Navigation Links
Determination of N-nitrosamines in Baby Bottle Rubber Teats by Liquid Chromatography-Atmospheric Pressure Chemical Ionization Mass Spectrometry

e rubber teats from each of the different formulations were cut up and extracted with methylene chloride. The extract solution was made basic, and the methylene chloride was distilled off. An additional volume of the aqueous phase was distilled into a separatory funnel and extracted with methanol. The extract was concentrated to a volume of 1 mL.

The HPLC system was a Perkin-Elmer Series 200 autosampler and micro pumps. A Keystone Scientific Inertsil ODS2 column (150 X 4.6 mm) was used with a water-methanol gradient increasing from 80% methanol to 90% methanol over 5 minutes at a flow rate of 1.0 mL/min. Both standards and samples were prepared in methanol. Injection volumes were 20 μL. The MRM optimization program of the Analyst software was utilized to automatically determine optimal product ions, as well as correct settings for lens voltages and collision energies for each MRM transition. These values are shown in Table 1.

Results

Figure 1 shows the XIC of the 1 ppb nitrosamine standard mixture. The signal to noise (S/N) ratio varies according to the analyte. The NDMA had the lowest S/N with a value of 3.0. The highest S/N was obtained by the NMEA with a value of 37.8. Other S/N values observed were NPYR (6.0), NDEA (8.6), NPIP (13.8), and NMOR (13.6). The S/N calculation within the Analyst software requires two regions to be selected in the chromatogram; a region containing the noise and a region containing the peak of interest. The algorithm first subtracts the average backgroundsignal intensity from the background and then divides the subtracted signal by 3 times the standard deviation of the noise region.

signal intensity from the background and then divides the subtracted signal by 3 times the standard deviation of the noise region. Standards containing 1, 5, 10, 50, 100, 500, 1000, and 2000 ppb (ng/mL) of the ni
'"/>

Source:


Page: All 1 2 3

Related biology technology :

