Use of Perchloryl Fluroide in Flame Photometry - ACS Publications

less noncorrosive gas with a charac- teristic sweet odor. It is storable as a liquid under pressure and exhibits oxidizing properties. Perchloryl fluo...
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Use of Perchloryl Fluoride in Flame Photometry Solutions were prepared from the chlorides of lithium, sodium, barium, magnesium, strontium, calcium, iron, chromium, and copper in the concentration of 1000 p.p.m. of the metal ions. Water, dimethylformamide, and dimethylsulfoxide were used as solvents. Spectra were obtained for these solutions in both the acetylene-oxygen and the hydrogen-perchloryl fluoride flames. Data concerning the effect of the hydrogen-fluorine flame were obtained from Collier (1).

SIR: A preliminary study of the possible use of perchloryl fluoride as an excitation fuel in flame photometry produced encouraging results. Perchloryl fluoride (PF), C103F, is a colorless noncorrosive gas with a characteristic sweet odor. It is storable as a liquid under pressure and exhibits oxidizing properties. Perchloryl fluoride and hydrogen, as a gas combination, burned in a modified Beckman burner and produced an easily controlled, bluish flame with sufficiently low background for use as an excitation source. Less than 2% background emission was produced with a 0.2-mm. slit width. The type spectra produced by the hydrogen-perchloryl fluoride flame with various series of solutions n-ere surveyed t o determine the effectiveness of this gas combination in flame photometric work. The various lines and bands produced by three gas combinations were compared, including acetyleneoxygen, hydrogen-fluorine, and hpdrogen-perchloryl fluoride.

RESULTS

The hydrogen-perchloryl fluoride gas combination produced a satisfactory excitation source for flame photometry, which is easily controlled and has a low background. A flow rate of 4000 to 5000 cc. of perchloryl fluoride per minute and 11,000 to 12,000 cc. of hydrogen per minute provided the best flame conditions. Below this flow rate for the perchloryl fluoride, the aspiration is insufficient to provide proper flame intensity. Ahoye this rate, the intensity again decreases and the

EXPERIMENTAL

A standard acetylene-oxygen burner supplied by Beckman Instruments, Inc., was modified for this work. An automatic recording spectrophotometer was used as a detecting instrument. The monochromator unit was the Beckman Model DC spectrophotometer with the automatic recording unit supplied by Warren Electronics, Inc. A Fischer-Porter C-clamp Flowrator was used to measure the flow rate of the atomizing gas. The burner was mounted in place of the light source for the automatic recording spectrophotometer. The distance from the burner to the lamp housing was 8 inches. A double convex quartz lens was used to focus the light emitted by the flame upon the slit entrance of the instrument.

flame becomes unsteadj-. The tempersture of this flame has not yet been determined. The acetylene-oxygen flame produced a background of 2 to 5% emission in the visible region when a 0.05-mni. slit was used, and the reported maximum flame temperature is 3410" K. The hydrogen-fluorine flame produced about 1% background emission in the visible region with a 0.05-mm. slit, and the reported maximum flame temperature ie 4300" K. Figures 1 and 2 illustrate the type spectra produced b y the three flames under consideration. Comparison of the radiation emitted by the hydrogenperchloryl fluoride, acetylene-oxygen , and hydrogen-fluorine flames upon injection of metal salt solutions, s h o w that primarily atomic line and metal oxide band radiation is produced by the acetylene-oxygen flame (Figure 1) and primarily atomic line and metal fluoridP and chloride band radiation is produced b y the hydrogen-perchloryl fluoride flame (Figure 1). According to Col!ier (I), the hj-drogen-fluorine flame pro-

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1000 P P M MO*IR DMF

1000 P P M MO*IN DMF

HE- P F O . l r r S L I T

C.He-

0. 0 . 1 S~L I~T I EROKW L I N E )

( S O L I D LINE) 1 MECI

,

WAVE L E N G T H

Figure 1.

Relation between wave length and intensity 1.0

OF

1000PPM Mot+

CAF

500 PPM Cl"8

He0

H E - PF

0.05Nu S L I T

H e - F,

.Mo

IN

MttI* OMF

0.PuuSLIT

- Ma

CAF

>,

F

Ma A

350

500

400

600

700 WAVE L E N G T H

WAVE LENGTH

Figure 2.

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Relation between wave length and intensity

ANALYTICAL CHEMISTRY

Figure 3.

