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The '''Kendrick mass''' is defined by setting the mass of a chosen molecular fragment, typically CH<sub>2</sub>, to an integer value in [[atomic mass units]]. It is different from the IUPAC definition, which is based on setting the mass of <sup>12</sup>C isotope to exactly 12 u. The Kendrick mass is often used to identify homologous compounds differing only by a number of base units in high resolution [[mass spectra]].<ref name='Kendrick 1963'>{{Citation|doi=10.1021/ac60206a048|title=A mass scale based on CH<sub>2</sub> = 14.00000 for high resolution mass spectrometry of organic compounds|journal=[[Anal. Chem.]]|year=1963|first=Edward|last=Kendrick|coauthors=|volume=35|issue=13|pages=2146–2154|id= |doi=10.1021/ac60206a048|format=|postscript=. }}</ref><ref name="pmid14730994">{{Citation |author=Marshall AG, Rodgers RP |title=Petroleomics: the next grand challenge for chemical analysis |journal=[[Acc. Chem. Res.]] |volume=37 |issue=1 |pages=53–9 |date=January 2004 |pmid=14730994 |doi=10.1021/ar020177t |url= |postscript=.}}</ref> This definition of mass was first suggested in 1963 by [[chemist]] Edward Kendrick, and it has been adopted by scientists working in the area of high-resolution [[mass spectrometry]], environmental analysis, [[proteomics]], petroleomics, [[metabolomics]], etc.
Baron Haussmann got a Parisian thoroughfare  [http://tinyurl.com/kecvhhb cheap ugg boots] named after himself in the mid-nineteenth century by reconfiguring the city's circulatory road systems into wide, grand avenues.<br><br>The idea was to widen streets and prevent blockades and riots. It didn't entirely work, but was a noble effort.<br>What did it take for Chanel to get their own street? Well, if you pump vast amounts of cash into building a set that's a photographic facsimile of a Parisian rue, you can call it whatever you damn well want. So, the models at Karl Lagerfeld's spring/summer 2015 Chanel show sauntered in groups down the centre of "Boulevard Chanel," easily chatting amongst themselves.<br><br>A few carried boomboxes packed into chic Chanel handbags, the tinny sound reverberating until the thumping main soundtrack took over. "I'm every woman," warbled Whitney Houston, at one point, "It's all in me."<br>She could have been singing about the collection because, in typical Lagerfeld style, it was all in there. Wide trousers, tunics, print, plain, military, pinstripes, sweaters, Gisele in a striped cardigan and something suspiciously close to a pair of Chanel Uggs. All present and correct, on flat shoes, women striding meaningfully off to work.<br><br>Which, in the fashion world, means the end of the (catwalk) road and back. [http://tinyurl.com/kecvhhb discount ugg boots] There were also, obviously, plenty of bags, printed with faux-politicised slogans like "F�ministe mais Feminine," or "Votez Coco." Chanel Spring/Summer 2015 show by German designer Karl Lagerfeld during the Paris Fashion Week <br>There's been an undercurrent of women dressing women this week in [http://tinyurl.com/kecvhhb cheap ugg boots] Paris - Lagerfeld isn't a woman, obviously. But he does operate under the mantle of Coco Chanel, who tied her fashion to the feminist cause, even if she didn't realise it. Clothes, she stated, must be logical.<br><br>A button should have a buttonhole, and should work. Pockets should be real.<br>Chanel glorified function over form, or at least the ideal twinning together of the two. Her clothes addressed her own reality, the demands of the clothes she wanted to wear, which found resonance in women in the wider world. It was as simple as the chain handle on her 2.55 handbag, leaving the hands free to get on with something else, or the fact said bag was originally lined in burgundy, to make it easier to find your stuff inside.<br><br>Gisele Bundchen on the Chanel spring/summer 2015 catwalk<br>Chanel's bag was a form of protest against the impracticality of everyday fashion in the mid fifties - she loathed the corsets and petticoats of the New Look, for instance, and following her 1954 comeback railed against it everyday she could. Likewise, Lagerfeld's faux-sloganeering on his pouches and pochettes were portents of protest to come.<br><br>After the show finished, models returned to the stage (or rather, the street) [http://www.google.co.uk/search?hl=en&gl=us&tbm=nws&q=brandishing+placards&gs_l=news brandishing placards] daubed with [http://Pinterest.com/search/pins/?q=pronouncements pronouncements] like "Make fashion not war" (fair enough), or "Tweed is better than tweet" (a bit of pointless punnery). Their clarion call, via megaphone? "What do we want? Tweed!" Okay.<br>Gisele Bundchen leads the unusual finale at Chanel show <br><br>A few of the models had the good grace to look embarrassed; most seemed to think it was a bit of a laugh. Which also summarised the audience's reaction. Maybe Lagerfeld was cynically poking fun at the whole idea of fashion commenting on culture at large, intentionally reducing its protests to facile fashion commandments rather than an attempt at genuine change.<br><br>But the co-opting of protest polemic as a tool instigating you to  [http://tinyurl.com/kecvhhb http://tinyurl.com/kecvhhb] buy, as opposed to question why, struck a bum note. Was tweed all we should read into this collection? Should a fashion show just make you want to go out and charge something, rather than change something?<br><br>That's not a judgement on the clothes, which were fine. They were playful, colourful, vibrant. The clusters of models  [http://tinyurl.com/kecvhhb http://tinyurl.com/kecvhhb] walking together had a bounce and an energy, as well as a reflection of the everyday world. There was something compelling about our odd transportation into a unreal "everyday" Paris street - which ended up feeling more like a scene from Paris When It Sizzles, a choreographed and entirely false occurrence for the benefit of a few thousand onlookers, than  [http://tinyurl.com/kecvhhb discount ugg boots] a real slice of Paris life.<br><br>Cara Delevingne presents a creation for Chanel during the 2015 Spring/Summer ready-to-wear collection fashion show in Paris <br>Perhaps Chanel's riot was inspired those real-life scenes last season, when the fashion press tore apart the Supermarket the label erected in the middle of the Grand Palais - the whole thing was cordoned off with riot barriers this time, just in case. But why riot if you've got nothing to say?<br><br>Chanel wasn't making a political statement, they were just attracting attention by making a great deal of noise and fuss. It was the artifice of anarchy. A joke, sure, but not an especially funny one.<br>And it overshadowed the real message of the clothes on show, which in their diversity and lack of fashion diktat, did have something of a feminist, Chanel-for-all message running through them, like the flecks of bright colour through those tweeds.<br><br>Paris Fashion Week spring/summer 2015<br>Looking through the ranks of the audience, and seeing the Chanel jacket crop up again and again, from front-row couture client to standing fashion students, you were arrested by the continuing universality of that style Coco Chanel herself originated. It's a great jacket, but it's not worth rioting over.<br><br>Haven't we all - fashion designers included - got something more interesting to say than that?<br>In short? Nice show. Shame it all had to end like that.
 
