1500:
1512:
555:
347:
669:
331:(the values of the molar absorption coefficient for each species at these wavelengths must also be known). The wavelengths chosen are usually the wavelengths of maximum absorption (absorbance maxima) for the individual species. None of the wavelengths may be an
315:
550:{\displaystyle {\begin{cases}A(\lambda _{1})=\ell \sum _{i=1}^{N}\varepsilon _{i}(\lambda _{1})c_{i},\\\ldots \\A(\lambda _{N})=\ell \sum _{i=1}^{N}\varepsilon _{i}(\lambda _{N})c_{i}.\\\end{cases}}}
580:
1331:
147:
1004:
845:
816:
93:
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1155:
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216:
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1140:
108:
of a material that has only one absorbing species also depends on the pathlength and the concentration of the species, according to the
84:). In older literature, the cm/mol is sometimes used; 1 Mâ‹…cm equals 1000 cm/mol. The molar absorption coefficient is also known as the
1422:
1174:
990:
918:
1543:
1427:
1245:
199:(ln). The molar absorption coefficient is usually decadic. When ambiguity exists, it is important to indicate which one applies.
1442:
1412:
1343:
1277:
1371:
1162:
1059:
1538:
1169:
1074:
63:
664:{\displaystyle \sigma =\ln(10){\frac {10^{3}}{N_{\text{A}}}}\varepsilon \approx 3.82353216\times 10^{-21}\,\varepsilon .}
1303:
1150:
1039:
1459:
934:
Gill, S. C.; von Hippel, P. H. (1989). "Calculation of protein extinction coefficients from amino acid sequence data".
1298:
1267:
1200:
776:
If the molar absorption coefficient is known, it can be used to determine the concentration of a protein in solution.
680:
1449:
1391:
1240:
1112:
206:
absorbing species in a solution, the overall absorbance is the sum of the absorbances for each individual species
1548:
1475:
1454:
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1095:
1516:
1348:
1044:
561:
888:
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117:
1135:
338:
1504:
1376:
1107:
1021:
109:
356:
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170:
75:
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1123:
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187:
is decadic (10-based) or
Napierian (e-based), i.e., defined with respect to the transmission via
59:
1381:
1308:
1282:
951:
914:
565:
196:
943:
859:
830:
333:
188:
47:
17:
797:"Chapter 11 Section 2 - Terms and symbols used in photochemistry and in light scattering"
1532:
947:
766:
855:
826:
1013:
746:
310:{\displaystyle A=\sum _{i=1}^{N}A_{i}=\ell \sum _{i=1}^{N}\varepsilon _{i}c_{i}.}
850:
821:
762:
67:
758:
684:
560:
The molar absorption coefficient (in units of Mcm) is directly related to the
328:
184:
105:
55:
27:
Measure of how strongly a chemical species absorbs a given wavelength of light
854:, 2nd ed. (the "Gold Book") (1997). Online corrected version: (2006–) "
825:, 2nd ed. (the "Gold Book") (1997). Online corrected version: (2006–) "
863:
834:
757:
depends almost exclusively on the number of aromatic residues, particularly
51:
31:
955:
750:
92:, but the use of these alternative terms has been discouraged by the
341:
can be solved to find the concentrations of each absorbing species:
74:), but in practice, quantities are usually expressed in terms of
986:
982:
183:
Different disciplines have different conventions as to whether
324:
absorbing species can be found by measuring the absorbance at
683:
is equal to the molar absorption coefficient divided by the
543:
80:â‹…cm or Lâ‹…molâ‹…cm (the latter two units are both equal to
66:
of molar absorption coefficient is the square metre per
973:
Nikon
MicroscopyU: Introduction to Fluorescent Proteins
975:
includes a table of molar attenuation coefficient of
583:
350:
219:
120:
1468:
1405:
1364:
1357:
1319:
1291:
1233:
1183:
1083:
1020:
804:
Compendium on
Analytical Nomenclature (Orange Book)
663:
549:
309:
141:
765:. Similarly, the molar absorption coefficient of
913:(3rd ed.). New York: Springer. p. 59.
