Chemical Education Journal (CEJ), Vol. 13, No. 2 /Registration No. 13-12 /Received July 28, 2009.
URL = http://chem.sci.utsunomiya-u.ac.jp/cejrnlE.html

Safer Technique for Sustainable Sodium Extract Preparation for Extra Elements Detection

Man Singh

 

Chemistry Research Lab., Deshbandhu College, University of Delhi, New Delhi-110019, India

E-mail: mansingh50hotmail.com

 

Abstract
Chemistry laboratories are not using sustainable technique for Sodium extract preparation which is essential step for extra elements detection and then functional group analysis in organic compound in laboratories. Usual element detection method [UEDM] with breakable ignition tube [BIT] of glass is risky and polluting. Under the UEDM many BITs are broken in hot water contained in china dish. The glass is a nondegradable and the broken glass pieces with sharp edges are discarded to common places which very frequently keep cutting body parts of stray animals and even human. Very frequently sodium granules with organic compound during heating for extract preparation jump out of the BIT which accidentally damage either body parts especially eyes or catches fire with the laboratory chemicals. Using other chemicals than the sodium for extract preparation interfere detection process so Nonbreakable Sodium Ignition Apparatus (NOSIA) over the UEDM is superior and an excellent alternative with nonbreakable ignition tube [NBIT]. The NOSIA has socket and cone arrangements. The socket is fitted with NBIT at bottom and the cone is fitted with perforated part at the end to diffuse out pressure on the sodium + compound heating for ignition. Several teachers, students and researchers have performed countless tests with the NOSIA and found it very safe, nonpolluting and simple tool.

 

Keywords: Sodium, ignition, organic compound.

Contents

Introduction

Method

Experimental Operation

Operational mechanism

Sodium + compound melt

Results and discussion

Conclusion

Reference

Introduction
Huge chemical wastage for analytical analysis in chemistry laboratory is matter of great concern and adequate attentions are not paid to modernize the laboratory to cope up with situation. Several testing like mixture analysis, volumetric titration etc are essential steps to be modernized to minimize the chemicals wastes. Out of these mentioned above, a detection of extra elements is essential for identification of the functional groups of organic compounds for graduate, postgraduate classes in chemical sciences. Many organic compounds are volatile, poisonous and carcinogenic and their exposure in open ignition tube for extract preparation is dangerous [1]. Several safe methods for cleaning laboratory glassware are currently available [2] and there is urgent need to develop similar other methods for analytical uses. The solvent-based cleaning of the laboratory glass wares is performed to remove interfering residues, and represents an area of potential occupational exposure to chemicals. So smart and ecofriendly device is necessary in place of usual ignition tube method [3-5]. Safe and nonpolluting alternative to ignition tube will encourage students to perform experiments with full devotion and also the experiments using BIT with sodium and the organic compound are risky and polluting [6-8]. Though the BIT is in use for centuries and no adequate attention was drawn to eradicate a polluting and troublesome method. The NOSIA is developed to delete BIT and offer a safe method to students to eradicate the pollution and fire catching incidents in the laboratories. It has been used by hundreds of users who found it most scientific and worth for performing similar other experiments. A comparative summary of expenses used with the NOSIA and the usual BIT is prepared and a edge is evidenced with the NOSIA over the BIT. The NOSIA fusion and fusion controlling units are assembled with socket and cone arrangements [ 9,10].

 

Method
For detection of sulfur, nitrogen and halogens (Cl, Br, I) as extra elements of organic compounds are made by heating about 0.04 g sodium granule + 0.05 g organic compound in the BIT of 50 mm length and 4 mm inner diameter until it melts. The sodium granule was transferred to the ignition tube and over this an organic compound was added and the contents were positioned at bottom of a tube with an open top end during heating. In most cases the sodium on heating jumps up out of a tube and hit faces of the students and damages eyes etc. The heating was continued till a bottom of a tube holding materials was red hot and then quickly was broken in a 15 cm3 hot water contained in porcelain/china dish. About 5-8 ignition tubes were broken in a similar manner and then the mixture was heated for about 3-5 min and then was filtered off and the filtrate was used for detection purposes. Since the sodium metal quickly converts an organic compound into ionic form to facilitate an analysis of functional groups. For example C carbon and N nitrogen form salt with the Na (sodium) as Na + C + N = NaCN (sodium cyanide). An alternative of a sodium metal is not yet known and even if sodium salts are used then the anionic part of the salt interferes in analysis. Therefore an improvement in a century old method is must and urgent for safety of students in the laboratories. Also very frequently a red hot sodium granule jumps up out of the BIT and hit inflammable reagents and the compounds kept in the laboratory and catch fire. So a high risk is involved in a use of the BIT method and the same must be rectified at an earliest by developing the safe alternative methods. The experiment with BIT wastes much glass material of ignition tube used for preparation and wastes much time along a heavy risk factor when sodium metal on heating swells out and jump out of the ignition tube. To rectify the demerits of usual elemental detection, a NOSIA apparatus is used as a safe and microscale alternative with absolute safety without using BIT with no wastage of glass materials.