==Definition==
According to the procedure outlined by Kendrick, the mass of CH<sub>2</sub> is defined as exactly 14 Da, instead of the IUPAC mass of 14.01565 Da.<ref>{{Citation | last1 = Mopper | first1 = Kenneth | last2 = Stubbins | first2 = Aron | last3 = Ritchie | first3 = Jason D. | last4 = Bialk | first4 = Heidi M. | last5 = Hatcher | first5 = Patrick G. | title = Advanced Instrumental Approaches for Characterization of Marine Dissolved Organic Matter:  Extraction Techniques, Mass Spectrometry, and Nuclear Magnetic Resonance Spectroscopy | journal = Chemical Reviews | volume = 107 | issue = 2 | pages = 419 | year = 2007 | pmid = 17300139 | doi = 10.1021/cr050359b}}</ref><ref>{{Citation | last1 = Meija | first1 = Juris | title = Mathematical tools in analytical mass spectrometry | journal = Analytical and Bioanalytical Chemistry | volume = 385 | issue = 3 | pages = 486 | year = 2006 | pmid = 16514517 | doi = 10.1007/s00216-006-0298-4}}</ref>
 
To convert an IUPAC mass of a particular compound to the Kendrick mass, the equation
 
: <math>\textrm{Kendrick~mass} = \textrm{IUPAC~mass} \times \frac{14.00000}{14.01565} </math>.
 
