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This work describes preparation and application of "homemade" chloride ISE enriched with iron oxides or zinc oxide nanoparticles. The prepared chloride ISE membrane was made of AgCl:Ag2S:PTFE = 1:1:2 and AgCl:Ag2S:PTFE = 2:1:2 enriched with mentioned nanoparticles in ratio 0.5-1.2 wt.%. Prepared membranes were used for chloride determination in perchloric acid (pH = 0-2) and acetic buffer (pH = 4-4.75). Due to the low method price, simplicity and a reasonably fast way of usage, it was considered as a possibility for chloride determination in high acid media. Two of prepared membranes (M1 and M4) have shown best characteristics. M1 showed linear response range for chloride between 2.0×10 −6 and 1×10 −1 mol L −1 , with a detection limit of 2.24×10 −6 mol L −1 and potential change of 44.39 mV per decade. M4 showed linear response range for chloride between 4.2×10-6 to 1×10-1 mol L −1 , limit of detection of 1.39×10-6 mol L −1 with potential change of 24.79 mV per decade at pH = 0.

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A new modified ion-selective electrode with membranes of LaF3 single crystals with different internal contacts (solid steel or electrolyte) and with FexOy nanoparticles as loading was developed. The best response characteristic with linear potential change was found in the fluoride concentration range from 10−1 to 3.98 × 10−7 M. The detection limit for the electrolyte contact was determined at 7.41 × 10−8 M with a regression coefficient of 0.9932, while the regression coefficient for the solid contact was 0.9969. The potential change per concentration decade ranged from 50.3 to 62.4 mV, depending on whether the contact was solid or electrolytic. The prepared modified electrode has a long lifetime, as well as the possibility of application in different positions (solid contact), and it can also be used for the determination of iron ions. The electrode characterization was performed with scanning electron microscopy and elemental analysis with the technique of electron-dispersive X-ray spectroscopy.

We describe a new method using flow-injection analysis with spectro-photometric detection, suitable for the determination of N-acetyl-l-cysteine (NAC). The proposed method is appropriate for the determination of NAC in reaction with Pd2+ ions in the concentration range from 1.0 × 10−5 mol L−1 to 6.0 × 10−5 mol L−1. The detection limit NAC was 5.84 × 10−6 mol L−1 and the recorded relative standard deviation of the method is in the range from 1.67 to 4.11%. NAC and Pd2+ form complexes of Pd2+:NAC molar ratios of 1:1 and 1:2, depending on the ratio of their analytical concentrations. The cumulative conditional stability constant for the Pd(NAC)22+ complex is β12’ = 2.69 × 109 L2 mol−2. The proposed method was compared with the classic spectrophotometric determination of NAC, using the same reagent, PdCl2, and had shown certain advantages: a) shorter analysis time; b) the use of smaller volumes of sample and reagents, which make the proposed method cheaper and faster for NAC determination in real samples without sample pretreatment.