1. Structural Determination of Flavonoids Using MSn
2. Total Cellular Protein Determination Using the DC Protein Assay
3. Simultaneous Determination of Residues of Approximately 100 Pesticides and Metabolites in Fruit and Vegetables by LC/MS/MS
4. Determination of Polar Organophosphorus Pesticides in Aqueous Samples by Direct Injection Using HPLC/MS/MS
5. Determination of the Chloramphenicol residues in milk and milk products using LC/MS/MS
6. A Microtiter-based Assay for the Determination of ID50s of b-lactamase Inhibitors Employing Reporter Substrates Detected at UV or Visible Wavelengths (MaxLine Application Note #20)
7. Determination of Acepromazine and its Major Metabolite in Equine Serum by LC-MS/MS using the Finnigan LCQ Deca XP Plus Ion Trap Mass Spectrometer
8. Chemical Stability of the Brinkmann Bottletop Dispenser and the Brinkmann Bottletop Buret
9. Ergonomics and Liquid Handling How can BrinkmannTM Help ?
10. Sciclone ALH 3000 Liquid Handler: Functional Characterization of the High Volume Head - Part 1: Plate-to-Plate Precision Testing
11. Precision Testing for the Sciclone Advanced Liquid Handler Z8 Option
Post Your Comments:
(Date:4/25/2015)... (PRWEB) April 25, 2015 Join us ... 29th: Analyzing Kinase Inhibitor Residence Times using the Transcreener® ... of inhibitor residence times is increasingly being incorporated into ... can result in improved efficacy, increased therapeutic window and ... determined using immobilized ligand methods such surface plasmon resonance, ...
(Date:4/24/2015)... Top student social innovators from the ... universities, including UCSD and SDSU, will pitch their impact ... national and nonprofit companies for an opportunity to win ... Social Innovation Challenge 2015 . , The 2015 Social ... addressing a diverse range of issues including poverty, education, ...
(Date:4/24/2015)... SD and Tempe, AZ (PRWEB) April 24, 2015 ... Technology and Arizona State University (ASU) have entered into ... joint projects. , A memorandum of agreement signed by ... long distance learning, student success and other services particularly, ... resources. , “We have complementary strengths and a ...
(Date:4/24/2015)... California (PRWEB) April 24, 2015 ... key milestones in its allogeneic stem-cell product development ... to properly reflect the corporate strategic direction. , ... allogeneic (donor) adipose stem cell development program has ... of our cGMP manufacturing facility and hiring of ...
Breaking Biology Technology:BellBrook Labs Webinar: Analyzing Kinase Inhibitor Residence Times using the Transcreener® ADP Assay 25th Annual Social Innovation Challenge at University of San Diego - Students Pitch to Live Judging Panel to Take Home $75K 25th Annual Social Innovation Challenge at University of San Diego - Students Pitch to Live Judging Panel to Take Home $75K 3South Dakota Mines, Arizona State University Pave Way for Cooperative Research 2Vet-Stem, Inc. Meets New Milestones and Changes Name to VetStem Biopharma 2
... 28 Boston,Scientific Corporation (NYSE: BSX ) ... that Boston Scientific has completed its acquisition of ... April 16.,Under the terms of the transaction, all ... per share in cash, for a total of,approximately ...
... N.J., May 28 National Stem Cell,Holding, Inc. (OTC: ... steps to,change its name to Proteonomix, Inc. The change ... Michael Cohen, President/CEO, stated: "Our new name reflects the ... development stage and,commencing the commercialization of our technologies. These ...
... Provides Additional Global Corporate Finance, Management and ... Manufacturing ... (TSX: NVN) announced today the appointment of Gordon H.,Busenbark to ... chief financial officer of Xytis Pharmaceuticals, a privately,held development-stage specialty ...
Cached Biology Technology:Boston Scientific Completes Acquisition of CryoCor 2Boston Scientific Completes Acquisition of CryoCor 3National Stem Cell Holding, Inc. Announces the Change of Its Name to Proteonomix, Inc. 2National Stem Cell Holding, Inc. Announces the Change of Its Name to Proteonomix, Inc. 3Nventa Appoints Gordon H. Busenbark to Board of Directors 2
(Date:3/20/2015)... --Research and Markets ( http://www.researchandmarkets.com/research/rswjb4/hand_geometry ) has announced ... Business Report" report to their offering. This ... Thousands. The report provides separate comprehensive analytics for the US, ... Europe , Asia-Pacific , ... Annual estimates and forecasts are provided for the ...
(Date:3/19/2015)... March 19, 2015  NXT-ID, Inc. (NASDAQ: NXTD ... on the growing mobile commerce market, announces its biometric payment ... clip that aired this week on Washington DC,s ... In a segment "The Next Great Thing", host ... way to pay, and ,a really big breakthrough in mobile ...
(Date:3/17/2015)... March 17, 2015 Emotient, the leader ... today announced general availability of Emotient Analytics ... the analysis of facial expressions. The system analyzes ... content, products and services. It delivers audience response ... sentiment - as derived from facial evidence of ...
Breaking Biology News(10 mins):Hand Geometry - Global Strategic Business Report 2015: An Essential Security Component for both Government & Enterprise Sector 2Hand Geometry - Global Strategic Business Report 2015: An Essential Security Component for both Government & Enterprise Sector 3Hand Geometry - Global Strategic Business Report 2015: An Essential Security Component for both Government & Enterprise Sector 4NXT-ID's Wocket Smart Wallet Featured on Fox News Segment, "The Next Great Thing" 2NXT-ID's Wocket Smart Wallet Featured on Fox News Segment, "The Next Great Thing" 3New Emotient Web Service Measures Audience Response Using On-Demand Facial Expression Analysis 2New Emotient Web Service Measures Audience Response Using On-Demand Facial Expression Analysis 3New Emotient Web Service Measures Audience Response Using On-Demand Facial Expression Analysis 4
... Fluctuations in penguin populations in the Antarctic are linked more ... to changes in their habitats, according to a new study ... Academy of Sciences . Funded in part by the Lenfest ... "winners" of changing conditions, such as large-scale ice melting, may ...
... NEW YORK (April 11, 2011) -- Weill Cornell Medical ... Surgeons have announced that The Mortimer D. Sackler, M.D. ... awarded to The Rockefeller University,s Dr. Fernando Nottebohm for ... the discovery of neuronal replacement. Dr. Nottebohm is ...
... FINDINGS: Certain differentiated cells in breast tissue can spontaneously ... researchers. Until now, scientific dogma has stated that differentiation ... return to the flexible stem-cell state on their own. ... well as for breast cancer cells. RELEVANCE: ...
Cached Biology News:Penguins that shun ice still lose big from a warming climate 2Sackler Prize awarded to pioneering neuroscientist 2Sackler Prize awarded to pioneering neuroscientist 3Scientists identify a surprising new source of cancer stem cells 2Scientists identify a surprising new source of cancer stem cells 3
MAb to Vasopressin Preservative: NaN3...
Rabbit Anti-Human Secretory Carrier Membrane Protein 2 (SCAMP2 Polyclonal AntibodyOther Sub-Family: not assigned-Other Applications: Western Blot...
... bottoms,• Nonreversible lids with ... contamination,• Individual alphanumerical codes ... footprint for ease in ... cell attachment,• Sterilized by ...
... a G1 cyclin required for G1-phase progression ... proto-oncogene. cyclin D2 can phosphorylate pRB ... Reactivity: Human, Mouse, and Rat. ... particularly well suited for neutralization of cyclin ...
Biology Products: