%, relative standard deviation (RSD, n=6) 0.8%~9.5%.Finally to Beijing area acquisition 12 actual water samples are measured, and have 5 kinds of nitrosamine to be detected, content is in 0.9~20.4ng/L.The method sensitivity, selectivity Higher with accuracy, the confirmation suitable for underwater trace nitrosamine detects.

With reference to the accompanying drawing to nitrosamine Sensitive Determination method in the water of the invention based on high resolution mass spec make into One step explanation.

Detailed description of the invention

Fig. 1 is total ion chromatogram of 16 kinds of nitrosamine after different chromatography post separations in the present invention；Wherein, each substance Number and consistent in table 1, A:HP-5MS, B:DB-35MS, C:DB-624, D:DB-WAX；

Fig. 2 is the extraction ion stream chromatogram of 18 kinds of nitrosamine substances (containing two kinds of internal standards) in the present invention；

Fig. 3 is that chromatography of the present invention and mass spectrometry parameters optimize comparison diagram；A: ion source temperature, B: flow rate of carrier gas, C: pulse pressure Power.

Specific embodiment

One, experimental section

1. instrument and reagent

Q Exactive GC Orbitrap type gas-chromatography-quadrupole rod-electrostatic field Orbitrap mass spectrometer, is furnished with TriPlus RSH autosampler (Thermo Fisher company, the U.S.)；7890N-5977B type gas chromatograph-mass spectrometer (beauty Agilent company, state)；TurboVap II type automatic nitrogen blows concentrating instrument (Biotage company, the U.S.)；Solid-phase extraction device (beauty Supelco company, state)；Chromabond Easy, Chromabond HR-P extraction column (500mg, 6mL, German MN company)； Supelclean ENVI-Chrom P extraction column (250mg, 6mL, Supelco company, the U.S.).

16 kinds of nitrosamine and 2 kinds of internal standard NDMA-d₆And NDPA-d₁₄Standard items purchased from TCI, Sigma, The suppliers such as Dr.Ehrenstorfer, Manhage, TRC, purity are all larger than 95%；N-hexane, ethyl acetate, acetone, methanol (chromatographically pure, J.T.Baker company, the U.S.)；Anhydrous sodium sulfate (analyzes pure, Beijing chemical reagent Co., Ltd)；Experimental water For the ultrapure water prepared through Milli-Q purification system (Millipore company, the U.S.).

2. standard solution is prepared

50mg standard items are weighed respectively, dissolved with methanol and are settled in 50mL brown volumetric flask, obtain 1000mg/L's Single mark stock solution.The mixing stock solution and 2 kinds of internal standard mixing storages of 16 kinds of N- nitrosamine of 10mg/L are configured to ethyl acetate Standby liquid, further configures the internal standard working solution of 0.5mg/L, -18 DEG C are kept in dark place.Ethyl acetate is used when use as needed It is diluted to the hybrid working solution of 0.01 μ of μ g/L~500 g/L, wherein internal standard NDMA-d₆And NDPA-d₁₄Concentration be 50 μ g/L。

3. Specification Curve of Increasing

The mixing stock solution of 10mg/L is diluted step by step with ethyl acetate, the standard for preparing 0.2~500.0 μ g/L series is molten Liquid, internal standard compound concentration are 50 μ g/L, are measured respectively, and the quota ion peak area of determinand and corresponding interior target are quantified The ratio of ion peak areas draws standard curve as abscissa (x) as ordinate (y), the upper machine concentration of determinand.

4. sample pre-treatments

Standing is mixed after the 0.5mg/L inner mark solution of 50 μ L is added in 1L water sample.Chromabond HR-P Solid Phase Extraction Column successively uses 5mL methanol to activate, 5mL water balance, and water sample is then crossed column with 3mL/min or so flow velocity, after completion of the sample, takes out Dry 1min.It is eluted with 10mL ethyl acetate, collects eluent, anhydrous sodium sulfate is added and is dehydrated, finally blows supernatant liquid nitrogen It is quantitatively concentrated into 0.5mL, is measured for upper machine.

5. testing conditions

Chromatographic condition: DB-35MS chromatographic column (30m × 0.25mm × 0.25 μm)；Carrier gas high-purity helium (99.999%)；Into 1 μ L of sample volume；Pulse Splitless injecting samples, pulse 200kPa, burst length 1min；Flow rate of carrier gas 2.0mL/min；Sample introduction 250 DEG C of temperature, 250 DEG C of transmission line temperature of mouth；Temperature programming: initial temperature is 40 DEG C, with 15 DEG C/min rate after holding 1min 270 DEG C are risen to, 5min is kept.

Mass Spectrometry Conditions: resolution ratio 60000FWHM (200m/z)；EI ionization source, ion source temperature 280Solvent delay 3min；Full scan mode (Full-Scan), 40~300m/z of scanning range.Target is qualitative and fixed in 16 kinds of nitrosamine and 2 kinds Amount ion is shown in Table 1.

The retention time of 1 18 kinds of nitrosamine substances of table (containing 2 kinds of internal standard compounds), qualitatively and quantitatively ion

^aIt indicates with NDMA-d₆It is quantified for internal standard；^bIt indicates with NDPA-d₁₄It is quantified for internal standard；NA^cIndicate data It does not provide.

Two, result and analysis

1. chromatography-mass spectroscopy condition optimizing

Using conventional low resolution makings, 4 kinds of chromatographic columns, (30m × 0.25mm × 0.25 HP-5MS of low pole have been investigated μm), moderately polar DB-35MS (30m × 0.25mm × 0.25 μm) and DB-624 (30m × 0.25mm × 1.4 μm), Qiang Ji Separation situation of the DB-WAX (30m × 0.25mm × 0.25 μm) of property to 16 kinds of nitrosamine.As a result as shown in Figure 1, chromatographic column DB-624 and DB-WAX has preferable separating effect, however DB-624 is low for the response of substance 3/14/15/16, detects Discovery can significantly affect its sensitivity in journey；DB-WAX cannot separate 6/8 two substances, but this two substance prisons having the same Measured ion 106.065 is difficult to detect respectively if not separating；HP-5MS separating effect is worst, and substance 1/14/15 respond it is low； DB-35MS is preferable to the response of each substance, and total outflow chromatographic peak can be efficiently separated by extracting characteristic ion, It does not influence qualitative and quantifies, and chromatographic column better heat stability (340 DEG C).Therefore DB-35MS chromatographic column is selected to carry out subsequent grind Study carefully.

Q Exactive-GC mass spectrograph full scan under 60000 resolution ratio can reach the acquisition speed of 7 spectrograms per second or more Rate makes data obtain enough number of scan points；Simultaneously quality error within 1ppm, ensure that data stability and can By property.European Union EC/657/2002 about mass spectrometry require must reach 4 confirmation points (Identification point, IP), high resolution mass spectrum carries out full scan measurement to accurate mass number, and each ion is defined as 2 confirmation points, and one quantitative The confirmation point of ion and a qualitative ion of auxiliary can reach 4, to realize simultaneous quantitative and qualitative confirmation.16 kinds of nitrous Amine and 2 kinds of internal standard compounds quantitative and qualitative ion is assisted to be shown in Table 1, the extraction ion flow graph of each substance is shown in Fig. 2.

Higher sensitivity in order to obtain, for mass ions source temperature, chromatography flow rate of carrier gas, input mode and pulse Pressure is optimized.By Fig. 3 A as it can be seen that each substance peak area increases with the raising of ion source temperature, kept after 280 DEG C Relatively stable, higher temperature is conducive to improve Ionization Efficiency and appropriate improvement peak trailing phenomenon.Fig. 3 B shows biggish Flow rate of carrier gas helps to improve the appearance time of substance, and then obtains more sharp peak type and reduce peak trailing phenomenon, carrier gas stream Most of substance responds values are higher when 2.0 mL/min of speed.The effect that can be seen that pulse does not shunt from Fig. 3 C is better than not pulse, This is because Pulsed Sampling mode imposes elevated pressures in injection port, substance is enable to rapidly enter chromatographic column, reduced in injection port Decomposition and loss, while being conducive to obtain sharp symmetrical peak type.By optimizing to pulse, discovery exists It peaks when 200kPa, and tends towards stability later, therefore strobe pulse does not shunt and pulse is 200kPa.