773:can be predicted given the nucleotide sequence.
337:for a pair of species. The set of the following
998:
8:
1070:Vibrational spectroscopy of linear molecules
791:
789:
761:, and can be predicted from the sequence of
1361:
1065:Nuclear resonance vibrational spectroscopy
1005:
991:
983:
1438:Inelastic electron tunneling spectroscopy
1118:Resonance-enhanced multiphoton ionization
654:
645:
621:
611:
605:
582:
531:
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298:
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267:
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230:
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119:
1206:Extended X-ray absorption fine structure
749:, the molar absorption coefficient of a
911:Principles of Fluorescence Spectroscopy
785:
896:Compendium on Analytical Nomenclature
883:Compendium on Analytical Nomenclature
736:= Molar mass of the absorbing species
142:{\displaystyle A=\varepsilon c\ell ,}
46:) is a measurement of how strongly a
7:
1511:
851:Compendium of Chemical Terminology
822:Compendium of Chemical Terminology
25:
1423:Deep-level transient spectroscopy
1175:Saturated absorption spectroscopy
1510:
1499:
1498:
1428:Dual-polarization interferometry
320:The composition of a mixture of
1443:Scanning tunneling spectroscopy
1418:Circular dichroism spectroscopy
1413:Acoustic resonance spectroscopy
1372:Fourier-transform spectroscopy
1060:Vibrational circular dichroism
730:= Molar absorption coefficient
602:
596:
524:
511:
471:
458:
428:
415:
375:
362:
1:
1170:Cavity ring-down spectroscopy
1075:Thermal infrared spectroscopy
724:= Mass absorption coefficient
76:
40:molar attenuation coefficient
1304:Inelastic neutron scattering
948:10.1016/0003-2697(89)90602-7
161:molar absorption coefficient
86:molar extinction coefficient
36:molar absorption coefficient
18:Molar extinction coefficient
1365:Data collection, processing
1241:Photoelectron/photoemission
681:mass absorption coefficient
675:Mass absorption coefficient
1565:
1450:Photoacoustic spectroscopy
1392:Time-resolved spectroscopy
806:. IUPAC. 2002. p. 28.
687:of the absorbing species.
1494:
1476:Astronomical spectroscopy
1455:Photothermal spectroscopy
564:(in units of cm) via the
562:attenuation cross section
909:Lakowicz, J. R. (2006).
876:"Molecular Spectroscopy"
1544:Absorption spectroscopy
1460:Pump–probe spectroscopy
1349:Ferromagnetic resonance
1141:Laser-induced breakdown
936:Analytical Biochemistry
864:10.1351/goldbook.A00044
835:10.1351/goldbook.E02293
1156:Glow-discharge optical
1136:Raman optical activity
1050:Rotational–vibrational
889:"Measuring techniques"
665:
551:
500:
404:
339:simultaneous equations
311:
283:
246:
143:
1377:Hyperspectral imaging
666:
552:
480:
384:
312:
263:
226:
144:
50:absorbs, and thereby
1539:Analytical chemistry
1129:Coherent anti-Stokes
1084:UV–Vis–NIR "Optical"
977:fluorescent proteins
581:
348:
217:
118:
62:of the species. The
1433:Hadron spectroscopy
1223:Conversion electron
1184:X-ray and Gamma ray
1091:Ultraviolet–visible
179:is the path length.
