PART 1. POLARIZED LIGHT, POLARIMETERS, SACCHARIMETERS, AND

ACCESSORY APPARATUS

Page

Preface

I. Introduction_

II. Polarized light...

1. Nature of polarized light...

2. Inhomogeneity of light and incoherency of light beams

3. Composition of rectilinear oscillations having different

azimuths...

4. Composition of circular oscillations.

5. Polarization by double refraction___

6. Rotation of the plane of polarization-photogyric

effects...

7. Circularly polarized component beams in photogyric effects

8. Polarization of light by reflection

9. Segregation of plane polarized light beams.

(a) Polarizers from large crystals..

(b) Polaroid..

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(c) Methods of locating the plane of polarization. 24

10. Production of elliptically polarized light..

(a) By doubly refracting plates.

(b) By electric and magnetic fields.

11. Measurements on elliptically polarized light.

(a) Elliptic polarizers and halfshades..

(b) Elliptic analyzers..

(c) Elliptic compensators. -

(d) Functions of elliptic compensators and half-

shades..

12. References..

III. Measurement of rotation in circular degrees.

1. Polariscopes with circular scales.

(a) History of development..

(b) Types of polarizers and polariscopes -

(1) Laurent and Jellet polarizers.

(2) Lippich system..

(3) Sensitive-strip system.

(c) Tests of polariscopes with circular scales

(d) National Bureau of Standards equipment.

2. Light sources for circular-scale polariscopes.

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(a) Requirements and methods of testing.

(1) Crystalline purity...

(2) Planeness and parallelism of the faces__

(5) Measurement of rotation.

M793946

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(a) General.

III. Measurement of rotation in circular degrees-Continued.

3. Quartz control plates-Continued.

(b) National Bureau of Standards specifications_

(1) Purity.

(2) Planeness, parallelism

(3) Axis error_.

(4) Mounting-

(5) Dimensions_.

(c) Specifications of the International Commission

for Uniform Methods of Sugar Analysis for

quartz control plates...

(d) Certification of quartz control plates.

(e) Special tests.

4. References__.

IV. Measurement of rotation in sugar degrees..

1. Development of the saccharimeter

(a) Historical instruments__

(b) Modern instruments.

(c) Adjustable sensitivity type.

2. Basis of saccharimeter calibration..

(a) The French Sugar Scale...

(b) The German, or Ventzke, Scale-

(c) The International Sugar Scale..

(1) Herzfeld-Schönrock version.

(2) Bates-Jackson version.

(3) Amsterdam version (1932)

(4) Correction of saccharimeters to the

International Sugar Scale_

3. Additional constants of the quartz-wedge saccharimeter.

(a) Rotation ratios for quartz and sucrose solutions.

(b) Absolute rotation of normal sucrose solution..

(c) Rotatory dispersion curves of quartz and nor-

mal sucrose solution__

(d) Rotation difference, in sugar degrees, for nor-

mal sucrose solution, between λ=5461 A

and λ=5892.5 A.

(e) Thickness of the normal quartz plate.

(f) Specific rotation of sucrose.

(g) Normal weight of dextrose..

(h) Rotation of normal solution and the specific

rotation of dextrose..

(i) Specific rotations of other sugars.

(j) Conversion and scale comparison factors.

4. Light sources for saccharimeters..

(a) General..........

(b) Bichromate filter..

(c) Influence on reading.

(d) Types of lamps..

(1) Monochromatic_

(2) White light..

(a) Sucrose-

(b) Application of temperature correction by means

of a quartz control plate.

(c) Corrections for use in tropical countries.

(d) Sugar mixtures...

4. Thermostats.

(a) Water

(b) Air

5. References..

5. Certification of quartz control plates.

6. References.

V. Temperature corrections and control.

1. Quartz-wedge saccharimeter..

2. Sucrose.

3. Combination of corrections for quartz-wedge saccharimeter

and sugars.

PART 2.-RAW AND REFINED SUGARS AND SUGAR PRODUCTS

VIII. Clerget method-Continued.

2. Acid methods-Continued.

Page

(h) Influence of reagents on the rotation of su-

(g) Rotation of sugar mixtures and the evaluation

of m

(f) Effect of various reagents on the rotation of

invert sugar- - -

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(c) Invertase divisor...

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4. Detailed analytical procedure.......

(a) Considerations governing the choice of methods. 152

(b) Revised methods of Jackson and Gillis...

(2) Method I..

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(1) General methods of inversion.

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(c) Acid methods of the Association of Official Agri-

by polarization before and after inver-

sion with hydrochloric acid...

156

(d) Invertase methods of the Association of Official

Agricultural Chemists...

IX. Chemical methods for the determination of reducing sugars.

2. Methods which require filtration of cuprous oxide-

(a) Munson and Walker unified method...

170

(c) Allihn method for the determination of dextrose..

(d) Quisumbing and Thomas method....

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(e) Bertrand method...

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(f) Herzfeld method for determination of less than

1.5 percent of invert sugar in sucrose-

(g) Meissl and Hiller method for determining invert

sugar admixed with sucrose in all proportions.. 175

(h) Brown, Morris, and Millar method for reducing

sugar in molasses..
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IX. Chemical methods for the determination of reducing sugars-Con.

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3. Determination of copper..

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(a) General...

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(b) Gravimetric methods..

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(c) Electrolytic deposition from nitric acid solution.. 180

(d) Thiosulfate method..

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(e) Permanganate method.

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4. Volumetric methods...

(f) Dichromate methods...

(1) Electrometric..

(2) Colorimetric..

(a) Lane and Eynon method.

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(c) Schoorl method for invert sugar in cane molasses. 192

(d) Methods for small percentages of invert sugar in

(a) Somogyi modification of Shaffer and Hartmann

micromethod for dextrose.......

(b) Benedict modification of Folin and Wu method.

(c) Ferricyanide micromethod of Hagedorn and

Jensen...

6. Colorimetric and visual methods...

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(a) Pot method of Main for determination of reduc-

ing sugars in raw sugars and similar products.. 199

(b) de Whalley method for the determination of in-

vert sugar in refined white sugars.---

7. Electrometric method for the determination of reducing

201

sugars..

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8. Selective methods..

203

(a) Jackson and Mathews modification of Nyns

method for levulose...

(b) Hinton and Macara method for levulose in con-

densed milk.

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(c) Sichert and Bleyer modification of Barfoed

copper acetate method for monoses__ -

(d) Monier-Williams modified Barfoed method for

monose sugars in condensed milk..

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(e) Iodometric determination of aldoses.

(f) Hinton and Macara chloramine-T method for

the determination of aldoses..

(a) Recapitulation of previously described methods. 215

(b) Invert sugar by polarization at two temperatures. 215

(c) Levulose by polarization at two temperatures... 217

(a) Galactose by mucic acid precipitation.

218

(e) Determination of mannose as phenylhydrazone - 218

(f) Determination of arabinose as diphenylhydra-

zone

(g) Determination of uronic acids..

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