Dears, I want to know if its halal for woman to shake hands with men especially that im working in an atmosphere when that regularly happens, i personally know that its not right and avoid the hand shaking informing them that sorry i dont to hand shakes noting that im wearing hijab of course so i end up embarrassing my self and others, im willing to do if its clearly known as haram, is this the case? and does it have to do with breaking wodoo if the intentions are only serious for business ?? appreciate your help Salam

According to the majority of the scholars It is not allowed for a man or a women to shake hands with someone who is not allowed for them (mother, father wife, sister, etc.). 

There is a hadeeth from Ma'qil ibn Yassar, saying; The prophet, peace be upon him said, "It is better for you to be stabbed in the head with an iron needle than to touch the hand of a woman who is to permissible to you." [At-Tabarani in "Al Kabir, #486. It is weak]

Ayesha, the wife of the prophet, peace be upon him, said: 'I swear by Allah, the prophet's hand never touched the hand of a woman. He would receive their oath of allegiance by spoken declaration’ (Muslim)

Umaymah bint Raqeeqah said: 'The prophet, peace be upon him, said, "I do not shake hands with women (not permissible to touch)."(An-Nasaai,and Ibn Majah )

this is the opinions of the four schools of jurisprudence (mathabs): 

With regard to the views of the four imams, they are as follows:

1 - Hanafiya (Abu Hanifa) The Hanafi madhhab:

Ibn Nujaym said: 'It is not permissible for a man to touch a woman's face or hands even when there's no risk of desire because it is haraam in principle and there is no necessity to allow it.'

[Al-Bahr al-Raa'iq, 8/219]

2 - Maliki (Imam Malik) The Maaliki madhhab:

Muhammad ibn Ahmad ('Ulaysh) said: 'It's not permissible for a man to touch the face or hand of a non-mahram woman (not related), and it is not permissilbe for him to his hand on hers without a barrier. Ayesha, may Allah be pleased with her, said: 'The prophet, peace be upon him, never accepted a woman's oath of allegiance by shaking hands with her; instead he would accept their oath of alleginace in words alone.'

According to another report: 'His hand never touched the hand of a woman, instead he would accept their oath of allegiance with words alone.'

[Manh Al-Jaleel Sharh Mukhtasar Khaleel, 1/223]

3 - Shafiy (Imam Muhammad ibn Idris Ash-Shafi) Shafi Mathab:

Imam Al-Nawawi (author of Al-Arba'een and Riyadus Salahin) said, "It is not permitted to touch a woman (not properly related) in any way.

[Al Majmoo' 4/515]

Wali A-Din Al-Iraqi said, 'This indicates the hand of the prophet, peace be upon him, did not touch the hand of any woman except for those permissible to him, whether in the case of accepting their oath of allegiance or in other cases. If he didn't do it in spite of the fact he was far above suspicion, then it is even more essential for others to heed this prohibition. It appears from the texts he didn't do it because it was forbidden for him to do so.

The fuqaha (scholars of jurisprudence) among our companions and others say it is forbidden to touch a non-mahram (not properly related) woman even if it is touching any part of her body that is not a part of her 'awrah (private area between the navel and the knees), such as her face.

But their differences of opinon occured regarding looking (at them) when there is no desire and no fear of fitnah (serious calamity). The prohibition of touching is stronger even than the prohibition of looking, and it is forbidden when there is no necessity to allow it. In the case of necessity, such as medical treatment, removing a tooth or treating the eyes, if there is no woman available to do provide the treatment, then it is allowed for a man to do it because of the necessity. 

[Tarh At-Tathreeb 7/45 #46]

4 - Hanbali (Imam Ahmad ibn Hanbal) Hanbali Mathab

Ibn Muflih said about Imam Ahmad ibn Hanbal, that he was asked about a man who shakes hands with a woman. His answer was, 'No' and it was emphatically forbidden. When he was asked about shaking hands having some cloth in between he said, 'No'.

Shaikh Taqiy ul-Din also held the view it was prohibited and gave the reason, touching is more serious than looking.
Al-Adaab al-Shari'ah, 2/257

I do believe that shaking hands with older women or man is much easer and in a case of no interest or lust at all and there is need for it and it will not be a habit, it is very dislike.  Because it is ben reported that Abu Bakr shaked hands with an old women. (Almusnnaf by AbduAlrazaq).