Experimental Operation
The experimental apparatus has two parts namely the fusion and the fusion controlling stopper units and a whole apparatus works on a socket and cone mechanism. The individual and assembled units are depicted in Figures 1 and 2 respectively. The fusion unit contains a socket at top end and the cone is fitted with a fusion controlling unit at the bottom end with perforation. The fusion unit contains an extended ignition tube (EIT) at the bottom to hold the sodium granule through a socket using a spatula and then the 0.05 g organic compound was added over the sodium granule. The EIT is depicted as BIT. When the sodium granule and organic compound are properly added in a fusion zone of the BIT then the cone is fitted in standard socket. The fusion stopper unit contains upper tube (UT) and lower tube (LT) with respect to a cone. The LT has a perforated flat glass part to prevent a jumping out of the sodium on heating with organic compound. The LT also diffuse out a pressure generated inside a bulb B on heating of the contents. The bulb B and the EIT hold the hot water. When the sodium with organic compound was red hot and then the hot water was added in the B through reverse L shaped tube [LST] attached to the bulb B. An addition of hot water lowers a gap of temperatures between the red hot sodium inside the EIT and the water to dissolve the contents to prepare a sodium extract. In experiments the hot water was added after few min when a heating of the contents stopped which becomes much safer to prevent bubbling out of contents of a mixture of bulb B. The bulb B is fitted with safety capillary SC to diffuse out a pressure if generated on heating of the organic compound with sodium together. The apparatus was clamped with LST on an ordinary laboratory stand at some height and Bunsen burner was kept below ELT to heat the organic compound + sodium (Fig.2). When the organic compound + sodium mixture was melt and mixed then the hot water was added through open top end of LST and further heated for 2-3 min for proper sodium reaction with organic compound. This final mixture is sodium extract or lasaigne solution for analysis of elements. Then the sodium extract for elemental detection as per requirements is taken out through a safety capillary directly into test tube or through a dropper via LST to perform tests. There is no need of a filter unit as no glass part of ignition tube is broken for preparation of the sodium extract. The apparatus has been used by batches of the students and teachers who found it highly suitable, safe and best alternative of a usual method of ignition tube method.

Operational mechanism
The NOSIA has fusion and fusion controlling units depicted in Figure 1 and assembly in 2. The cone unit has downwards LT and upwards UT extensions. The LT is fitted with 4 holes hood to stop jumping sodium metal and UT extension facilitate air pressure exchange. The fusion unit has a central bulb B of 17 mm inner diameter with LST of 6 mm id and 72 mm height. A pressure safety capillary is also fitted to B and bottom of this has inbuilt sodium + compound nonbreakable fusion tube. The top end of the B is in shape of standard socket to hold fusion controlling stopper unit through its standards cone. The sodium + compound are taken in a fusion unit of socket unit and cone stopper is fitted in socket depicted in Fig. 2. The NOSIA assembly was clamped with stainless steel stand. The height was adjusted with knob1 of stand. The Bunsen burner was brought near fusion unit and started to melt the sodium + compound. When fire flam stars the sodium + compound after few min starts swelling and tries to jump up but the perforated hood with 4 holes of cone does not allow and the sodium melts here only. A pressure which was generated was exchanged via air pressure tube and pressure safety capillary (Fig.2). Partly the air was also exchanged via air pressure passage of the cone downwards extension. For safety the cone and socket are fixed with metallic springs in their respective opposites hooks. The fusion tube has 12 mm height. A movable asbestos gauge is fitted on stand and occasionally is rotated to control flame. The adjustment is made with knob 2.