is used.<ref name="pmid14730994" /><ref name="Headley 2009">{{Citation | last1 =Headley | first1 =John V. | last2 =Peru | first2 =Kerry M. | last3 =Barrow | first3 =Mark P. | title =Mass spectrometric characterization of naphthenic acids in environmental samples: A review | journal =Mass Spectrometry Reviews | volume =28 | issue =1 | pages =121 | year =2009 | pmid =18677766 | doi =10.1002/mas.20185}}</ref><ref>{{Citation | last1 =Ohta | first1 =Daisaku | last2 =Kanaya | first2 =Shigehiko | last3 =Suzuki | first3 =Hideyuki | title =Application of Fourier-transform ion cyclotron resonance mass spectrometry to metabolic profiling and metabolite identification | journal =Current Opinion in Biotechnology | volume =21 | issue =1 | pages =35 | year =2010 | pmid =20171870 | doi =10.1016/j.copbio.2010.01.012}}</ref><ref name="Reemtsma 2009">{{Citation | last1 =Reemtsma | first1 =Thorsten | title =Determination of molecular formulas of natural organic matter molecules by (ultra-) high-resolution mass spectrometryStatus and needs | journal =Journal of Chromatography A | volume =1216 | issue =18 | pages =3687 | year =2009 | pmid =19264312 | doi =10.1016/j.chroma.2009.02.033}}</ref> The mass in [[dalton (unit)|dalton units]] (''Da'') can be converted to the Kendrick scale by dividing by 1.0011178.<ref name='Kendrick 1963' /><ref>{{Citation | last1 = Panda | first1 = Saroj K. | last2 = Andersson | first2 = Jan T. | last3 = Schrader | first3 = Wolfgang | title = Mass-spectrometric analysis of complex volatile and nonvolatile crude oil components: a challenge | journal = Analytical and Bioanalytical Chemistry | volume = 389 | issue = 5 | pages = 1329 | year = 2007 | pmid = 17885749 | doi = 10.1007/s00216-007-1583-6}}</ref>
 
Other groups of atoms in addition to CH<sub>2</sub> can be used define the Kendrick mass, for example CO<sub>2</sub>, H<sub>2</sub>, H<sub>2</sub>O, and O.<ref name="Reemtsma 2009" /><ref>{{citation|last1=Kim|first1=Sunghwan|last2=Kramer|first2=Robert W.|last3=Hatcher|first3=Patrick G.|title=Graphical Method for Analysis of Ultrahigh-Resolution Broadband Mass Spectra of Natural Organic Matter, the Van Krevelen Diagram|journal=Analytical Chemistry|volume=75|issue=20|pages=5336|year=2003|pmid=14710810|doi=10.1021/ac034415p }}</ref><ref>{{citation|last1=Nizkorodov|first1=Sergey A.|last2=Laskin|first2=Julia|last3=Laskin|first3=Alexander|title=Molecular chemistry of organic aerosols through the application of high resolution mass spectrometry|journal=Physical Chemistry Chemical Physics|volume=13|pages=3612|year=2011|doi=10.1039/C0CP02032J|bibcode = 2011PCCP...13.3612N |issue=9|pmid=21206953}}</ref> In this case, the Kendrick mass for a family of compounds F is given by
 
:<math>\textrm{Kendrick~mass~(F)} = \textrm{(observed~mass)} \times \frac{\textrm{nominal~mass~F}}{\textrm{exact~mass~F}}</math>.
 
For the hydrocarbon analysis, F=CH<sub>2</sub>.
 
A recent publication has suggested that Kendrick mass be expressed in Kendrick units with symbol ''Ke''.<ref>{{Citation| last1 =Junninen| first1 =H.| last2 =Ehn| first2 =M.| last3 =Petäjä| first3 =T.| last4 =Luosujärvi| first4 =L.| last5 =Kotiaho| first5 =T.| last6 =Kostiainen| first6 =R.| last7 =Rohner| first7 =U.| last8 =Gonin| first8 =M.| last9 =Fuhrer| first9 =K.| title =A high-resolution mass spectrometer to measure atmospheric ion composition| journal =Atmospheric Measurement Techniques| volume =3| pages =1039| year =2010| doi =10.5194/amt-3-1039-2010| last10 =Kulmala| first10 =M.| last11 =Worsnop| first11 =D. R.| issue =4}}</ref>
 
==Kendrick mass defect==
The Kendrick [[mass defect]] is defined as the [[exact mass|exact]] Kendrick mass subtracted from the [[Nominal mass|nominal]] (integer) Kendrick mass:<ref name="pmid11605846">{{Citation |author=Hughey CA, Hendrickson CL, Rodgers RP, Marshall AG, Qian K |title=Kendrick mass defect spectrum: a compact visual analysis for ultrahigh-resolution broadband mass spectra |journal=[[Anal. Chem.]] |volume=73 |issue=19 |pages=4676–81 |date=October 2001 |pmid=11605846 |doi= 10.1021/ac010560w|url= |postscript=.}}</ref><ref name="Marshall2008">{{Citation |last1=Marshall |first1=A. G. |last2=Rodgers |first2=R. P. |title=Mass Spectrometry Special Feature: Petroleomics: Chemistry of the underworld |journal=Proceedings of the National Academy of Sciences |volume=105 |pages=18090 |year=2008 |doi=10.1073/pnas.0805069105 |postscript=.|bibcode = 2008PNAS..10518090M |issue=47 }}</ref>
 
