Turbidimetric spectrophotometer

Another procedure for the determination of TOC and its fractions in industrial effluent samples has been recently introduced [129]. A flow injection system using a gas-liquid transfer microreactor is developed, and adapted to a turbidimetric spectrophotometer. Samples are decomposed into glass vials in a microwave oven and a fraction of the CO2 is injected into a carrier gas and pumped to a glass microreactor. With minor modifications, the system allows the determination of different carbon fractions. The advantages of the proposed procedure are simplicity, low volume of samples and reagents, high frequency of determinations, and low cost. The dynamic range is 20-800 mg C/L, and the calculated LOD is 17 mg C/L. 

Turbidimetric measurements are easily performed on photometers or spectrophotometers and require little optimization. The principal concern of turbidimetric measurements is signal-to-noise ratio. Photometric systems with electro-optical noise in the range of 0.0002 absorbance unit or less are useful for turbidity measurements. ... 

For flow-based spectrophotometric or turbidimetric analytical procedures, a general-purpose spectrophotometer can be used with either a classical or a Z-shaped flow cell (Fig. 6.16, left). Classical flow cells require a cell holder to be incorporated into the spectrophotometer, and this holder is specific for the instrument concerned. Z-shaped cells (Fig. 6.16, right) are more amenable to optical fibre technology. Connecting the flow cell to the manifold tubing is generally done as specified in... 

The glass and fusion ten )eratures were determined from thermomechanical curves derived on a Kargin balance. The IR absorption spectra were obtained on a UR-10 spectrophotometer from samples made in the form of films or pellets with KBr. The turbidimetric titration of copolymer solutions was conducted with methanol. The optical density was measvired on a PEK-I photoelectric colorimeter. 

Expert MPFS system for turbidimetric determination of chioride and suifate in naturai waters. Detector spectrophotometer (410/800 nm) MP soienoid micropump RC reaction coii V soienoid vaive. 

A weighed sample is combusted in an oxygen filled flask over dilute nitric acid. Silver nitrate solution is then added and the resulting silver chloride, i.e., chlorine, estimated turbidimetrically at 420 nm using a grating spectrophotometer. 

Turbidimetric titration curves were obtained by successively adding HCl (1 N at first and then 0.1 N as the critical pH was approached) dropwise to a 250 ml solution of protein (1 gl for the individual proteins 3 gl for the EWP added NaCl concentrations of 0, 0.07, and 0.2 M were used to examine ionic strength effects) and PAA (2.5 mg dissolved in 2.5 ml), initially at pH 11.5, until the critical pH, below which association began to take place, was reached. The transmittance at 436 nm (Bausch and Lomb Spectronic 710 spectrophotometer, Rochester, NY) and pH were recorded after each addition. The critical pH was taken as that pH where the turbidity began to rise. Near the critical pH readings did not stabilize, so readings were recorded each minute without further acid addition. 

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