2, SPE condition optimizes

It chooses three kinds of SPE columns that filler is styrene diethylene benzene copoly mer and is used for orthogonal test, be respectively Chromabond HR-P, Supelclean ENVI-Chrom P and Chromabond Easy.16 kinds of N- nitrosamine it is just pungent Alcohol-water partition coefficient (lgkow) range is -0.57~3.90, is distributed from water solubility to oil-soluble, therefore have chosen 3 kinds The eluting solvent of different lgkow values is n-hexane, ethyl acetate and acetone respectively, and wherein n-hexane (3.29) is lipophilicity, Ethyl acetate (0.86) is lipophilic while having certain hydrophily, and acetone (- 0.24) is hydrophily.

Four factors, three horizontal quadrature table (L9 (34)) is selected to optimize SPE condition, experimental design is shown in Table 2, examines Examine the 100mL aqueous solution that 1 μ g/L of content of nitrosamines is extracted under each experiment condition (being converted into solution concentration to be measured is 200 μ g/L) Rate of recovery situation.It the results are shown in Table 3, when making eluting solvent using ethyl acetate, the rate of recovery of each nitrosamine is preferable, Ke Nengyin Water-soluble and oil-soluble target substance preferably can be dissolved and be eluted for ethyl acetate.And n-hexane it is lipophilic compared with By force, poor to hydrophilic nitrosamine such as NDMA dissolubility, cause the rate of recovery of the substance very poor.In 9 orthogonal experiments, The rate of recovery for testing 2 (A1B2C2) is relatively preferable；Range analysis is carried out to experimental result, obtains the best solid phase of each analyte Extraction conditions, in addition to NDBA, the best SPE condition of other nitrosamine is all than more consistent, and only elution amount is distributed in two In a level, i.e. 8mL and 10mL.Confirmatory experiment is carried out later uses Chromabond HR-P column, 8mL and 10mL acetic acid second Ester, the rate of recovery of 10mL ethyl acetate is more preferable as the result is shown, and each substance reaches 88% or more.Selected Solid Phase Extraction as a result, Condition is Chromabond HR-P extraction column, the elution of 10mL ethyl acetate.

2 Solid Phase Extraction orthogonal test factor level table of table

3 Solid Phase Extraction orthogonal experiments of table

3, methodological study

3.1 ranges of linearity, detection limit and lower limit of quantitation

By the mixed standard solution (internal standard containing same concentrations) of various concentration, by low concentration to high concentration successively sample introduction, Draw standard curve.The detection limit that 16 kinds of nitrosamine substances are determined with 3 times of signal-to-noise ratio (S/N >=3), is determined using internal standard method Amount, obtains the quantitative limit of method with S/N >=10, the results are shown in Table 4.The result shows that each substance is in the range of linearity 0.2~500 Coefficient R in μ g/L²>=0.9943, LOD are 0.05~0.5ng/L, and LOQ is 0.1~1.0ng/L.

The range of linearity, related coefficient, detection limit and the quantitative limit of 4 16 kinds of nitrosamine substances of table

The 3.2 method rate of recovery and precision

The mixed mark of nitrosamine by adding 4 various concentrations in blank water sample, does 6 times in parallel.As seen from the results in Table 5, Method for different material the rate of recovery between 72.4%~114.8%, relative standard deviation (RSD, n=6) is 0.8% Between~9.5%.

Compared with the detection method of nitrosamine in reported water (table 6), the method established herein covers nitrosamine substance Quantity more (16 kinds), detection limit low (0.05~0.5ng/L), the rate of recovery are preferable, more crucially by using high-resolution matter Spectrum detection, each substance is qualitative and quota ion quality error is respectively less than 1.839ppm, ensure that the stability of data and reliable Property, and reach 4 confirmation points as defined in European Union EC/657/2002, therefore when carrying out the detection of trace nitrosamine, method can Matrix interference is effectively excluded, higher accuracy and sensitivity are had both.

The rate of recovery and precision of 5 16 kinds of nitrosamine of table

Nitrosamine detection document comparison in table 6 and existing water

The detection of 3.3 actual water samples

Using this method, to 12 of the different regions such as Dongcheng, Haidian, southern exposure, Shijingshan, Tongzhou, Daxing in Beijing Originally water sample is measured and (is shown in Table 7).As a result 5 kinds of nitrosamine of NMPhA, NEPhA, NMOR, NDPhA, NDBzA have been detected, Middle NMOR only has detection in S1 (sample 1), is 0.9ng/L, lower than Germany limitation 10ng/L；And for the other of detection Nitrosamine there is no limitation requirement both at home and abroad at present, need to pay close attention to it.