:<math>\textrm{Kendrick~mass~defect}= \textrm{nominal~Kendrick~mass} - \textrm{Kendrick~mass}</math>
 
In recent years the equation has changed due to rounding errors to:
 
:<math>\textrm{Kendrick~mass~defect}= \textrm{nominal~mass} - \textrm{Kendrick~exact~mass}</math>
 
The members of an [[alkylation]] series have the same [[degree of unsaturation]] and number of heteroatoms ([[nitrogen]], [[oxygen]] and [[sulfur]]) but differ in the number of CH<sub>2</sub> units. Members of an alkylation series have the same Kendrick mass defect.
 
The Kendrick mass defect has also been defined as
 
:<math>\textrm{Kendrick~mass~defect}= (\textrm{nominal~Kendrick~mass} - \textrm{Kendrick~mass}) \times 1{,}000</math> .<ref>{{citation|last1=Panda|first1=Saroj K.|last2=Andersson|first2=Jan T.|last3=Schrader|first3=Wolfgang|title=Mass-spectrometric analysis of complex volatile and nonvolatile crude oil components: a challenge|journal=Analytical and Bioanalytical Chemistry|volume=389|issue=5|pages=1329|year=2007|pmid=17885749|doi=10.1007/s00216-007-1583-6}}</ref>
 
The abbreviations ''KM'' and ''KMD'' have been used for Kendrick mass and Kendrick mass defect, respectively. In some definitions, the KMD <ref>{{citation|last1=Reemtsma|first1=Thorsten|title=Determination of molecular formulas of natural organic matter molecules by (ultra-) high-resolution mass spectrometry Status and needs|journal=Journal of Chromatography A|volume=1216|issue=18|pages=3687|year=2009|pmid=19264312|doi=10.1016/j.chroma.2009.02.033}}</ref>
 
==Kendrick mass analysis==
[[File:Kendrick plot.gif|thumb|right|300 px|Plot of Kendrick mass defect as function of Kendrick mass; horizontal lines indicate common repeat units. Each dot in the plot corresponds to a peak measured in a mass spectrum.]]
 
In a Kendrick mass analysis, the Kendrick mass defect is plotted as function of nominal Kendrick mass for ions observed in a mass spectrum.<ref name="Headley 2009" /> Ions of the same family, for example the members of an alkylation series, have the same Kendrick mass defect but different nominal Kendrick mass and are positioned along a horizontal line on the plot. If the composition of one ion in the family can be determined, the composition of the other ions can be inferred. Horizontal lines of different Kendrick mass defect correspond to ions of different composition, for example degree of saturation or heteroatom content.
 
A Kendrick mass analysis is often used in conjunction with a [[Van Krevelen diagram]], a two- or three- dimensional graphical analysis in which the elemental composition of the compounds are  plotted according to the atomic ratios H/C, O/C, or N/C.<ref name="Reemtsma 2009" /><ref>{{citation|last1=Wu|first1=Zhigang|last2=Rodgers|first2=Ryan P.|last3=Marshall|first3=Alan G.|title=Two- and Three-Dimensional van Krevelen Diagrams:  A Graphical Analysis Complementary to the Kendrick Mass Plot for Sorting Elemental Compositions of Complex Organic Mixtures Based on Ultrahigh-Resolution Broadband Fourier Transform Ion Cyclotron Resonance Mass Measurements|journal=Analytical Chemistry|volume=76|issue=9|pages=2511|year=2004|pmid=15117191|doi=10.1021/ac0355449}}</ref>
 
== Notes ==
{{Reflist}}
 
{{DEFAULTSORT:Kendrick Mass}}
[[Category:Units of mass]]
[[Category:Metrology]]
[[Category:Mass spectrometry]]

Latest revision as of 21:11, 6 November 2014

Baron Haussmann got a Parisian thoroughfare cheap ugg boots named after himself in the mid-nineteenth century by reconfiguring the city's circulatory road systems into wide, grand avenues.

The idea was to widen streets and prevent blockades and riots. It didn't entirely work, but was a noble effort.
What did it take for Chanel to get their own street? Well, if you pump vast amounts of cash into building a set that's a photographic facsimile of a Parisian rue, you can call it whatever you damn well want. So, the models at Karl Lagerfeld's spring/summer 2015 Chanel show sauntered in groups down the centre of "Boulevard Chanel," easily chatting amongst themselves.