Relation between wave length and intensity

duced primarily atomic line and metal fluoride band radiation for the elements studied (Figure 2). Both the hydrogenfluorine and the hydrogen-perchloryl fluoride flames are capable of producing the same type of radiation; however, the lines and bands produced b y the former are generally more intense. I n general, the solvent does not affect the type of radiation observed for a particular element when excited with the hydrogen-perchloryl fluoride flame, but the organic solvents seem t o produce higher intensity under similar conditions. A comparison of the spectra produced by these three flames for 1000 p.p.m. of magnesium is shown in Figures 1 and 2. The acetylene-oxygen flame produced two broad magnesium oxide bands in the region between 360 and 400 mp, while the hydrogen-perchloryl fluoride flame produced two prominent, fairly narrow bands and two less proniinent bands in this region. The two prominent bands are a magnesium fluoride band at 359.4 nip and a magnesium chloride band a t 377.0 mp. The two less prominent bafids are also magnesium chloride bands. These bands were identified Tvith the aid of tables compiled by Pearse and Gaydon ( 2 ) for the identification of molecular spectra. I n Figure 2, the spectrum of 1000 p.p.m. of magnesium in water shows one

170. ANDRE

very intense magnesium fluoride band at 359.4 mp and two less intense magnesium fluoride bands when excited by the hydrogen-fluorine flame using a 0.05-mm. slit. A solution of 500 p.p.m. each of calcium and magnesium in dimethylformamide produced a spectrum characteristic of both individual elements, with no overlapping of prominent lines (Figure 3). The lines and bands produced for calcium were much more intense than those for magnesium. The same type of spectrum was produced for the calcium-magnesium mixture in mater but with less intensity.

were a minor interference with the H3 PF flame. TWOvery prominent bands are observed when magnesium is excited by the hydrogen-perchloryl fluoride flame and a mixture of magnesium and calcium provided a spectrum characteristic of both individual elements with no overlapping of prominent lines or band. which suggest possible analytical adaptation. The type of radiation for a particular element is not affected b y the solvent used, although the organic solvents produced better sensitivity than the corresponding water solutions.

+

ACKNOWLEDGMENT CONCLUSIONS

A modified Beckrnan burner can be used for the hydrogen-perchlory1 fluoride gas combination to produce a satisfactory flame with very low background, which is easily controlled and applicable to use as an excitation source in flame photometry. Primarily atomic line and metal fluoride and chloride band radiation was produced upon excitation of the various elements by the hydrogenperchloryl fluoride flame. Satisfactory spectra are produced by this gas combination for inany metals which would be suitable for analytical purposes. Despite high oxygen content in the flame, oxide bands of refractory metal oxides

The authors wish to thank Pennsalt Chemicals Corp. for supplying the perchloryl fluoride used in this work. LITERATURE CITED

(1) Collier, H. E., unpublished Ph.D.

thesis, Lehigh University, June

1955. (2) Peyse, R. TV.,

Gaydon, A. G., ‘Identification of Molecular Spectra,” Chapman & Hall, London, 1941.

GEORQEE. SCHXkcCH EARL J. SERFASS Chemistry Department Lehigh University Bethlehem, Pa. RECEIVED for review November 2, 1957. Accepted dpril 12, 1958.

Germanium Bismuthate, Ge,Bi,O,, DURIF

Laboratoire d’Electrostatique et d e Physique du MBtal, lnstitut Fourier, Grenoble, France

G

bisniuthate n-as prepared b y heating slovJy u p t o 850” C. a mixture of bismuth trioxide ERMAPI‘IUM

Table I.

h1:l 211 310 312

100 422

)f,721 j!: 530’ 43;3(

X-Ray Powder Diffraction Data for Germanium Bisrnuthatea

dobsd.

dcaicd.

I,.is,

4.24 3.26 2.76 2.59 2.12

4.30

niS

2.04 1.915 1.798

!&’; 1.704 620‘ 541 6:31 34 more

and germanium dioxide (1). This cornpound is a n isomorph of the mineral eulytine, Si3Bi4012,also called agricolite.

3.33

S

2.06 1.922

S mW in3 mS IT’

1.805

n1

1.708 1.664 1.624 1 552

mS mTV

2.81 2.63 2.15

hkl 444 550

dobad.

doalcd.

I\.,,.

1.514

1.519

IT

1 E; 1 552 1

1.436

1.489

m3

1.431

1.133

m

642 7327

1.404 1.335

1.407

m m\J7

;:;,f A,51/

. . ~

1.337

1 296 1.298 mS 554 mS 653 1.258 1.259 TV mS indexable lines were observed and measured with copper radiation

1.661 1 G19 1 548

X-RAYDIFFRACTIOX DATA System. Cubic, cell size. a = 10.527 0.003 -1. Formula weights per cell. 4. Density. 7.049 grams per cc. (calculated). Space group. T: -143d. Precision measurements have been made both with powder camera (filtered cobalt and copper radiations) and with the x-ray diffractometer (monoehroinatized copper radiation K a l ) (Table 1). LITERATURE CITED

(1) Durif, A., Compt. rend. 244, 2815-17 (1957).

CRYSTALLOGRAPHIC data for publication in this section should be sent to W. C. McCrone, 500 East 33rd St., Chicago 16, Ill. VOL. 30, NO. 6, JUNE 1958

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