7 actual water sample testing result of table

The method of the present invention establishes the organophosphorous pesticides high resolution mass spectrum inspection of 16 kinds of trace nitrosamine in drinking water Survey method.Under the instrument testing conditions and SPE condition of optimization, the detection limit (LOD) of 16 kinds of substances is only 0.05~ 0.50ng/L, it is horizontal far below the limitation of current various countries, while high resolution mass spectrum possesses the Mass accuracy of superelevation, each substance prison The mass number of measured ion is accurate to 0.00001, quality error≤1.839ppm, because the method have very high selectivity and Accuracy, the confirmation suitable for underwater trace nitrosamine detects, while also providing reference for the detection of other trace materials.

Embodiment described above only describe the preferred embodiments of the invention, not to model of the invention It encloses and is defined, without departing from the spirit of the design of the present invention, those of ordinary skill in the art are to technical side of the invention The various changes and improvements that case is made should all be fallen into the protection scope that claims of the present invention determines.

Claims (6)

1. a kind of nitrosamine Sensitive Determination method in water based on high resolution mass spec, characterized by the following steps: Water sample is after sample pre-treatments, using chromatography post separation, high resolution mass spectrum full scan mode detection, inner mark method ration, institute Stating sample pre-treatments includes that solid phase extraction concentration and nitrogen blow quantitative concentration.

2. nitrosamine Sensitive Determination method, feature exist in the water according to claim 1 based on high resolution mass spec It is mixed after specifically comprising the following steps: to be added the 0.5mg/L inner mark solution of 50 μ L in: the sample pretreatment process in 1L water sample Even standing, Chromabond HR-P solid-phase extraction column successively use 5mL methanol to activate, 5mL water balance, then by water sample with 3mL/ Min or so flow velocity crosses column, after completion of the sample, drains 1min, is eluted with 10mL ethyl acetate, collects eluent, anhydrous sulphur is added Sour sodium is dehydrated, and is finally blown supernatant liquid nitrogen and is quantitatively concentrated into 0.5mL, is measured for upper machine.

3. nitrosamine Sensitive Determination method, feature exist in the water according to claim 2 based on high resolution mass spec It is that N-Nitrosodimethylamine, N- nitroso Methylethyl amine, N-Nitrosodiethylamine, N- nitroso two are different in: the nitrosamine Propylamine, N- nitroso di-n-propylamine, N- nitroso-methylphenylamine, N- nitroso di-iso-butylmanice, N- nitroso-ethylaniline, N- nitrosopyrolidine, N-nitrosomorpholine, N-nitroso-piperidine, N- nitroso dibutyl amine, N nitrosodiphenyl amine, N- nitrous Base dicyclohexylamine, N- nitroso-N.N (3.5.5- trimethyl) amine and N- nitroso dibenzyl amine.

4. nitrosamine Sensitive Determination method, feature exist in the water according to claim 3 based on high resolution mass spec In: chromatographic condition is as follows: DB-35MS chromatographic column, 30m × 0.25mm × 0.25 μm；Carrier gas high-purity helium, 99.999%；Sample introduction 1 μ L of volume；Pulse Splitless injecting samples, pulse 200kPa, burst length 1min；Flow rate of carrier gas 2.0mL/min；Injection port temperature 250 DEG C, 250 DEG C of transmission line temperature of degree；Temperature programming: initial temperature is 40 DEG C, is risen to after keeping 1min with 15 DEG C/min rate 270 DEG C, keep 5min.

5. nitrosamine Sensitive Determination method, feature exist in the water according to claim 4 based on high resolution mass spec In: Mass Spectrometry Conditions are as follows: resolution ratio 60000FWHM, 200m/z；EI ionization source, 280 DEG C of ion source temperature；Solvent delay 3min； Full scan mode, 40~300m/z of scanning range.

6. nitrosamine Sensitive Determination method, feature exist in the water according to claim 5 based on high resolution mass spec In target is qualitative in: 16 kinds of nitrosamine and 2 kinds and quota ion is shown in Table 1:

1 16 kinds of nitrosamine substances of table and the retention time of two kinds of internal standard compounds, qualitatively and quantitatively ion

^aIt indicates with NDMA-d₆It is quantified for internal standard；^bIt indicates with NDPA-d₁₄It is quantified for internal standard；NA^cIndicate that data do not mention For.