## 1 Introduction  
Chemical flow-based analysis was first introduced in the middle of 20\({}^{\text{th}}\) century [1]. This technique has been developed from an attempt to collect the fractions eluted in the chromatographic separation process in an industrial plant. At the end of 1950s, such a concept was outlined in a practical way and become a sample delivery system within a fluid, known as segmented flow analysis (SFA) [2]. Using air segments within the flowing stream in the SFA technique increases the homogeneity between the sample and reagent. Many laboratories rapidly accepted this approach. But the two main drawbacks are the debubble processing of the fluid before entering the detector and the high reagent and sample consumption due to the continuous flow. A new technique, flow injection analysis (FIA) [3], was introduced by [PERSON] in 1975. It became one of the most popular techniques for analytical applications within a short period of time because of its simplicity and ease of use. An injection valve (6-port valve with a small-size sample loop) is used to minimize the sample consumption. No air segments are required in this approach, thus, it offers more simplicity and robustness. Easy implementation together with the high sample throughput is the main advantages, whereas the high reagent consumption rate is unsolved. The FIA was originally designed for an automated system. It has been used as a general solution for handling or sample introduction systems. A current literature survey reveals that this technique can also be used in many branches of analytical research such as a routine methodology in chemical monitoring processes, chemical and bioanalytical sensors, and clinical applications including food and drug industries. Moreover, numerous variant techniques based on FIA, such as sequential injection (SIA), batch injection (BIA) [4-7], multicommuted flow injection analysis (MCFIA), all injection analysis (AIA) [8], multisyringe flow injection analysis (MSFIA), and multipumping flow injection analysis (MPFIA), have been developed over the past few decades. However, FIA is still the most widely used technique because no complicated instruments or computers are required. In SIA [9], sample and reagent segments are sequentially introduced in a holding coil by using selection valve before the sample and reagent are impelled by piston pump through the mixing coil toward the detector. This process was controlled by a microprocessor or software. The great advantage of this technique is an important saving in the samples and reagents, whereas a low analysis rate and complicated software, including an expensive instrument setup are the main drawbacks. Another approach, BIA, is conceptually similar to FIA in that the injected sample zone is transported toward the detector. In this technique, a small liquid sample is injected toward the nearby flat sensor surface resulting in a transient signal similar to those in the FIA readout. Although this technique is considered a \"non-flow injection-based technique\" from the fact that no transport of either sample or reagents takes place within the tubing, it has been demonstrated to be a very attractive approach for automation analysis. In MCFIA, the sample injector used in FIA is replaced by three-waysolenoid commutation valves, which are controlled by computer. The injected volume can also be adjusted by controlling the commutation timing via software. Since the sample and reagents are injected into the flow system only when necessary, the consumption rate and waste generation can be minimized. Peristaltic pumps are still the most common liquid-propelling drives in MCFIA. The flexible pump tubing needs to be replaced periodically. This factor is one of the main problems of this technique. The pump tubing lifetime can be eliminated in MSFIA. This technique is based on multiple syringes which are used as liquid-propelling devices. MSFIA takes advantage of manifold operation and high sample throughput of FIA together with the robustness and versatility of SIA.