171:molar concentration
54:, light at a given
1481:Force spectroscopy
1406:Measured phenomena
1397:Video spectroscopy
1101:Cold vapour atomic
661:
547:
542:
307:
139:
90:molar absorptivity
60:intrinsic property
1526:
1525:
1490:
1489:
1382:Spectrophotometry
1309:Neutron spin echo
1283:Beta spectroscopy
1196:Energy-dispersive
627:
624:
566:Avogadro constant
197:natural logarithm
173:of those species;
163:of that material;
16:(Redirected from
1556:
1549:Molar quantities
1514:
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1362:
1273:phenomenological
1022:Vibrational (IR)
1007:
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110:Beer–Lambert law
100:Beer–Lambert law
83:
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48:chemical species
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968:
967:External links
965:
962:
961:
942:(2): 319–326.
926:
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898:. IUPAC. 2002.
885:. IUPAC. 2002.
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1113:Near-infrared
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767:nucleic acids
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33:
19:
1515:
1503:
1483:(a misnomer)
1469:Applications
1387:Time-stretch
1278:paramagnetic
1096:Fluorescence
1014:Spectroscopy
939:
935:
929:
910:
904:
895:
882:
870:
856:Absorptivity
849:
841:
820:
812:
803:
775:
747:biochemistry
744:
713:
678:
568:
559:
332:
325:
321:
319:
207:
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201:
182:
160:
151:
103:
89:
85:
39:
35:
29:
1055:Vibrational
763:amino acids
329:wavelengths
58:. It is an
1533:Categories
1261:Two-photon
1163:absorption
1045:Rotational
827:Extinction
780:References
759:tryptophan
685:molar mass
636:3.82353216
185:absorbance
106:absorbance
56:wavelength
52:attenuates
1339:Terahertz
1320:Radiowave
1218:Mössbauer
656:ε
647:−
639:×
633:≈
630:ε
594:
585:σ
516:λ
503:ε
482:∑
478:ℓ
463:λ
449:…
420:λ
407:ε
386:∑
382:ℓ
367:λ
286:ε
265:∑
261:ℓ
228:∑
134:ℓ
128:ε
82:0.1 m/mol
32:chemistry
1505:Category
1234:Electron
1201:Emission
1151:emission
1108:Vibronic
741:Proteins
1517:Commons
1344:ESR/EPR
1292:Nucleon
1120:(REMPI)
956:2610349
751:protein
704:⁄
195:) or a
169:is the
159:is the
64:SI unit
1358:Others
1146:Atomic
954:
917:
771:260 nm
755:280 nm
714:where
152:where
34:, the
1299:Alpha
1268:Auger
1246:X-ray
1213:Gamma
1191:X-ray
1124:Raman
1035:Raman
1030:FT-IR
892:(PDF)
879:(PDF)
846:IUPAC
817:IUPAC
800:(PDF)
94:IUPAC
72:m/mol
952:PMID
915:ISBN
679:The
191:(log
104:The
88:and
68:mole
1327:NMR
944:doi
940:182
860:doi
858:".
831:doi
829:".
769:at
753:at
745:In
38:or
30:In
1535::
1332:2D
1251:UV
950:.
938:.
894:.
881:.
848:,
819:,
802:.
788:^
697:=
650:21
643:10
609:10
600:10
591:ln
574::
210::
193:10
96:.
1006:e
999:t
992:v
979:.
958:.
946::
923:.
862::
833::
734:M
728:ε
721:m
719:ε
707:M
701:ε
694:m
692:ε
659:.
623:A
619:N
613:3
603:)
597:(
588:=
572:A
569:N
538:.
533:i
529:c
525:)
520:N
512:(
507:i
497:N
492:1
489:=
486:i
475:=
472:)
467:N
459:(
456:A
442:,
437:i
433:c
429:)
424:1
416:(
411:i
401:N
396:1
393:=
390:i
379:=
376:)
371:1
363:(
360:A
354:{
326:N
322:N
305:.
300:i
296:c
290:i
280:N
275:1
272:=
269:i
258:=
253:i
249:A
243:N
238:1
235:=
232:i
224:=
221:A
208:i
204:N
177:â„“
167:c
157:ε
137:,
131:c
125:=
122:A
77:M
70:(
44:ε
42:(
20:)
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