Sodium + compound melt
When sodium was melt then a 10-15 mL distilled and hot water is poured in B via side tube of the fusion unit and cone stopper was withdrawn then the mixture was stirred with clean glass rod. This mixture was sodium extract and used as such without filter. As per need the sodium extract was withdrawn with a glass dropper to perform chemical tests for detection of elements.

Results and discussion
A summary of used resources with percentage savings are reported in Table 1 and graphical representation in Fig. 3. Currently resources saving and multipurpose device are fitted in users and environmental priorities [6-7]. In a spirit of such priorities the NOSAI is used where no filter unit was needed with no wastage of chemicals and glass material. Each BIT contains 0.04 g organic compound and 5 BIT is used with 0.04x5= 0.2 g Na. Many times several sodium granules when taken in EIT with compound the same on heating jumps out then students takes so many granules. So average sodium per student could be 8 BIT with 0.04x8= 0.32 g Na use. If an average batch is of 40 students then the used Na is 0.32x40 = 12.8 g. In general a laboratory holds 4 batches a day then used Na is 12.8x4 = 51.2 g. Similarly a BIT is made up of 2 g glass material and then glass wastes for using 8 BIT per student is 2x8=16 g and for 40 students is 16x40 = 640 g. for 4 batches the waste glass is 640x4 = 2560 g or 2.560 kg. With BIT method, the filter assemble is used with wastage of filter paper and use of conical funnel and conical flask to contain filtrate. But with NOSIA no such additional accessories are required and no wastage of sodium as perforated hood prevents jumping of sodium granule so no additional BIT is waste.

With NBIT the 0.04 per student + 0.05 g OC are used in NBIT and very safely fused by heating so 2.560 g glass was saved and additional OC and sodium were also saved. Similarly the filling of 8 BIT with sodium granule and organic compound and their fusion takes 8x5 = 40 min with additional 40 min for boiling and filtering the extract. So with BIT the extract preparation takes 80 min against 20 min with NBIT with occupation of laboratory infrastructure for shorter time by 60 min. So for 4 batches the lab is run for 60x4 = 240 min 4 h extra with the BIT. An analysis was made for running laboratory for 4 h extra with at least 4 exhaust fans, 8 tube lights, water etc. Each fan consumed 4 units per h with 4x4x4=64 units and each tube light consumed 1 unit an h with 4x4=16 unit, with total 64+16=80 unit of electricity. Per unit cost is rupees 4/- only and total expenditure is 80x4=320 rupees only. The water used per student for cleaning of filter unit is 2 L and for 40 students is 40 x2 L = 80 L. The biogas used for heating for fusion of 8 BIT per student is 0.1 kg m-3 with 0.1 kg m-3x40 = 4.0 kg m-3 and per kg m-3 biogas is 30 rupees. So total expenditure is 4x30 = 120 rupees only on biogas. With the use of NBIT a huge saving of resources is made which is prevented to be discharged to environment as pollutants (Table 1).

 

Conclusion
The organic compounds which are taken for elemental detection after test are discharged and cause much pollution and disease. The glass materials which are broken mercilessly cause much damage to environment. The water, electricity etc are valuable recourses and their wise use is must for progress. The NOSIA is proven to be asset in organic chemistry for safety of students and control of the pollutants.

 

Acknowledgment
Author is thankful to Dr. A.P. Raste, Principal, Deshbandhu College, DU, for infrastructural support.

 

Reference

[1] Man Singh, Analytical Letters, 40 (13), 2617 (2007).
[2] Ken Schmerber, Kevin Borud, Marc Rothney and Amy Doane, Chemical Health and Safety, 12 (3), 30 (2005).
[3] I. L. Finar, "Organic Chemistry", Vol. 1, ELBS edition.
[4] R. M. Robert, J. C. Gilber, L. B. Rodewald , A. S. Wingrove, "Modern Experimental Organic Chemistry", Holt-Saunders International Ed. 1985.
[5] Man Singh, Surface and Interface Analysis, 40 (2), 76-80 (2008).
[6] Man Singh, J. Biochem. Biophys. Methods, 67 (2-3), 151-161 (2006).
[7] Man Singh, Surface and Interface Analysis, 40 (2), 76-80 (2008).
[8] Man Singh, Bulg. J. Chem. Edu., 17 (3), 192 (2008).
[9] Man Singh and Hideki Matsuoka, Surf. Rev. Lett., in press.
[10] Man Singh, Inter. J. Environ. Anal. Chem., in press.