A few carried boomboxes packed into chic Chanel handbags, the tinny sound reverberating until the thumping main soundtrack took over. "I'm every woman," warbled Whitney Houston, at one point, "It's all in me."
She could have been singing about the collection because, in typical Lagerfeld style, it was all in there. Wide trousers, tunics, print, plain, military, pinstripes, sweaters, Gisele in a striped cardigan and something suspiciously close to a pair of Chanel Uggs. All present and correct, on flat shoes, women striding meaningfully off to work.

Which, in the fashion world, means the end of the (catwalk) road and back. discount ugg boots There were also, obviously, plenty of bags, printed with faux-politicised slogans like "F�ministe mais Feminine," or "Votez Coco." Chanel Spring/Summer 2015 show by German designer Karl Lagerfeld during the Paris Fashion Week
There's been an undercurrent of women dressing women this week in cheap ugg boots Paris - Lagerfeld isn't a woman, obviously. But he does operate under the mantle of Coco Chanel, who tied her fashion to the feminist cause, even if she didn't realise it. Clothes, she stated, must be logical.

A button should have a buttonhole, and should work. Pockets should be real.
Chanel glorified function over form, or at least the ideal twinning together of the two. Her clothes addressed her own reality, the demands of the clothes she wanted to wear, which found resonance in women in the wider world. It was as simple as the chain handle on her 2.55 handbag, leaving the hands free to get on with something else, or the fact said bag was originally lined in burgundy, to make it easier to find your stuff inside.

Gisele Bundchen on the Chanel spring/summer 2015 catwalk
Chanel's bag was a form of protest against the impracticality of everyday fashion in the mid fifties - she loathed the corsets and petticoats of the New Look, for instance, and following her 1954 comeback railed against it everyday she could. Likewise, Lagerfeld's faux-sloganeering on his pouches and pochettes were portents of protest to come.

After the show finished, models returned to the stage (or rather, the street) brandishing placards daubed with pronouncements like "Make fashion not war" (fair enough), or "Tweed is better than tweet" (a bit of pointless punnery). Their clarion call, via megaphone? "What do we want? Tweed!" Okay.
Gisele Bundchen leads the unusual finale at Chanel show

A few of the models had the good grace to look embarrassed; most seemed to think it was a bit of a laugh. Which also summarised the audience's reaction. Maybe Lagerfeld was cynically poking fun at the whole idea of fashion commenting on culture at large, intentionally reducing its protests to facile fashion commandments rather than an attempt at genuine change.

But the co-opting of protest polemic as a tool instigating you to http://tinyurl.com/kecvhhb buy, as opposed to question why, struck a bum note. Was tweed all we should read into this collection? Should a fashion show just make you want to go out and charge something, rather than change something?

That's not a judgement on the clothes, which were fine. They were playful, colourful, vibrant. The clusters of models http://tinyurl.com/kecvhhb walking together had a bounce and an energy, as well as a reflection of the everyday world. There was something compelling about our odd transportation into a unreal "everyday" Paris street - which ended up feeling more like a scene from Paris When It Sizzles, a choreographed and entirely false occurrence for the benefit of a few thousand onlookers, than discount ugg boots a real slice of Paris life.

Cara Delevingne presents a creation for Chanel during the 2015 Spring/Summer ready-to-wear collection fashion show in Paris
Perhaps Chanel's riot was inspired those real-life scenes last season, when the fashion press tore apart the Supermarket the label erected in the middle of the Grand Palais - the whole thing was cordoned off with riot barriers this time, just in case. But why riot if you've got nothing to say?

Chanel wasn't making a political statement, they were just attracting attention by making a great deal of noise and fuss. It was the artifice of anarchy. A joke, sure, but not an especially funny one.
And it overshadowed the real message of the clothes on show, which in their diversity and lack of fashion diktat, did have something of a feminist, Chanel-for-all message running through them, like the flecks of bright colour through those tweeds.

Paris Fashion Week spring/summer 2015
Looking through the ranks of the audience, and seeing the Chanel jacket crop up again and again, from front-row couture client to standing fashion students, you were arrested by the continuing universality of that style Coco Chanel herself originated. It's a great jacket, but it's not worth rioting over.

Haven't we all - fashion designers included - got something more interesting to say than that?
In short? Nice show. Shame it all had to end like that.